Class 9

Andhra Pradesh BIEAP AP Inter 1st Year Zoology Study Material 9th Lesson Chemical Coordination and Integration Class 11 Textbook Exercise Questions and Answers.

Chemical Coordination and Integration Class 11 Questions and Answers AP Inter 1st Year Zoology 9th Lesson

I. Chemical Coordination and Integration Multiple Choice Questions (1 Mark)

Question 1.
Which of the following is not an endocrine gland ?
(1) Pituitary
(2) Pineal
(3) Pancreas
(4) Salivary glands
Answer:
(4) Salivary glands

Question 2.
The posterior pituitary is under the direct neural regulation of the……….
(1) hypothalamus
(2) cerebellum
(3) epithalamus
(4) medulla oblongata
Answer:
(1) hypothalamus

Question 3.
The pituitary gland is located in a bony cavity called………..
(1) glenoid cavity
(2) acetabulum
(3) sella tursica
(4) pars intermedia
Answer:
(3) sella tursica

Question 4.
Oxytocin and vasopressin are synthesized in………
(1) posterior pituitary
(2) anterior pituitary
(3) hypothalamus
(4) thyroid
Answer:
(3) hypothalamus

Question 5.
Excess secretion of growth hormone in adults leads to…….
(1) Dwarfism
(2) Acromegaly
(3) Graves’ disease
(4) Addison’s disease
Answer:
(2) Acromegaly

Question 6.
Which hormone stimulates contractions of the uterus at the time of child birth and milk ejection from the mammary glands?
(1) Vasopressin
(2) Oxytocin
(3) Thyroxine
(4) Insulin
Answer:
(2) Oxytocin

Question 7.
Assertion (A): Vasopressin is called antidiuretic hormone.
Reason (R) : It reduces loss of water through urine.
(1) Both (A) and (R) are true, and R is the correct explanation of (A)
(2) Both (A) and (R) are true, but R is not the correct explanation of (A)
(3) (A) is true, but (R) is false
(4) (A) is false, but (R) is true
Answer:
(1) Both (A) and (R) are true, and R is the correct explanation of (A)

Question 8.
Match the following.

Column-I	Column-II
a) T4	i) Hypothalamus
b) PTH	ii) Thyroid
c) GnRH	iii) Pituitary
d) LH	iv) Parathyroid

(1) (a)-ii, (b)-iv, (c)-i, (d)-iii
(2) (a) – i, (b)- iii, (c)-iv, (d)-ii
(3) (a)-iii, (b)-ii, (c)-iv, (d)-i
(4) (a)-iv, (b)-iii, (c)-i, (d)-ii
Answer:
(1) (a)-ii, (b)-iv, (c)-i, (d)-iii

Question 9.
Circulating levels of calcium ions regulate the secretion of………
(1) parathyroid hormone
(2) adrenaline
(3) insulin
(4) glucagon
Answer:
(1) parathyroid hormone

Question 10.
Prolonged hyperglycemia leads to………
(1) Diabetes insipidus
(2) Diabetes mellitus
(3) Addison’s disease
(4) Cretinism
Answer:
(2) Diabetes mellitus

Question 11.
Which of the following is not a symptom of Cretinism ?
(1) Stunted growth
(2) Low IQ
(3) Deafness and mutism
(4) Decalcification of bones
Answer:
(4) Decalcification of bones

Question 12.
Which of the following is mismatched ?
(1) Hypothyroidism – Goitre
(2) Hyperthyroidism-Graves’ disease
(3) Hypersecretion of corticoids – Addison’s disease
(4) Hypersecretion of growth hormone – Gigantism
Answer:
(3) Hypersecretion of corticoids – Addison’s disease

Question 13.
The hormone that stimulates the secretion of HCl and pepsinogen from gastric glands
(1) Gastrin
(2) Insulin
(3) Secretin
(4) Cholecystokinin
Answer:
(1) Gastrin

Question 14.
Which of the following hormones is an amino acid derivative ?
(4) Growth hormone
(1) Insulin
(2) Glucagon
(3) Epinephrine
(4) Growth hormone
Answer:
(3) Epinephrine

Question 15.
Which of the following does not act as a second messenger in hormonal action ?
(1) Cyclic AMP
(2) IP₃
(3) FSH
(4) Ca⁺²
Answer:
(3) FSH

II. Chemical Coordination and Integration Fill in the Blanks (1 Mark)

Question 1.
The non-nutrient chemicals which act as intercellular messengers are called ………..
Answer:
Hormones

Question 2.
Over secretion of …………… hormone leads to gigantism.
Answer:
Growth

Question 3.
The composite gland that acts as both exocrine and endocrine gland is…………
Answer:
Pancreas

Question 4.
Follicle stimulating hormone and ………… hormone are called gonadotropins.
Answer:
Luteinizing

Question 5.
Iodine is essential for the synthesis of ……….. hormones.
Answer:
Thyroid

Question 6.
The main mineralocorticoid produced by the adrenal cortex in the human body is ………..
Answer:
Aldosterone

Question 7.
Basal metabolic rate is regulated by ………. hormones.
Answer:
Thyroid

Question 8.
The enlargement of ………. gland is called Goitre.
Answer:
Thyroid

Question 9.
Chemically cortisol is a ………. hormone.
Answer:
Steroid

Question 10.
Underproduction of glucocorticoids by adrenal cortex leads to ………. disease.
Answer:
Addison’s

III. Chemical Coordination and Integration One Word Answer Questions (1 Mark)

Question 1.
What are the secretions of the endocrine glands called ?
Answer:
Hormones

Question 2.
Which gland produces melatonin hormone?
Answer:
Pineal gland

Question 3.
Name the bilobed gland located on either side of the trachea.
Answer:
Thyroid

Question 4.
How many parathyroid glands are found in the human body?
Answer:
Four (4)

Question 5.
Which cells of Islets of Langerhans secrete glucagon hormone ?
Answer:
α (Alpha) cells

Question 6.
Which mineral is essential for the synthesis of thyroid hormones ?
Answer:
Iodine

Question 7.
Which disorder is treated with insulin therapy ?
Answer:
Diabetes mellitus

Question 8.
Which hormone supports pregnancy in women ?
Answer:
Progesterone

IV. Chemical Coordination and Integration Very Short Answer Questions (2 Marks)

Question 1.
Define the following :
A) Endocrine gland
B) Hormone
Answer:
A) Endocrine gland : An endocrine gland is a ductless gland that releases its secretions (hormones) directly into the bloodstream to be transported to target organs.
B) Hormone : A hormone is a non-nutrient chemical messenger produced in trace amounts by endocrine glands that regulate physiological functions of the body.

Question 2.
Which hormonal deficiency is responsible for the following ?
A) Cretinism
B) Diabetes mellitus
Answer:
A) Cretinism : Cretinism is caused due to the deficiency of thyroid hormones, usually resulting from hypothyroidism during pregnancy. This condition often occurs due to a lack of iodine in the mother’s diet. Hypothyroidism during pregnancy causes defective development and maturation of the growing baby leading to stunted growth (cretinism), mental retardation, low intelligence quotient, abnormal skin, deaf-mutism, etc.

B) Diabetes mellitus: Diabetes mellitus is caused by the deficiency or absence of the fromone insulin, which is responsible for regulating blood glucose levels through urine and formation of harmful compounds known as ketone bodies.

Question 3.
What is acromegaly? Name the hormone responsible for this disorder.
Answer:
Acromegaly is a condition caused by excess secretion of growth hormone (GH) in adults leading to abnormal enlargement of bones, especially in the face and limbs.

• Acromegaly may lead to serious complications and premature death if unchecked.
• It is due to hypersecretion of growth hormone (GH) in adults.

Question 4.
Which hormone is called antidiuretic hormone? Write the name of the gland that releases it.
Answer:
The antidiuretic hormone (ADH) is vasopressin. It is released by the posterior pituitary but synthesized in the hypothalamus.

Question 5.
Name the endocrine gland that degenerates in old individuals. What important role does it play in the immune system ?
Answer:
Thymus is the gland that degenerates with age. It secretes thymosins which help in the differentiation of T-lymphocytes and boost immune responses.

Question 6.
Distinguish between Diabetes mellitus and Diabetes insipidus.
Answer:

Diabetes Mellitus	Diabetes Insipidus
1. It is due to deficiency of insulin.	1. It is due to deficiency or failure of ADH (vasopressin).
2. It is characterized by High blood sugar (hyperglycemia), excess glucose and ketone bodies in urine.	2. It is characterized by excessive urination and dehydration.

Question 7.
What are “Islets of Langerhans” ?
Answer:

• It is the endocrine part of pancreas. Among the pancreatic acini several/ many cells are present called “Islets of Langerhans”.
• It contains α – cells secrete glucagon and β – cells secrete insulin.

Question 8.
Which gland secretes fight or flight hormones ? Where is it located ?
Answer:
The adrenal medulla secretes adrenaline (epinephrine) and noradrenaline (norepinephrine)-the fight or flight hormones. It is located above each kidney.

Question 9.
What are Androgens ? Which cells of the testes secrete them ?
Answer:

• Androgens are male sex hormones (mainly testosterone) that regulate male secondary sexual characteristics and spermatogenesis.
• They are secreted by the Leydig cells (interstitial cells) of the testes.
  E.g. : Testosterone

Question 10.
What is erythropoietin? What is its function?
Answer:
Erythropoietin is a peptide hormone secreted by the juxtaglomerular cells of the kidney. Its function is to stimulate erythropoiesis (formation of red blood cells).

V. Chemical Coordination and Integration Short Answer Questions (4 Marks)

Question 1.
List out the names of the endocrine glands present in human beings and mention the hormones they secrete.
Answer:
The human body has the following endocrine glands :

• Pituitary gland : Secretes growth hormone (GH), prolactin (PRL), Thyroid Stimulating Hormone (TSH), Adrenocorticotropic Hormone (ACTH), Luteinizing Hormone ( LH), Follicle Stimulating Hormone (FSH), Melanocyte Stimulating Hormone (MSH), oxytocin, and vasopressin (ADH).
• Pineal gland: Secretes melatonin which regulates sleep-wake cycles.
• Thyroid gland : Secretes thyroxine (T₄), triiodothyronine (T₃), and thyrocalci- tonin (TCT).
• Parathyroid glands: Secrete parathyroid hormone (PTH) that regulates blood calcium levels.
• Thymus gland : Secretes thymosins important for T-cell development and immunity.
• Adrenal glands : Medulla secretes adrenaline and noradrenaline; cortex seretes cortisol, aldosterone, and small quantities of androgens.
• Pancreas (Islets of Langerhans): Secretes insulin (p – cells) and glucagon (a – cells).
• Testes: Secrete androgens like testosterone.
• Ovaries: Secrete estrogen and progesterone.
• Other hormone-secreting tissues: Heart (ANF), kidney (erythropoietin), and gastrointestinal tract (gastrin, secretin, CCK, GIP).

Question 2.
Diagrammatically indicate the location of various endocrine glands in the human body.
Answer:

Question 3.
Write short notes on the functions of the following hormones.
a) Parathyroid hormone b) Aldosterone c) Thymosins d) Insulin
Answer:
a) Parathyroid Hormone (PTH):

• Humans have four parathyroid glands located on the posterior side of the thyroid gland, with one pair in each two lobes of the thyroid.
• These glands secrete a peptide hormone known as parathyroid hormone (PTH), which is regulated by the calcium ion concentration in the blood.
• PTH increases blood calcium (Ca²⁺) levels by acting on bones to stimulate reasorption or breakdown (demineralization).
• It also promotes reabsorption of Ca²⁺ in the renal tubules and enhances calcium absorption from the intestines.
• Thus, PTH is called a hypercalcemic hormone as it raises blood calcium levels and works with thyrocalcitonin (TCT) to maintain calcium balance in the body.

b) Aldosterone:

• Aldosterone is the primary mineralocorticoid hormone in the body.
• It acts mainly on renal tubules, promoting the reabsorption of sodium (Na⁺) and water, while facilitating the excretion of potassium (K⁺) and phosphate ions.
• Aldosterone plays a key role in maintaining electrolyte balance, fluid vol­ume, osmotic pressure, and blood pressure.

c) Thymosins:

• The thymus is a lobular gland situated between the lungs, behind the sternum, on the ventral side of the aorta.
• It is crucial for the development and maturation of the immune system.
• The thymus secretes a group of peptide hormones known as thymosins.
• Thymosins are essential for the differentiation of T-lymphocytes, provid­ing cell-mediated immunity.
• They also aid in the production of antibodies, supporting humoral immu­nity.
• In old age, the thymus shrinks, leading to reduced thymosin production and consequently weaker immune responses in elderly individuals.

d) Insulin:

• Insulin is a peptide hormone that plays a vital role in maintaining blood glucose levels.
• It primarily targets hepatocytes (liver cells) and adipocytes (fat cells), enhancing the uptake and utilization of glucose.
• Insulin also stimulates the conversion of glucose into glycogen (a process called glycogenesis) in the target cells.
• Glucose homeostasis in the blood is regulated by the coordinated action of insulin and glucagon.

Question 4.
Write a note on the mechanism of hormone action.
Answer:
1. Hormone-Receptor Interaction:
i. Hormones exert their effects by binding to specific receptor proteins lo­cated in their target tissues.
ii. These receptors can be of two main types :

• Membrane-bound receptors – located on the surface (cell membrane) of target cells.
• Intracellular receptors – located inside the target cells, typically in the nucleus.

iii. When a hormone binds to its receptor, it forms a hormone-receptor complex.
iv. Each receptor is highly specific to a particular hormone.
v. This hormone-receptor complex triggers a cascade of biochemical reactions that ultimately lead to physiological responses in the target tissue.

2. Classification Based on Chemical Nature: Hormones are grouped based on their chemical structure into the following categories :

• Peptides, Polypeptides, and Protein Hormones
  Examples : Insulin, Glucagon, Pituitary hormones, Hypothalamic hormones, Thyrocalcitonin (TCT), Parathyroid hormone (PTH), Thymosins.
• Steroid Hormones
  Examples : Cortisol, Testosterone, Estradiol, Progesterone.
• Amino Acid Derivatives (Biogenic Amines)
  Examples: Epinephrine.
• Iodothyronines (Thyroid Hormones)
• Hormones which interact with membrane-bound receptors normally do not enter the target cell, but generate second messengers (E.g: Cyclic AMP, IP₃, Ca⁺⁺etc.) Which in turn regulate cellular metabolism.
• Hormones which interact with intracellular receptors (E.g: Steroid, Iodothyronines, etc.) mostly regulate gene expression or chromosome function by the interaction of hormone-receptor complex with the genome.
• Cumulative biochemical actions result in physiological and developmental effects.

(a) Diagrammatic representation of mechanism of Protem Hormone

(b) Diagrammatic representation of mechanism of Steroid Hormone

Question 5.
Describe the role of hypothalamus as a neurosecretory endocrine organ.
Answer:

• It is the Master Endocrine gland of the body.
• The hypothalamus basal part of Diencephalon (part of fore brain) and hypothalamus regulates a wide spectrum of body functions. It contains several groups of neurosecretory cells called nuclei, which produce hormones.
• These hormones regulate synthesis and secretion of anterior pituitary hormones. However, these hormones produced by hypothalamus are of 2 types. Releasing hormones (stimulates secretion of pituitary hormones) and inhibiting hormones (Inhibit secretions of pituitary hormones).
• For example, a hypothalamic hormone called Gonadotrophin releasing hormone (GnRH) stimulates to anterior pituitary for synthesis and release of Gonadotrophins (FSH/LH).
• On the other hand Somatostatin (Growth hormone inhibiting hormone) from hypothalamus inhibits release of growth hormone from anterior pituitary.
• These hormones (Releasing hormone or Inhibiting hormone) originating in hypothalamic neurons, pass through axons of neuron of hypothalamic nuclei and are released from their nerve endings into blood vessels.
• These reach anterior pituitary gland through a portal circulatory system and regulate functions of anterior pituitary.
• Posterior pituitary is under direct neural regulation of hypothalamus.

Question 6.
Give an account of the secretions of the pituitary gland.
Answer:
The pituitary gland is divided into three parts : anterior pituitary (adenohypophysis), intermediate lobe (pars intermedia), and posterior pituitary (neurohypophysis).
1. The anterior pituitary (adenohypophysis) secretes six important hormones :

• Growth Hormone (GH) – promotes overall growth of the body.
• Prolactin (PRL) – stimulates milk production in the mammary glands.
• Thyroid Stimulating Hormone (TSH) – regulates the secretion of thyroid hormones.
• Adrenocorticotropic Hormone (ACTH) – stimulates the adrenal cortex to release cortisol.
• Luteinizing Hormone (LH) and Follicle Stimulating Hormone (FSH) – regulate the function of the gonads (testes and ovaries).

2. The intermediate lobe (pars intermedia) secretes Melanocyte – Stimulating Hormone (MSH), which controls skin pigmentation.

3. The posterior pituitary (neurohypophysis) stores and releases two hormones Oxytocin and Vasopressin (ADH) – which are synthesized by the hypothalamus.

• Oxytocin causes uterine contractions during childbirth and milk ejection.
• Vasopressin helps in water reabsorption in the kidneys and maintains water balance in the body.

Thus, the pituitary gland plays a vital role in regulating growth, metabolism, reproduction, and fluid balance in the body.

Question 7.
Explain how hypothyroidism and hyperthyroidism can affect the body.
Answer:
Hypothyroidism:

• It is a condition caused by the deficiency of thyroid hormones T₃ & T₄ decrease, often due to a lack of iodine in the diet.
• In pregnant women, it can lead to cretinism in the developing baby, resulting in stunted growth, mental retardation, low intelligence quotient (IQ), abnor’mal skin, and deaf-mutism.
• In adult women, hypothyroidism can cause irregular menstrual cycles.
• It may also lead to an enlargement of the thyroid gland, known as “Simple goiter”.

Hyperthyroidism:

• It occurs when there is an excessive secretion of thyroid hormones T₃ & T₄.
• This can happen due to thyroid cancer or the development of nodules in the thyroid gland.
• A severe form of hyperthyroidism is called ‘Exophthalmic goitre or Graves’ disease, which is characterized by protrusion of the eyeballs, enlargement of the thyroid gland, increased basal metabolic rate (BMR), and weight loss.
• It adversely affects overall body physiology.

Thus, both hypothyroidism and hyperthyroidism significantly disrupt the body’s metabolism, development, and hormonal balance.

Chemical Coordination and Integration Class 11 Extra Questions and Answers

I. Multiple Choice Questions (1 Mark)

Question 1.
Why do steroid hormones act on intracellular receptors while peptide hormones mediate their function through cell surface receptors?
(1) Steroids cannot bind to cell surface proteins
(2) Steroids are not electrostatically stable on membranes
(3) Steroids are hydrophobic, hence can pass the membrane
(4) Steroids are hydrophilic, hence cannot bind proteins
Answer:
(2) Steroids are not electrostatically stable on membranes

II. Fill in the Blanks (1 Mark)

Question 1.
Erythropoiesis is stimulated by a peptide hormone called………..
Answer:
Erythropoietin

Question 2.
Secretin stimulates secretion of ………. and ……….
Answer:
water, bicarbonate ions

Question 3.
………… (CCK/GIP) inhibits gastric secretion and motility.
Answer:
AGIP

Question 4.
Hormones bind to the specific proteins, i.e., ………… to produce their effects on target tissues.
Answer:
Hormone receptor

Question 5.
Where are the hormone receptors present?
Answer:
Target tissues

Question 6.
………… receptors are present inside the target cell.
Answer:
Intracellular

Question 7.
Give a common biological terms for the following groups on the basis of chemical nature of hormones.
i) Melatonin, Catecholamines, Adrenaline, Nor-adrenaline
ii) ADH, Oxytocin, ACTH, Calcitonin
iii) Insulin, Glucagon, Parathyroid, Relaxin
Answer:
i) Amines
ii) Peptides
iii) Proteins

Question 8.
Name the substance, that integrates and co-ordinates all the metabolic activities within the organism.
Answer:
Hormones

Question 9.
The ………… and the ………… system jointly coordinate and regulate the physiological functions in the body,
Answer:
Neural system, endocrine

Question 10.
Endocrine glands are also known as ………… glands.
Answer:
Ductless

Question 11.
Name the chemical which is non-nutrient, acts as intercellular messenger and is produced in trace amount.
Answer:
Hormone

Question 12.
The ………… and ………… producing diffused tissues/cells located in different parts of our body constitute the endocrine system.
Answer:
Endocrine glands, hormone

Question 13.
The atrial wall of our heart secretes a peptide hormone called …………
Answer:
Atrial Natriuretic Factor (ANF)

III. One Word Answer Questions (1 Mark )

Question 1.
Name the hormones which are secreted from gastro-intestinal tract.
Answer:
Gastrin, secretin, cholecystokinin (CCK) and Gastric Inhibitory peptide (GIP).

Question 2.
Hormones which interact with membrane bound receptors, generate enzymes.
Answer:
Second messengers.

Question 3.
Name any four organs other than endocrine system that produce hormones
Answer:
Gastro intestinal tract, liver, kidney and heart.

AP 9th Class Physics Bit Bank Pdf Download in Telugu & English Medium

• Chapter 1 Matter in Our Surroundings Class 9 MCQ
• Chapter 2 Is Matter Around Us Pure Class 9 MCQ
• Chapter 3 Atoms and Molecules Class 9 MCQ
• Chapter 4 Structure of the Atom Class 9 MCQ
• Chapter 7 Motion Class 9 MCQ
• Chapter 8 Force and Laws of Motion Class 9 MCQ
• Chapter 9 Gravitation Class 9 MCQ
• Chapter 10 Work and Energy Class 9 MCQ
• Chapter 11 Sound Class 9 MCQ
• Chapter 5 The Fundamental Unit of Life Class 9 MCQ
• Chapter 6 Tissues Class 9 MCQ
• Chapter 12 Improvement in Food Resources Class 9 MCQ

Also Read

• AP Board Solutions Class 9
• AP Board Solutions Class 9 Physics (Physical Science)
• AP 9th Class Physics Important Questions
• AP 9th Class Physical Science Notes

AP Bit Bank

AP Board 9th Class Physics Notes

• Chapter 1 Matter in Our Surroundings Class 9 Notes
• Chapter 2 Is Matter Around Us Pure Class 9 Notes
• Chapter 3 Atoms and Molecules Class 9 Notes
• Chapter 4 Structure of the Atom Class 9 Notes
• Chapter 7 Motion Class 9 Notes
• Chapter 8 Force and Laws of Motion Class 9 Notes
• Chapter 9 Gravitation Class 9 Notes
• Chapter 5 The Fundamental Unit of Life Class 9 Notes
• Chapter 6 Tissues Class 9 Notes
• Chapter 12 Improvement in Food Resources Class 9 Notes

Also Read

• AP Board Solutions Class 9
• AP Board Solutions Class 9 Physics (Physical Science)
• AP 9th Class Physics Important Questions
• AP 9th Class Physical Science Bit Bank

AP Board Notes

AP State Board new syllabus AP Board Solutions Class 9 Biology 12th Lesson Improvement in Food Resources Questions and Answers.

Biology 9th Class 12th Lesson Questions and Answers Improvement in Food Resources

9th Class Biology 12th Lesson Improvement in Food Resources Questions and Answers (Exercise)

Question 1.
Explain any one method of crop production which ensures high yield.
Answer:
i) One method used for crop production which ensures high yield is hybridisation.
ii) It is the science involved in improving the varieties of crops by breeding plants.
iii) The plants from different areas is picked up with desired traits and hybridisation or cross – breeding of these varieties is done to obtain a plant/crop of desired characteristic.
iv) The high yielding crop variety shows the following characteristics :

• High yield
• Early meturation, less water for irrigation, better quality seeds are produced, less fertilisers required, adapts itself to the environmental conditions.

Question 2.
Why are manure and fertilisers used in fields ?
Answer:
They are used to ensure good vegetative growth giving rise to healthy plants, that results in high crop production.

Question 3.
What are the advantages of inter-cropping and crop rotation ?
Answer:
Advantages of using inter-cropping:

• It helps to maintain soil fertility.
• It increases productivity per unit area
• Save labour and time
• Both crops can be easily harvested and processed separately.

Advantages of using crop rotation:

• It improves the soil fertility.
• It avoids depletion of a particular nutrient from soil.
•  It minimise pest infestation and diseases.
• It helps in weed control.
• It prevents change in the chemical nature of the soil.

Question 4.
What is genetic manipulation? How is it useful in agricultural practices ?
Answer:
Genetic manipulation is a process of incorporating desirable characters into crop varieties by hybridisation. Hybridisation involves crossing between genetically dissimilar plants. This is done for production of varieties with desirable characteristics like profuse branching in fodder crops, high yielding variaties in maize, wheat etc.

Genetic manipulation is useful in developing varieties which shows :

• increased yield
• better quality
• shorter and early mature peiod
• Better adaptability to adverse environmental condition
• Desirable characteristics.

Question 5.
How do storage grains losses occur ?
Answer:
The factors responsible for loss of grains during storage are :

• Abiotic factors like mositure, humility and temperature.
• Biotic factors like insects, rodents, birds, mites and bacteria.

Question 6.
How do good animal husbandry practices benefft farmers ?
Answer:
Good animal husbandry practices are beneficial to the farmers in the following ways :

• Improvement of breeds of the domesticated animals.
• Increasing the yield of food stuffs such as milk, eggs and meat.
• Proper management of domestic animals interms of shelter, feeding, care and protection against diseases.-

These ways help the farmers to improve their economic condition.

Question 7.
What are the benefits of cattle farming ?
Answer:
Cattle farming is beneficial in the following ways :

• Milk production is increased by high yielding animals.
• Good quality of meat, fibre and skin can be obtained.
• Good breed of draught animals can be obtained.

Question 8.
For increasing production, what is common in poultry, fisheries, and bee – keeping.
Answer:
Through cross breeding, the production of poultry, fisheries and bee keeping can be increased.

Question 9.
How do you differentiate between capture fishing, mari culture and aqua culture ?
Answer:

Capture fishing	Mari culture	Aqua cultrue
It is the fishing in which fishes are captured from natural resources like pond, sea water and estuaries.	It is the culture of fish in marine water varieties like prawns, oysters, bhetki, and mullets are cultured for fishing.	It is done both in fresh water and in marine water.

9th Class Biology 12th Lesson Questions and Answers (InText)

Question 1.
What do we get from cereals, pulses, fruits and vegetables?
Answer:

• The cereals provide us with carbohydrates.
• The pulses provide us with proteins.
• Fruits and vegetables give us carbohydrates, protein, fat, vitamins, minerals and lots of fibers.

Question 2.
How do biotic and abiotic factors affect crop production ?
Answer:
Two major factors that affect the crop are Biotic factors like insects, rodents, pests and many more spread the disease and reduce crop production. Abiotic factors like humidity, temperature, moisture, wind, rain, flood and many more destroy the crop raised.

Question 3.
What are the desirable agronomic characteristics for crop improvements ?
Answer:

• Crops with high nutritional content.
• Plants that are highly resistant to diseases and pests.
• The yield of the crop has to be high.
• Tallness and profax branching are desirable characteristics for fodder crops.

Question 4.
What are macro-nutrients and why are they called macro-nutrients?
Answer:
The nutrients which require in large quantities are called macro-nutrients. They provide good yield. Hence they are called like that.

Question 5.
How do plants get nutrients?
Answer:
Plants get nutrients from manure which supplies nutrients to soil.

Question 6.
Compare the use of manure and fertilizers in maintaining soil fertility.
Answer:

• Manure improves soil quality with added nutrients.
• Manure provides extra organic matter called humus to the soil therefore increasing the water retention capacity of sandy soils and drainage in clayey soil.
• Manures reduces soil erosion.

Effects of fertilisers :

• Fertilisers makes the soil become too dry and powdered and rises the rate of soil erosion.
• The nature of soil changes either too basic or acidic.

Question 7.
Which of the following conditions will give the most benefits ? Why ?
a) Farmers use high-quality seeds do not adopt irrigation or use fertilizers.
b) Farmers use ordinary seeds adopt irrigation and use fertilizer.
c) Farmers use quality seeds, adopt irrigation, use fertilizer and use crop production measures.
Answer:

• The condition (c) will give most benefits.
• Farmers will get the most benefit because the use of fertilisers make the soil enriched with micro & macro nutrients and good quality seeds led to a better yield crops.

Question 8.
Why should preventive measures and biological control methods be preferred for protecting crops?
Answer:

• Preventive measures and biological control methods should be prepared for protecting crops because these methods are safe ecologically and do not harm other life forms.
• Biological control methods involve the use of biological organisms and hence these are completely safe for other life forms.

Question 9.
What factors may be responsible for losses of grains during storage ?
Answer:
Abiotic factors :
i) Moisture, humidity (in the air) and temperature are abiotic variables that are responsible for losses of grain during storage.
Biotic factors :
Insects, rats, birds, mites, bacteria and fungi are biotic forces that are responsible for the lossess of grain during storage.

Question 10.
Which method is commonly used for improving cattle breeds and why ?
Answer:
The method of cross-breeding is widely used to improve cattle breeds. Cross breeding to good cattle varieties will lead to a new, improved variety.

Question 11.
Discuss the implications of the following statement:
“It is interesting to note that poultry is India’s most efficient converter of low fibre food stuff (which is unfit for human consumption) into highly nutritious animal protein food.”
Answer:

• Poultry farming is the practice of farming of fowls for the production of eggs and meat.
• The fowls that are reared in the poultry farms are fed with the left over fibres from the cereals that are left after the grains are removed.
• These are low fibre food that the fowl intake to grow and they produce the eggs and meat finally.
• Therefore by feeding them the low fibre food that human’s generally do not intake, they are providing the highly nutritious animal protein food in the form of meat and eggs.

Question 12.
What management practices are common in dairy and poultry farming ?
Answer:

• A shelter that is both clean and adequate.
• Provision of hygenic and nutritionally adequate food.
• A well ventilated and open, airy place for their development.
• Prevention of sickness and disease-causing pathogens from infection them.

Question 13.
What are the differences between broilers and layers and in their management ?
Answer:
Broilers do not require much space and lighting. Layers need enough space and lighting. They need protein rich food and sufficient fat food as broilers have fast growth rates.

Question 14.
What are the desirable characters of bee varieties suitable for honey production ?
Answer:

• A big proportion of honey and wax should be produced and collected by the bees.
• Bees should reside in a hire for long duration.
• The bees should be able to reproduce well.
• The bees must not sting.

Question 15.
What is pasturage and how is it related to honey production?
Answer:

• Pasturage refers to the plants from which bees can collect pollen and nectar.
• Nectar producing plants are Tamarind, Neem etc.
• Pollen producing plants are roses, sorghum, maize etc. Plants that produce both nectar and pollen are apples, bananas, sunflowers etc.

Question 16.
How are fish obtained ?
Answer:
Fishes are obtained in two methods.

• Capturing fish
• Fish culture

Question 17.
What are the advantages of composite fish culture ?
Answer:
An advantage of composite fish culture is that it increases the yield of fish nearly 5-6 different species are grown together in single pond.

9th Class Biology Chapter 12 Questions and Answers (Lab Activities)

(Page No. 60)

Question 1.
Visit a near by garden / agricultural field and make a list of the weeds and the flowers / crops found in the area. Also make a list of insect pests, if any infesting the flowers / crops.
Answer:
I visited near by garden & I made a list of weeds & insect pests.

List of weeds :

• Poison Sumac
• Japanese knot weed
• Crab grass
• Dandelions
• Common Rag weed
• Plantain plants
• Giant Rag weed
• Ground Ivy
• Clover leaf
• Chickweed etc.

List of insect pests

• Scales
• Thrips
• Aphids
• Mealy bugs
• White flies
• Spider mites
• Caterpillars
• Grasshopper
• Weevils etc.

(Page No. 60)

Question 2.
Collect grains / seeds of cereals / pulses and oil seeds and gather information about the seasons in which they are sown and harvested?
Answer:

Name of the grains / pulses	Season
Wheat	Rabi
Barley	Rabi
Pea	Rabi
Gram	Rabi

 

Name of the grains/pulses	Season
Rice Maize Jowar Moong Seasonal fruits Vegetables	Kharif Kharif Kharif Kharif Zaid Zaid

(Page No. 62)

Question 3.
Visit a livestock farm. Note the following :
i) Number of cattle and number of different breeds.
ii) The amount of daily milk production from the different breeds.
Answer:
I visited a near livestock farm. I noted the following list :

Name of the breed	Production of milk (Daily)
l) Milch Breed	10 liters
2) Holestain Friesian	30 lit.
3) Jersey	20 lit.
4) Red Sindhi cow	20 lit.
5) Gir cow	25 lit.
6) Rathi cow	20 lit.

(Page No. 64)

Question 4.
Visit a local poultry farm. Observe types of breeds and note the type of ration, housing and lighting facilities given to them. Identify the growers, layers and broil­ers.
Answer:
I visited Bindu’s Hatcheries pvt.Ltd., at Vijayawada. There I observed so many types of broilers, Growers, Layers. Aseel, Frizzle, Kadaknath, Naked neck etc are the native breeds. The manager of hatcheries explained about the types of ration such as chick starter, Grower feed, Layer feed, Flock raiser, Broiler feed, Game bird feed, Fermented feed cracked corn, etc.,

Asst, manager said about the different types of poultry houses such as Brooder / Chick house, Grower house, Layer house, Broiler’s house, Environmentally controlled house, etc to protect the birds from adverse climatic conditions.

They provided the lighting in this way i.e., light at 7-8 feet above the ground level and he said that it must be hanged from ceiling. If incandescent bulbs are used, the interval between two bulbs is 10 feed. In case of flourascent lights the interval is 15 feet.

I found Aseel, Busra, Danti, Giriraja, Kadaknath, Kalasthi, Nicobari, Punjab Brown, Vanaraja etc in the hatchery.

(Page No. 68)

Question 5.
Visit a fish farm in fish breeding season and note the following:
1. Varieties of fish in fish farm
2. Types of ponds
3. Feed ingredients used
4. Production capacity of the farm
If there are no fish farms close to your locality, gather the above information from Internet, by referring books or talking to people who are engaged in fishery.
Answer:
I visited “Sneha’s fish farm at near by my village.
I saw Anabas, Tilapia, Rohu, Mrigal and Catla varieties of fishes in the farm. The manager said they constructed the ponds by two types namely, dug out and embank­ment pond.

The dug out pond is constructed by digging the soil and is most suitable to construct ponds in plain areas. Regarding feeding, the manager explained that they give three types of food. They are natural, food, supplementary feeds, complete feeds etc.

Natural food found naturally in the pond. It may include detritus, bacteria, plank­ton, worms, insects, snails, aquatic plants and fish. Supplementary feeds are the kitchen wastes or agricultural by products. Complete feeds are the feeds made from a mixture of carefully fleeted ingredients to provide all the nutrients necessary for the fish to grow well.

AP State Board new syllabus AP Board Solutions Class 9 Biology 6th Lesson Tissues Questions and Answers.

Biology 9th Class 6th Lesson Questions and Answers Tissues

9th Class Biology 6th Lesson Tissues Questions and Answers (Exercise)

Question 1.
Do plants and animals have the same structure? Do they both perform similar functions?
Answer:

• Plants and animals have different types of structure and function.
• Though the basic functions show similarity, yet the functions are different from each other.

Question 2.
Can we think why meristematic tissue would lack vacuoles ?
Answer:
Since meristems are young cells and actively dividing, they do not participate actively in food preparation. Also they do not produce a large amount of waste. Hence they lack vacuoles.

Question 3.
What happens to the cells formed by meristematic tissue?
Answer:

• Cells of a meristematic tissue can either continue to divide and remain as meristematic.
• They may also differentiate and lose their ability to divide and form permanent tissues.

Question 4.
In some plants like desert plants, epidermis has a thick waxy coating of cutin on its outer surface. Can we think of a reason for this ?
Answer:

• A thick, waxy coating of cutin is present on the epidermis of desert plants.
• It helps in reducing the loss of water in desert plants.
• Suberin which also a chemical, is present in the walls of dead cork cells. It makes these cells impervious to gases and water.

Question 5.
Is the outer layer of a branch of a tree different from the outer layer of a young stem?
Answer:

• The outer most layer of the trees is covered by the bark.
• It gives strength and protects the plant from injury and infections.
• The bark is made up of dead cells from different origins like cork, phelloderm, cortex, phloem, and xylem.
• The outer layer of the young stem is made up of living cells.

Question 6.

In Fig 6.3 showing a section of stem, can you see different types of cells in the vascular bundle?
Answer:
Yes, we can see different types of cells in the vascular bundle.

Question 7.
When we breathe we can actually feel the movement of our chest. How do these body parts move?
Answer:
These body parts move by the specialised cells called muscle cells.

Question 8.
During breathing we inhale oxygen. Where does this oxygen go ?
Answer:
It is absorbed in the lungs and then is transported to all the body cells through blood.

Question 9.
Why would cells need oxygen?
Answer:

• Oxygen helps organisms grow, reproduce, and turn food into energy.
• Humans get the oxygen they need by breathing through their nose and mouth into their lungs.
• Oxygen gives our cells the ability to breakdown food in order to get the energy we need to survive.

Question 10.
What would be the advantage of strong and nonflexible properties for bone functions?
Answer:
Strong and non = flexible characteristic of bones provide shape to the body and skeletal support.

Question 11.
They are also called unstriated muscles? Why would they be called that ?
Answer:
Smooth muscles are called unstriated muscles because these muscles show no cross striations and look smooth.

9th Class Biology 6th Lesson Questions and Answers (InText)

Question 1.
What is a tissue?
Answer:
A tissue is defined as a cluster of cells which are similar in structure and work together to perform a particular function.

Question 2.
What is the utility of tissues in multicellular organisms ?
Answer:
The use of tissues in multicellular organisms is to provide structural and mechanical strength as well as to allow division of labour.

Question 3.
Name the types of simple tissues.
Answer:
The types of simple tissues are :

• Parenchyma
• Collenchyma
• Sclerenchyma

Question 4.
Where is apical meristem found ?
Answer:
In plants, apical meristem is typically found at

• the tip of the shoot
• root of the plant

Question 5.
Which tissue makes up the husk of coconut?
Answer:

• The sclerenchyma tissue, which is a type of permanent tissue makes up the husk of coconut.
• These tissue causes the plant become stiff and hard.
• The cells of this tissue are dead and their cell walls are thickened because of the presence of lignin.

Question 6.
What are the constituents of phloem?
Answer:
The phloem constitutes of the following four elements they are :

• Sieve tube
• Companion cells
• Phloem parenchyma
• Phloem fibres

Question 7.
Name the tissue responsible for movement of our body.
Answer:
Two tissues jointly are responsible for the movement of our body namely –

• Muscular tissue
• Nervous tissue

Question 8.
What does a Neuron look like ?
Answer:

• A Neuron is a Nerve cell comprising the cell body with a nucleus and cytoplasm from which a long and thin hair like structure emerges.
• Every neuron has one elongated part known as the -axon, and several short and small branched structures known as dendrites.
  
• A single neuron can even be a meter long.

Question 9.
Give three features of cardiac muscles.
Answer:
a) Cardiac muscles are specialised tissues that are evolved to pump blood through out the body.
b) The following are the features of cardiac muscles :

• They are cylindrical in shape.
• Striated muscle fibres.
• They are uninucleated and branched.
• These muscles are involuntary in nature.

Question 10.
What are the functions of areolar tissue?
Answer:

• Areolar tissues are typically obşerved in animals.
• They are connective tissues and are found in between skin and muscles.
• They are also located around blood vessels and nerves, and are present in the bone marrow.
• The space inside the organs is filled with these tissues.
• They support the delicate internal organs and assist in tissue repair in case of damage.

9th Class Biology Chapter 6 Questions and Answers (Lab Activities)

(Page No. 26)

Aim : To observe the growth of roots in onion bulbs.
Things required : Two glass jars, onion bulbs, water, blade.

Procedure :

• Take two glass jars and filled them with water.
• Now take two onion bulbs and placed one on each jar, as shown in figure.
• Observe the growth of roots for 3 days.
• On the 4th day, I cut the root tips of the inion bulb in jar 2 by about 1 cm.
• Observation : The growth of roots in both the jars and measure their lengths each
  day for five more days and record the observations in given tables :

Length	Day 1	Day 2	Day 3	Day 4	Day 5
Jar 1	2.0 cm	3.0 cm	3.5 cm	4.0 cm	4.5 cm
Jar 2	2.0 cm	2.0 cm	2.0 cm	2.0 cn	2.0 cm

And answer the following questions after observation.

Observation :

Question 1.
Which of the two onions has longer roots ?
Answer:
Onion in Jar-1 has longer roots because they keep on growing due to the presence of apical meristem in root tip.

Question 2.
Do the roots continue growing even after we have removed their tips ?
Answer:
No, the roots do not continued growing even after we have removed their tips.

Question 3.
Why would the tips stop growing in Jar-2 after we cut them?
Answer:
The tips stopped growing because the meristematic tissue not available there. Inference :
The growth of the plants occurs only in certain specific regions. This is because of the dividing tissue, meristematic tissue.

(Page No. 28)

Aim: To observe section of a stem.
Things required: Plant stem, Blade, slide, Coverslip, Saffranin, Glycerine microscope.
Procedure :

• Take a plant stem and with the help of your teacher cut into very thin slices or sections.
• Stain the slices with safranin and placed one neat section on a slide, and put a drop of glycerine.
• Cover it with a coverslip and observe the various types of cells and their arrangement and answer the questions.

Observation :

Question 1.
Are all cells similar in structure?
Answer:
No, all cells are not similar in structure.

Question 2.
How many types of cells can be seen ?
Answer:
6 types of cells can be seen.

Question 3.
Can we think of reasons why there would be so many types of cells?
Answer:
Yes, to perform different types of functions, there would be so many types of cells.

(Page No. 30)

Aim : To observe the Guard cells and epidermal cells in epidermis.
Things required :
Rheo leaf, blade, needle, slide, water, safranin, coverslip, microscope.

Procedure :

• Take a freshly plucked leaf of Rheo.
• Stretch and broke it by applying pressure.
• Remove the peel and put it in a petridish filled with water.
• Add few drops of safranin.
• Wait for a couple of minutes and then transfer it on to a slide and gently place a coverslip over it.
• Observe it under a microscope.

Observation :
Answer:
I observed that there is an outermost layer of cells and some stomata, guard cells.
Inference :
The outermost layer of cells is called epidermis and it contains so many organelles such stomata, guard cells etc.

(Page No. 36)

Take a drop of blood on a slide and observe different cells present in it under a microscope.
Answer:
Aim : To observe the blood and its types.
Things required : Adrop of blood, slide, cover slip, microscope, a needle.

Procedure :

• Collect a drop of blood with the help of a needle.
• Put it on the slide and cover it with a coverslip.
• Observe under a microscope.

Observation :
I found different types of cells in the fluid called blood.

Inference :
Blood has a liquid matrix called plasma, in which red blood corpuscles, white blood corpuscles and platelets are suspended.

(Page No. 36)

Compare the structures of different types of muscular tissues. Note down their shape, number of neuclei and position of nuclei within the cell in table 6.1.
Answer:
Aim : To observe shape, number of nuclei and its position in different types of muscles.
Things required : Permanent slides of muscle cells, Microscope.

Procedure :

• Take different types muscles permanent slide i.e., striated, smooth, cardiac muscles etc.
• Observation each slide one by one and note down in the table below.

Observation :

AP State Board new syllabus AP Board Solutions Class 9 Biology 5th Lesson The Fundamental Unit of Life Questions and Answers.

Biology 9th Class 5th Lesson Questions and Answers The Fundamental Unit of Life

9th Class Biology 5th Lesson The Fundamental Unit of Life Questions and Answers (Exercise)

Question 1.
Make a comparison and write down ways in which plant cells are different from animal cells.
Answer:
Differences between a plant ceil and an animal cell.

Plant cell	Animal cell
1) Plant cells have cell wall.	1) Animal cells don’t have a cell wall
2) They contain chloroplast.	2) They don’t have ehloroplasts.
3) They do not have centriole.	3) Centriole is present in them.
4) Vacuole is large and present in centre of the cell.	4) Vacuole is small.
5) Nucleus is present in the side of the plant cell.	5) Nucleus is present in the centre of the animal cell.

Question 2.
How is a Prokaryotic cell different from a Eukaryotic cell ?
Answer:

Prokaryotic cell	Eukaryotic cell
1) Size : Generally small (1 -10μm) 1μm pm = 10-6 m	1) Size : Generally large (5 -100 pm)
2) Nuclear region is poorly defined due to absence of a nuclear membrane and known as nucleoid.	2) Nuclear region is well defined and surrounded by a nuclear membrane
3) There is a single chromosome.	3) There are more than one chromosomes.
4) Membrane bound cell organelles absent.	4) Membrane bound cell organelles present.

Question 3.
What would happen if the plasma membrane ruptures or breaks down?
Answer:
If plasma membrane ruptures or breaks down then molecules of some substances will freely move in and out.

Question 4.
What would happen to the life of a cell if there was no Golgi apparatus ?
Answer:
If there were no Golgi bodies, packaging and dispatching of materials synthesised by the cell will be stocked.

Question 5.
Which organelle is known as the powerhouse of the cell ? Why?
Answer:
Mitochondria is known as the ‘Power House’ of the cell because it stores the energy in the form of ATP, it releases the energy to the cell whenever it requires to perform different activities of life.

Question 6.
Where do the lipids and proteins constituting the cell membrane get synthesised?
Answer:
Lipids and proteins constituting the cell membrane synthesized in Endoplasmic Reticulum.

Question 7.
How does Amoeba obtain its food ?
Answer:

• Through the process of endocytosis, an amoeba obtains its food.
• As its cell membrane is flexible enough, food particles are engulfed, forming a food vacuole girdling it, which is assisted by the pseudopodia.
• Amoeba secretes digestive enzymes to bring about digestion of the engulfed partide once the food is trapped.

Question 8.
What is osmosis ?
Answer:
The process of movement of water molecule from a region of higher concentration to a region of lower concentration through a semipermeable ’membranes is known as Osmosis.

Question 9.
Carry out the following osmosis experiment.
Take four peeled potato halves and scoops each one out to piake potato cups. One of these potato cups should be made from a boiled potato. Put each potato cup in a trough containing water. Now,
a) keep cup empty
b) put one teaspoon sugar in cup B
c) put one teaspoon salt in cup C
d) put one teaspoon sugar in the boiled potato cup D.
Keep these for two hours. Then observe the four potato cups and answer the following.
i) Explain why water gathers in the hollowed portion of B and C.
ii) Why is potato A necessary for this experiment ?
iii) Explain why water does not gather in the hollowed out portions of A and D.
Answer:
i) Water accumulates in the hollowed portions of B and C as a difference in the water concentration is observed. There by endosmosis occurs as the cells acts as semi- permeable membrane.

ii) Potato A is essential in this experiment as it is significant to compare different scenarios seen in potato cups B, C and D. A in this experiment clearly shows that the potato cavity on its own cannot bring about water movement.

iii) Cup in A does not show any change in the water flow concentration for osmosis to occur which requires concentration to be higher than the other. Cells in cup D are dead, thus there is no existence of a semipermeable membrane for water flow. Consequently osmosis does not occur.

Question 16.
Which type of cell division is required for growth and repair of body and which type is involved in the formation of gametes ?
Answer:
There are two ways in which a ceH divides :

• Mitosis
• Meiosis

Mitosis is the type of cell division that is involved in the growth and repair of the body, whereas meiosis is a type of cell division which results in the formation of gametes.

9th Class Biology 5th Lesson Questions and Answers (InText)

Page No. 6

Question 1.
Who discovered cells and how ?
Answer:

• Robert Hooke discovered cells in 1665.
• While examining thin slice of cork through a self designed microscope.
• He saw that cork resemble the structure of a honey comb comprises many little compartments.
• These small boxes are called cells.

Question 2.
Why is the cell called the structural and functional unit of life?
Answer:

• Cells form the structure of an entity. . .
• A group of cells form a tissue, further an organ and ultimately an organ system.
• They perform fundamental functions and life processes such as respiration, digest­ing, excretion etc., in the unicellular and multicellular organisms. They perform all the activities independently.
• Hence cells are referred to as structural and fundamental units of life.

Page No. 10.

Question 1.
How do substances like CO₂ and water move in and out of the cell ? Discuss.
Answer:
a) CO₂ moves by diffusion.

• The cellular waste accumulates in high concentration in the cell, whereas the . ‘ concentration of CO₂ in the external surrounds is comparatively lower.
• This difference in the concentration level inside and out side of the cell causes the CO₂ to diffuse from a region of higher (within the cell) to a lower concentration.

b)

• Water diffuses by osmosis through the cell membrane.
• It moves from a region of higher concentration to a lower concentrated region through a selectively permeable membrane until equilibrium is reached.

Question 2.
Why is the plasma membrane called a selectively permeable membrane ?
Answer:

• The plasma membrane allows or permits the entry and exit of some materials in and out of the cell.
• It also prevents the movement of some other materials. Hence plasma membrane is called a selectively permeable membrane.

Page No. 14.

Question 1.
Fill in the gaps in the following table illustrating differences between Prokaryotic and Eukaryotic cells.

Prokaryotic cell	Eukaryotic cell
1) Size : Generally small (1-10 pm) lpm=l0″6m	1) Size : Generally large (5-100 pm)
2) Nuclear region : ……….. and  known as ………	2) Nuclear region : well defined and surrounded by a nuclear membrane.
3) Chromosome: single	3) More than one chromosome.
4) Membrane bound cell organelles are absent	4) ……………………………. …………………………….

Answer:
2) Nuclear region : Poorly defined and due to absence of nuclear membrane is called Nucleoid.
4) Membrane bound cell organelles are present.

Question 1.
Can you name the two organelles we have studied that contain their own genetic material?
Answer:
Mitochondria and Plastids have their own DNA and ribosomes.

Question 2.
If the organisation of a cell is destroyed due to some physical or chemical influence, What will happen ?
Answer:
If the organisation of a cell is destroyed due to some physical or chemical influence, the cell will not be able to perform the basic functions.

Question 3.
Why are lysosomes known as suicide bags ?
Answer:

• When foreign materials entering the cell, such as bacteria, or food as well as old organelles end up in lysosomes, which break complex substances into simpler
  sub-stances as they contain digestive juices.
• When the cell gets damaged, lysosomes may burst and the enzymes digest their own cell. Therefore, lysosomes are also called as suicide bags of cell.

Question 4.
Where are proteins synthesised inside the cell ?
Answer:
Endoplasmic reticulum synthesise proteins inside the cell.

Page No. 4

Question 1.
Can we find out names of some more unicellular organisms.
Answer:
Yes. Euglena, Vorticella

Question 2.
Every multi-cellular organism has come from single cell. How ?
Answer:
Yes. According to the cell theory, all cells arise from pre-existing cells, that means every cell divides and form new cells.

Page No. 6

Question 3.
How does a living cell perform these basic functions?
Answer:
Living cell performs these basic functions as it comprises many cell organelles in it. Each kind of cell organells perform a special function. Because of these organelles cell performs all functions. So cell is called a basic unit and functional unit of life.

Question 4.
How is a cell organised ?
Answer:
Cell is made up of some special components called organelles.

Question 5.
How does the movement of substances take place into the cell? How do substances move out of the cell ?
Answer:
The movement of substances take place in by a process called diffusion. Substances move out of cell by a process called diffusion.

Page No. 8

Question 6.
What will happen if we put an animal cell or plant cell into a solution of sugar or salt in water?
Answer:

• If the medium surrounding the cell has a higher water concentration than the cell, meaning that the outside solution is very dilute, the cell will gain the water by osmosis. The cell is likely to ‘swell up’.
• If the medium has exactly the same water concentration as the cell, there will be no net movement of water across the cell membrane. The cell will stay the “same size”.
• If the medium has a lower concentration of water than the cell, meaning that it is a very concentrated solution, the cell will lose water by osmosis. Then the cell will “shrink”.

Page No. 10

Question 7.
Remember the temporary mount of onion peel we prepared we had put iodine solution on the peel. Why ?
Answer:
To get the parts cleary visible.

Question 8.
What would we see if we tried observing the peel without putting the iodine solution?
Answer:
We will be unable to get clear vision of the parts.

Question 9.
Further, when we put iodine solution on the peel, did each cell get evenly coloured?
Answer:
No, some parts of the peel only get coloured.

9th Class Biology Chapter 5 Questions and Answers (Lab Activities)

(Page No. 2)

Question 1.
How do you observe cells in onion peel under microscope ? Write your observations.
Answer:
Aim : To observe a cell in the onion peel:
Things required: Onion bulb, onion peel, watch – glass, water, slide, camel hair brush, safranin, coverslip, needle, forceps microscope.

Procedure:

• I took a onion peel from a onion bulb with the help of a forceps.
• Immediately I put it in a watch glass containing water to keep it wet.
• Now I took a glass slide and I put a drop of water on it.
• I transferred a small piece of the feet from the watch glass to the slide perfectly flat with the help of a camel hair brush.
• I put a safranin solution on the peel followed by a coverslip by avoiding air bubbles.
• And I observed the slide under low power followed by high powers of a compound
  microscope.

Observation : I observed a small room like structure in the onion peel.
Inference : The small room like structures are called “cell”

(Page No. 4)

Question 2.
We can try preparing temporary mounts of leaf peels, tip of roots of onion or even peels of onions of different sizes.
After performing the above activity, let us see what the answers to the following questions would be:
a) Do all cells look allke in terms of shape and size?
b) Do all cells look alike in structure?
c) Could we find differences among cells from different parts of a plant body?
d) What similarities could we find?
Answer:
Aim : To prepare the temporary mounts of leaf peels.
Things required : Microscope, different types of leaves, root tips of onion, different sizes of onions, slide, cover slip, safranin, blade.
Procedure :

• I took some onions, Raheo leaf and took a peel from them with help of a blade, or a forceps.
• I put them in a watch – glass containing water.
• I transferred them to the slide containing a drop of water and I added some safranin solution them.
• I put a cover slip on the slide without bubbles. My temporary mounts are ready and I observed under a microscope.

Observation : I observed different sizes and shapes of cells.
Inference : The cells are of different sizes and shapes.

Activity Based Questions :

1. Do all cells look alike in terms of shape and size ?
Answer: No, All cells do not look alike in terms of shape and size.

2. Do all cells fook alike in structure ?
Answer: No, All cells do not look alike in structure.

3. Could we find differences among cells from different parts of plant body ?
Answer: Yes, we find differences among cells from different parts of the plant body.

4. What similarities could we find ?
Answer: We get similarities in the parts of the plant body.

(Page No. 8)

Question 3.
Write an experiement with an egg to prove osmosis.
Answer:
Aim : To know the process of osmosis.
Things required : Egg, Dilute HCl, pure water, salt
Procedure :

• I took an egg and removed the shell of the egg by dissolving it in dilute hydrochloric acid.
• A thin outer skin encloses the egg is left over.
• I put the egg in pure water in a beaker and observed.
• I placed a similar deshelled egg in a concentrated salt solution and I observed for 5 minutes.

Observation :
a) The egg swells because water passes into it by osmosis.
b) The egg shrinked, water passes out of the egg solution into the salt solution because the salt solution is more concentrated.
Inference : Exosmosis and endosmosis occured in both conditions.

(Page No. 8)

Question 4.
Write an activity to prove osmosis with dried raisins or apricots.
Answer:
Aim : To observe the process of osmosis in Raisins.
Things required : Dried Raisins/Apricots, water, sugar/salt solution, bowls.

Procedure :

• I took some dried raisins or apricots and put in plain water in a bowl and observed.
• I took some dried raisins and put in a bowl contained concentrated solution of sugar or salt.

Observation :
a) Each raisins gained water and swelled up when placed in water.
b) When I placed them in the concentrated solution, it loses water, consequently shrinks.
Inference : In the plant cells also osmosis occur (Endosmosis & Exosmosis)

(Page No. 10)

Question 5.
Find out about electron microscopes from resources in the school library or through the internet. Discuss it with your teacher.
Answer:
1) An electron microscope is a microscope that uses of beam of electrons as a source of illumination.

2) They use electron optics that are analogous to the glass lenses of an optical light microscope. As the wavelength of an electron can be up to 100,000 times shorter than that of visible light, electron microscopes have a higher resolution of about 0.1 mn, which compares to about 200 nm for light microscopes. These are expensive to build and maintain.

Question 6.
How do you prove that only living cells and not dead cells are able to absorb water by osmosis ?
Answer:
Aim : To observe plasmolysis
Things required : Rheo leaf; water, microscope, strong solution of sugar or salt.

Procedure :

• I mounted the peel of a Rheo leaf in water on a slide and examined under the high power of a microscope.
• I found some small green granules called chloroplasts which contain green substance called chlorophyll.
• I put a drop of strong solution of sugar or salt on the mounted leaf on the slide. I observed under a microscope after one minute.

Observation : I observed that sugar solution entered into the cells and swells up through osmosis.

B)

• Now I placed some Rheo leaves in boiling water for a few minutes.
• This killed the cells.
• Then mounted one leaf on a slide and observed it under a microscope.
• After that I put a drop of strong sugar solution on the mounted leaf on the slide and I observed.
• No, plasmolysis not occured.

Inference : It appears that only living cells, and not dead cells, are able to absorb water by osmosis.

(Page No. 10)

Question 7.
How do you observe human cheek cells in your science laboratory? Draw your observations.
Answer:
Aim : To observe the nucleus in a cheek cell.
Things required : Slide, Microscope, Ice cream spoon, water, Brush, Cover slip ; Methylene Blue solution.

Procedure :

• By using an ice – cream spoon gently I scraped the inside surface of the cheek and put it on the glass slide and spreaded it evenly.
• To stain its I put a drop of methylene blue solution on it.
• I observed it under microscope.

Observation : I observed a darkly coloured, spherical or oval, dot like structure near the centre of each cell.
Inference : This structure is called Nucleus.

AP State Board new syllabus AP Board Solutions Class 9 Physics 11th Lesson Sound Questions and Answers.

AP 9th Class Physical Science 11th Lesson Questions and Answers Sound

9th Class Physics 11th Lesson Sound Questions and Answers (Exercise)

Question 1.
What is sound and how is it produced?
Answer:
Sound is a form of energy which produces the sensation of hearing in our ears. Sound is produced by forcing an object to vibrate. In other words, sound is produced by vibrating object.

Question 2.
Describe with the help of a diagram, how compressions and rarefactions are produced in air near a source of sound.
Answer:
1. A vibrating membrane moved back and forth to produce sound.
2. When the membrane pushed forward it pushes the particles of air in front of it.
3. Due to this layers of air get compressed increasing the density of air.
4. This compressed air pushes the layer of air next to it.
5. Creating a compression pulse.

6. After pushing the compression pulse forward the air particles comes to normal.
7. When the membrane pushed back.
8. It drags the layer of air particles towards it.
9. As result density of air reduces.
10. Creating a rarefaction pulse.
11. As the membrane moves to & fro rapidly compression and rarefaction pulse are produced continuously one after the other.
12. When these pulses (energy) reaches the ears the eardrum vibrates.
13. And thus we hear the Sound.

Question 3.
Why is sound wave called a longitudinal wave ?
Answer:
The particles of a medium move along the direction of sound wave that why it is a longitudinal wave.

Question 4.
Which characteristic of the sound helps you to identify your friend by his voice while sitting with others in a dark room ?
Answer:
The characteristic of the sound that helps us to identify our friends voice is – “timbre”. Timbre – quality of voice or music.

Question 5.
Flash and thunder are produced simultaneously. But thunder is heard a few sec­onds after the flash is seen, why ?
Answer:
Lightning travels at 3 x 10⁸ ms^-1 where as the thunder travels in air at 344 ms¹, so thunder is heard slower than lightning.

Question 6.
A person has a hearing range from 20 Hz to 20 kHz. What are the typical wave­lengths of sound waves in air corresponding to these two frequencies ? Take the speed of sound in air as 344 ms^-1
Answer:
i) Sound Frequency o = 20 Hz; Speed of sound v = 344 ms^-1

ii) Frequency υ = 20000 Hz ; Speed of sound v = 344 ms^-1

Question 7.
Two children are at opposite ends of an aluminium rod. One strikes the end of the rod with a stone. Find the ratio of times taken by the sound wave in air and in aluminium to reach the second child.
Answer:
Speed of sound in air (s) = 346 ms^-1
Distance transversed = s x t₁ ⇒ d = 346 t₁ …………… (1)

Speed of sound in aluminium = 6420 ms^-1
Distance transversed = s x t₂ = 6420 t₂     …………… (2)

Distance transversed by soundwave is same.

Question 8.
The frequency of a source of sound is 100 Hz. How many times does it vibrate in a minute ?Answer:
Source of sound frequency = 100 Hz
No. of vibrations in is = 100
No. of vibrations in 1 min = 100 x 60 = 6000
It will vibrate 6000 times in 1 min.

Question 9.
Does sound follow the same laws of reflection as light does ? Explain.
Answer:
Yes, sound and light follows the same laws of reflection.

The direction in which sound is incident and is reflected makes equal angles.
∠i = ∠r

Question 10.
When a sound is reflected from a distant object, an echo is produced. Let the distance between the reflecting surface and the source of sound production remains the same. Do you hear echo sound on a hotter day?
Answer:
If the temperature increases speed of sound increases, this reduces the time duration of sound and its reflection, so no echo is heard.

Question 11.
Give two practical applications of reflection of sound waves.
Answer:
Applications of reflection of Sound Waves :

• Reflection of sound waves are used in sonar.
• It is also use to heartbeat in stethoscope.
• Megaphones, loudspeakers, horns, musical instruments all are use this property.

Question 12.
A stone is dropped from the top of a tower 500 m high into a pond of water at the base of the tower. When is the splash heard at the top?Given, g =10 ms^-2 and speed of sound=340 ms^-1
Answer:
Decent of stone :
Initial velocity u =0 ms^-1; Displacement s=500 m

Acceleration due to gravity g=10 ms^-2

Question 13.
A sound wave travels at a speed of 339 ms^-1. If its wavelength is 1.5 cm. What is the frequency of the wave? Will it be audible?
Answer:
Sound wave : Speed ms^-1
Wavelengty λ = 1.5 cm = \(\frac{1.5}{100}\) =0.015 m
[∵ 1m =100 cm; 1cm= \(\frac{1}{100}\) m

Question 14.
What is reverberation ? How can it be reduced ?
Answer:
The persistence of sound due to repeated reflection and its gradual fading away is called reverberation of sound.
1. Excessive reverberation is highly undesirable to reduce it.
2. Use sound absorbing material like

• compressed fibre board,
• rough plaster (or) draperies,
• cushions that absorb sound.

Question 15.
What is loudness of sound ? What factors does it depend on ?
Answer:
Loudness of sound depends on the amplitude (energy) of the sound wave.
It depends on the following factors:

• Loudness α (Amplitude)²
• Loudness depends on distance,
• It also depends on area of vibrating body.

Question 16.
How is ultrasound used for cleaning ?
Answer:

• The object are put in a tank called ultrasonic vibrator.
• When it is filled with water.
•  It creates vibrations and removes dust particles which are impossible to remove normally. Ex : Greasy machine parts, gold jewellery are cleaned by using this.

Question 17.
Explain how defects in a metal block can be detected using ultrasound.
Answer:
Ultrasonic waves are allowed to pass through the metal block.

• Detectors are used to detect transmitted waves.
• If there is a defect the ultrasound waves get reflected back.
• Indicating the presence of flaw (or) defect.

9th Class PS 11th Lesson Questions and Answers (InText)

Question 1.
How does the sound produced by a vibrating object in a medium reach your ear?
Answer:

• A vibrating membrane moved back and forth to produce sound.
• When the membrane pushed forward it pushes the particles of air in front of it.
• Due to this layers of air get compressed increasing the density of air.
• This compressed air pushes the layer of air next to it.
• Creating a compression pulse.
• After pushing the compression pulse forward the air particles comes to normal.
• When the membrane pushed back.
• It drags the layer of air particles towards it.
• As result density of air reduces.
• Creating a rarefaction pulse.
• As the membrane moves to & fro rapidly compression and rarefaction pulse are produced continuously one after the other.
• When these pulses (energy) reaches the ears the eardrum vibrates.
• And thus we hear the Sound.

Question 2.
Explain how sound is produced by your school bell.
Answer:

• The school bell produces sound through a process known as vibration.
• When the bell is struck, it starts to vibrate, causing the air molecules around it to vibrate as well.
• This creates a pressure wave that travels through the air as a sound wave, eventually reaching our ears and allowing us to hear the sound of the bell.

Question 3.
Why are sound waves called mechanical waves?
Answer:
Sound waves require a material medium to travel that’s why they are called mechanical waves.

Question 4.
Suppose you and your friend are on the moon. Will you be able to hear any sound produced by your friend ?
Answer:
No, we will not be able to hear any sound on moon, as moon doesn’t have any atmosphere.

Question 5.
Which wave property determines (a) loudness, (b) pitch ?
Answer:
The amplitude of the wave determines the loudness.
Loudness α (Amplitude)²

Question 6.
Guess which sound has a higher pitch guitar or car horn ?
Answer:
Pitch describes how the brain interprets the frequency of Sound. So, the guitar has a higher pitch.

Question 7.
What are wave length, frequency, time period and amplitude of a sound wave ?
Answer:
i) Wavelength: The distance between two consecutive crest (or) troughs is called the Wavelength.

It is denoted with Greek letter λ (lambda).

ii) Frequency: The number of oscillations of the density of the medium at a place per unit time is called the frequency of the sound wave. It is denoted with Greek letter v (nu) \(=\frac{1}{\mathrm{~T}}\)

iii) Time Period : The time taken to complete one oscillation of the density of the
medium is called the time period of the sound wave.

iv) Amplitude: The magnitude of the maximum disturbance in the medium on either side of the mean value is called the Amplitude. It is represented by letter (A).

(or) It is the \(\boldsymbol{\leftarrow}\) distance of crest or trough.

Question 8.
How are the wavelength and frequency of a sound wave related to its speed ?
Answer:
Speed of Sound = Frequency × Wavelength
v = λν

Question 9.
Calculate the wavelength of a sound wave whose frequency is 220 Hz and speed is 440 m/s in a given medium.
Answer:
Sound Wave : Frequency ν=220 Hz; Speed v=440 ms^-1
v = λν
Wave Length =

∴ Wavelength of a sound wave λ = 2m

Question 10.
A person is listening to a tone of 500 Hz sitting at a distance of 450 m from the source of the sound. What is the time interval between successive compressions from the source?
Answer:
Tone: Frequencey v=500 Hz
Time interval between successive compression of the source T= \(\frac{1}{v}=\frac{1}{500}\)= 0.002sec

Question 11.
Distinguish between loudness and intensity of sound.
Answer:

Loudness	Intensity
1) Loudness is determined by Amplitude.	1) Intensity of sound depends on energy.
2) It is energy per unit area of wave.	2) It is also energy per unit area of wave.
3) It is dependent on the interpretation of the ear.	3) It is independent on the interpretation of the ear.

Question 12.
In which of the three media, air, water or iron, does sound travel the fastest at a particular temperature ?
Answer:
Sound travels fastest in solids, so sound travels fast in iron than water and air.

Question 13.
An echo is heard in 3 s. What is the distance of the reflecting surface from the source, given that the speed of sound is 342 ms^-1?
Answer:
Speed of sound = 342 ms^-1;
Time taken to hear echo = 3 sec
Distance of the reflecting source

Question 14.
Why are the ceilings of concert hails curved ?
Answer:
The ceilings of the concert halls are curved in order make the sound to reach all cor­ners after reflection, so that it is audible to every person.

Question 15.
What is the audible range of the average human ear ?
Answer:
20 Hz to 20000 Hz (or) 20 Hz to 20 kHz is the audible range.

Question 16.
What is the range of frequencies associated with (a) Infrasound ? (b) Ultrasound?
Answer:
a) Infrasound : Sound wave frequencies between 1 Hz to 20 Hz.
b) Ultrasound : Sound wave of the frequency above 20 kHz.

Examples

Question 1.
A sound wave has a frequency of 2 kHz and wavelength 35 cm. How long will it take to travel 1.5 km?
Answer:
Given, Frequency, o = 2 kHz = 2000 Hz ; Wavelength, X= 35 cm = 0.35 m
We know that speed, v of the wave = wavelength x frequency
The time taken by the wave to travel a distance, d of 1.5

Thus sound will take 2.1 s to travel a distance of 1.5 km.

Question 2.
A person clapped his hands near a cliff and heard the echo after 2s. What is the dis­tance of the cliff from the person if the speed of the sound, v is taken as 346 ms^-1 ?
Answer:
Given, Speed of sound, v = 346 ms^-1
Time taken for hearing the echo, t = 2s
Distance travelled by the sound = v x t = 346 ms^-1 x 2 s = 692 m
In 2 s sound has to travel twice the distance between the cliff and the person.
Hence, the distance between the cliff and the person = 692 m/2 = 346 m.

9th Class Physical Science Chapter 11 Questions and Answers (Lab Activities)

(Page No. 82) Activity -11.1

Question 1.
1. Take a tuning fork and set it vibrating by striking its prong on a rubber pad. Bring it near your ear.
2. Do you hear any sound ?
3. Touch one of the prongs of the vibrating tuning fork with your finger and share your experience with your friends.
4. Now, suspend a table tennis ball or a small plastic ball by a thread from a support [Take a big needle and a thread, put a knot at one end of the thread and then with the help of the needle pass the thread through the ball].Touch the ball gently with the prong of a vibrating tuning fork.
5. Observe what happens and discuss with your friends.

Vibrating tuning fork just touching the suspended table tennis ball
Answer:
When the ball is touched by a vibrating prong the tennis ball also starts vibrating.

(Page No. 82) Activity 11.2

Question 2.
1) Fill water in a beaker or a glass up to the brim. Gently touch the water surface with one of the prongs of the vibrating tuning fork, as shown in figure (a).
2) Next dip the prongs of the vibrating tuning fork in water, as shown in figure (b).
3) Observe what happens in both the cases?
4) Discuss with your friends why this happens.

Answer:
In case -1 vibrating prong brought near the surface of water the water particles on the surface starts vibrating (riples gets produced).
In case – II vibrating prong produces waves in water when it immersed in glass of water.

(Page No. 84) Activity 1.3

Question 3.
Make a list of different types of musical instruments and discuss with your friends which part of the instrument vibrates to produce sound.
Answer:
String Instruments → Veena, Violin, Guitar, Sitar, Ek-tara.
Membrane Instruments → Mridangam, Tabla, Dholak, Dappu. ’
Aerophones → Flute, Harmonica.

(Page No. 86) Activity 11.4

Question 4.
1) Take a slinky. Ask your friend to hold one end. You hold the other end. Now, stretch the slinky as shown in Fig (a). Then give it a sharp push towards your friend.
2) What do you notice ? If you move your hand pushing and pulling the slinky alternatively, what will you observe?
3) If you mark a dot on the slinky, you will observe that the dot on the slinky will move back and forth parallel to the direction of the propagation of the disturbance.

Answer:
1) The region where turns of the coil come closer called Compression (C).
2) The region where turns move further called rarefactions (R).
So, waves produced by a slinky are longitudinal waves.

(Page No. 94) Activity 11.5

Question 5.
1) Take two identical pipes, as shown in below figure. You can make the pipes using chart paper. The length of the pipes should be sufficiently long as shown.
2) Arrange them on a table near a wall.
3) Keep a clock near the open end of one of the pipes and try to hear the sound of the clock through the other pipe.
4) Adjust the position of the pipes so that you can best hear the sound of the clock.
5) Now, measure the angles of incidence and reflection and see the relationship between the angles.
6) Lift the pipe on the right vertically to a small height and observe what happens.
Answer:

Sound follows laws of reflection ∠i=∠r
When we lift the pipe on the right vertically to a small height the sound can’t be head at other end. This is due to ∠i ≠∠r

AP State Board new syllabus AP Board Solutions Class 9 Physics 10th Lesson Work and Energy Questions and Answers.

AP 9th Class Physical Science 10th Lesson Questions and Answers Work and Energy

9th Class Physics 10th Lesson Work and Energy Questions and Answers (Exercise)

Question 1.
Look at the activities listed below. Reason out whether or not work is done in the light of your understanding of the term ‘work’.
a) Suma is swimming in a pond.
b) A donkey is carrying a load on its back.
c) A windmill is lifting water from a well.
d) A green plant is carrying out photosynthesis.
e) An engine is pulling a train.
f) Food grains are getting dried in the sun.
g) A sailboat is moving due to wind energy.
Answer:
Suma is swimming in a pond :
a) Suma pushes water backwards (Force) : She goes in forward direction. Displacement is opposite to force so work done is negative.
b) A donkey is carrying a load on its back : Displacement is perpendicular to force, so work done by the donkey is zero.
c) A wind – mill is lifting water from a well : Displacement is indirection of force, so work done is positive.
d) A green plant is carrying out photosynthesis : No work is done as it is a chemical process.
e) An engine is pulling a train : Force and displacement are in the same direction. So, work done is positive.
f) Food grains are getting dried in the sun : Drying of grains in sun doesn’t involve Force & displacement no work done.
g) A sailboat is moving due to wind energy: Wind displaces sailboat, so work done is positive.

Question 2.
An object thrown at a certain angle to the ground moves in a curved path and falls back to the ground. The initial and the final points of the path of the object lie on the same horizontal line. What is the work done by the force of gravity on the object ?
Answer:

Here the displacement of the object and the gravitational force acting on the object are perpendicular to each other.
So, work done by the force of gravity on the object is zero.

Question 3.
A battery lights a bulb. Describe the energy changes involved In the process.
Answer:
The energy changes involved In the process are as follows:

Question 4.
Certain force acting on a 20 kg mass changes its velocity from 5 ms^-1 to 2 ms^-1. Calculate the work done by the force.
Answer:
Mass m = 20 kg; Initial velocity u = 5 ms^-1

Question 5.
A mass of 10 kg is at a point A on a table. It is moved to a point B. If the line joining A and B is horizontal, what is the work done on the object by the gravitational force? Explain your answer.
Answer:
Here the displacement of the object and the gravitational are perpendicular to each other, so work done is zero.

Question 6.
The potential energy of a freely falling object decreases progressively. Does this violate the law of conservation of energy ? Why ?
Answer:

• No, -it doesn’t violate law conservation energy.
• Some of Potential Energy (P.E) is converted into Kinetic Energy (K.E).
• Some of its energy is used to overcome air resistive force.

Question 7.
What are the various energy transformations that occur when you are riding a bicycle ?
Answer:

Question 8.
Does the transfer of energy take place when you push a huge rock with all your might and fail to move it ? Where is the energy you spend going ?
Answer:
When we push a huge rock.

• the energy is used to overcome the inertia of rock.
• some energy is used to overcome friction.

Question 9.
A certain household has consumed 250 units of energy during a month. How much energy is this in joules ?
Answer:
Energy consumed in a month = 250 units    
= 250 kWh (1 unit = 1 kWh)
= 250 x 3.6 x 10⁶ J = 900 x 10⁶ J
= 9 x 10⁸ J [1 kWh = 3.6 x 10⁶ J]

Question 10.
An object of mass 40 kg is raised to a height of 5m above the ground. What is its potential energy ? If the object is allowed to fall, find its kinetic energy when it is half-way down.
Answer:
Object: Mass m = 40 kg; Height h = 5 m
Acceleration due to gravity g = 10 ms^-2
Gravitational potential energy P. E = mgh
i) E = 40 x 10 x 5 = 2000J
ii) At half way K.E =

K.E = 1000J

Question 11.
What is the work done by the force of gravity on a satellite moviner round the earth? Justify your answer.
Answer:
The force of gravity acting on a satellite moves the satellite in a circular path. Since, the force of gravity acts at right angle to the displacement of the satellite (Figure), so work done,
W = Fs cos 90° = 0.

Question 12.
Can there be displacement of an object in the absence of any force acting on it ? Think. Discuss this question with your friends and teacher.
Answer:

• Yes, displacement is possible without the involvement of force.
• Celestial bodies move in the space without any external force acting on them.

Question 13.
A person holds a bundle of hay over his head for 30 minutes and gets tired. Has he done some work or not ? Justify your answer.
Answer:
Work = Force x Displacement.
No, work is done by the person as the force and displacement are perpendicular to each other.

Question 14.
An electric heater is rated 1500 W. How much energy does it use in 10 hours ?
Answer:
Energy consumed = workdone ; t = 10 hrs ; P = 1500 W = 1.5 kWh
Workdone = Power x time
⇒ W = Pt = 1.5 x 10 = 15 kWh

Question 15.
Illustrate the law of conservation of energy by discussing the energy changes which occur when we draw a pendulum bob to one side and allow it to oscillate. Why does the bob eventually come to rest ? What happens to its energy eventually ? Is it a violation of the law of conservation of energy ?
Answer:
When pendulumiraised from A to C due to change in position it acquires P.E.

• When we release the bob its P.E change to K.E and reaches A
• Due to the K.E it moves to ‘B’ and again acquire P.E.
• This motion gets repeated.
• During the transition some energy is utilised to overcome air resistive & gravitational force.
• Due to this it slows down and stops eventually.
• So, the energy is conserved.

Question 16.
An object of mass, m is moving with a constant velocity, v. How much work should be done on the object in order to bring the object to rest ?
Answer:
Object: Mass = m ; Velocity = v
To bring the object to rest the work done by the force would be equal and opposite.
W = \(-\frac{1}{2}\)mv²

Question 17.
Calculate the work required to be done to stop a car of 1500 kg moving at a velocity of 60 km/h.
Answer:
Car: Mass m = 1500 kg
Initial velocity u = 60 kmh^-1
[ ∵ kmh^-1 to ms^-1, Multiply with \(\frac{5}{18}\)
= 16.66 ms^-1
As it comes to rest.
Final velocity v = 0
To stop the car – ve work must be done by the Force.

Question 18.
In each of the following a force, F is acting on an object of mass, m. The direction of displacement is from west to east shown by the longer arrow. Observe the diagrams carefully and state whether the work done by the force is negative, positive or zero.

Answer:

Work done = 0
Force ⊥ displacement

Work done = Positive
Force and displacement are in the same direction.

Work done = negative
Force and displacement are in opposite direction.

Question 19.
Soni says that the acceleration in an object could be zero even when several forces are acting on it. Do you agree with her ? Why ?
Answer:
Yes, if the several force acting on them constitute a balanced force, then the net force is zero.
Then there will be no acceleration.

Question 20.
Find the energy in joules consumed in 10 hours by four devices of power 500W each.
Answer:
Devices: Power =500 W; No. of devices n = 4; Time of usage t=10 hrs
Total power
[∵ 1 kWh=1000 W]

Question 21.
A freely falling object eventually stops on reaching the ground. What happens to its kinetic energy ?
Answer:
When an object falling freely

• some of its K.E is utilized to overcome air resistive force.
• some of the energy is converted to sound & heat energy.
• the rest is absorbed by the earth.

9th Class PS 10th Lesson Questions and Answers (InText)

Question 1.
A force of 7N acts on an object. The displacement is say 8m, in the direction of the force (figure). Let us take it that the force acts on the object through the displacement. What is the work done in this case?
Answer:
Force F = 7N ; Displacement s = 8m
Work done = Force x displacement ⇒ W=Fxs = 7×8 = 56J

Question 2.
When do we say that work is done ?
Answer:
When a force acts on an object and the object moves, we say that the force has done the work on the object.

Question 3.
Write an expression for the work done when a force is acting on an object in the direction of its displacement.
Answer:
Work done = Force x displacement ⇒ W = Fs

Question 4.
Define 1 J of work.
Answer:
When a force of 1 Newton acts on an object causing a displacement of 1 metre.

Question 5.
A pair of bullocks exerts a force of 140 N on a plough. The held being ploughed is 15 m long. How much work is done in ploughing the length of the field ?
Answer:
Bullocks (Pair): Force exerted by them F = 140 N
Distance ploughed by them s = 15m
W = Fs = 140 x 15 = 2100 J
2100J is the work done by pair of bullocks for ploughing a distance of 15m.

Question 6.
What is the kinetic energy of an object ?
Answer:
Kinetic Energy : The energy of an object by virtue of its motion is called Kinetic Energy.

Question 7.
Write an expression for the kinetic energy of an object.
Answer:
Expression for kinetic energy :

Let us consider a block of mass ‘m’.

• As it is at Rest.
• It’s Initial velocity u = 0.
• Let a force ‘F’ acting on the block.
• Moved with a velocity V from A to B, travelled a distance AB.
• According to Newton’s 2nd law,

Question 8.
The kinetic energy of an object of mass, m moving with a velocity of 5 ms^-1 is 25 J. What will be its kinetic energy when its velocity is doubled ? What will be its kinetic energy when its velocity is increased three times ?
Answer:

Question 9.
What is power?
Answer:
Rate of doing work (or) rate of transfer on energy is called Power.

Question 10.
Define 1 watt of power.
Answer:
If work is done at the rate of 1 Joule per second, then the power delivered is 1 watt.
1 watt = \(\frac{1 \text { joule }}{\text { second }} ; P=\frac{W}{t}\)

Question 11.
A lamp consumes 1000J of electrical energy in 10 s. What is its power?
Answer:
Electrical energy consumed by lamp =1000J
Time t = 10 sec
Power P = \(\frac{W}{t}\)=\(\frac{1000}{10}\) = 100 W

Question 12.
Define average power.
Answer:
Total energy consumed by the total time taken is considered as average power.
\(P_{\text {Avg }}=\frac{\text { Total energy }}{\text { Total time }}\)

Examples

Question 1.
A force of 5 N is acting on an object. The object is displaced through 2 m in the direction of the force (Figure). If the force acts on the object all throughout the displacement. Find the work done by the force.
Answer:
Given data, Force (F) = 5N ; Displacement (s) = 2m
Workdone (W) = Force (F) x Displacement (s)
W = F x s = 5N x 2m = 10 J = W = 10 J
Hence, the work done by the force is 10 J.

Question 2.
A porter lifts a luggage of 15 kg from the ground and puts it on his head 1.5 m above the ground. Calculate the work done by him on the luggage.
Answer:
Mass of luggage, m = 15 kg and displacement, s = 1.5 m
Work done, W = F x s = mg x s
= 15 kg x 10 ms^-2 x 1.5 m = 225 kg ms^-2 m = 225 N m = 225 J
Work done is 225 J.

Question 3.
An object of mass 15 kg is moving with a uniform velocity of 4 ms^-1. What is the kinetic energy possessed by the object ?
Answer:
Mass of the object, m = 15 kg, velocity of the object, v = 4 ms^-1
From Eq. E_k = \(\frac{1}{2}\) mv²
= \(\frac{1}{2}\) x 15 kg x 4 ms^-1 x 4 ms^-1 = 120 J
The kinetic energy of the object is 120 J.

Question 4.
What is the work to be done to increase the velocity of a car from 30 km h^-1 to 60 km h^-1 if the mass of the car is 1500 kg ?
Answer:
Mass of the car, m = 1500 kg
initial velocity of car, u=30 km h^-1 = \(\frac{30 \times 1000 \mathrm{~m}}{60 \times 60 \mathrm{~s}}\) =25/3 ms^-1
Similarly, the final velocity of the car, v =60 kmh^-1 = 50/3ms^-1
Therefore, the initial kinetic energy of the car,
E_kd = \(\frac{1}{2}\) mu² = \(\frac{1}{2}\) × 1500 kg × (25/3 ms^-1)²
=156250/3 J
The final kinetic energy of the car, E_f = \(\frac{1}{2}\) × 1500 kg×(50 / 3ms^-1)²
= 625000 / 3 J.
Thus, the work done = Change in kinetic energy
= E_Kf -E_Ki = 156250 J

Question 5.
Find the energy possessed by an object of mass 10 kg when it is at a height of 6 m above the ground. Given, g =9.8 ms^-2
Answer:
Mass of the object, m =10kg,
Displacement (height), h=6m and acceleration due to gravity, g = 9.8ms^-2
From Eq. Potential energy = mgh
Potential energy = mgh=10 kg × 9.8 ms^-2 × 6m =588J.
The potential energy is 588 J.

Question 6.
An object of mass 12 kg is at a certain height above the ground. If the potential energy of the object is 480 J, find the height at which the object is with respect to the ground. Given, g=10 ms^-2.
Answer:
Mass of the object, m=12 kg, potential energy, E_p=480J
E_p=mgh
480 J = 12 kg× 10 ms^-2 × h ⇒ h = \(\mathrm{h}=\frac{480 \mathrm{~J}}{120 \mathrm{~kg} \mathrm{~ms}^{-2}}\) = 4m
The object is at the height of 4m

Question 7.
Two girls, each of weight 400 N climb up a rope through a height of 8 m. We name one of the girls A and the other B. Girl A takes 20 s while B takes 50 s to accomplish this task. What is the power expended by each girl?
Answer:
i) Power expended by girl A:
Weight of the girl, mg = 400N; Displacement (height), h=8 m; Time taken, t=20s
From Eq. power

ii) Power expended by girl B :
Weight of the girl, mg=400N; Displacement (height), h=8m; Time taken, t=50s

Power expended by girl A is 160 W
Power expended by girl B is 64 W

Question 8.
A boy of mass 50 kg runs up a staircase of 45 steps in 9s. If the height of each step is 15 cm, find his power. Take g =10 ms^-2
Answer:
Weight of the boy, mg=50 kg × 10 m s^-2 =500 N
Height of the staircase, h =45 × 15 / 100 m =6.75 m;
Time taken to climb, t = 9s
From Eq. Power,

Power is 375 W

9th Class Physical Science Chapter 10 Questions and Answers (Lab Activities)

(Page No. 54) Activity 10.1

Question  1.
Kamali is preparing for examinations. She spends lot of time in studies. She reads books, draws diagrams, organises her thoughts etc.,
You are working hard to push a huge rock. Let us say the rock does not move despite all the effort.
You climb up the steps of a staircase and reach the second floor of a building just to see the landscape from there.
We have discussed in the above paragraphs a number of activities which we normally consider to be work in day-to-day life. For each of these activities, ask the following questions and answer them :

i) What is the work being done on ?
Answer: Force.

ii) What is happening to the object ?
Answer: Object is undergoing some change.

iii) Who (what) is doing the work?
Answer: Force

(Page No. 56) Activity 10.2

Question 2.

• Think of some situations from your daily life involving work.
• List them.
• Discuss with your friends whether work is being done in each situation.
• Try to reason out your response.
• If work is done, which is the force acting on the object?
• What is the object on which the work is done ?
• What happens to the object on which work is done ?

Answer:

(Page No. 56) Activity 10.3

Question 3.

• Think of situations when the object is not displaced in spite of a force acting on it.
• Also think of situations when an object gets displaced in the absence of a force acting on it.
• List all the situations that you can think of for each.
• Discuss with your friends whether work is done in these situations.

Answer:
1) Situations where an object is not displaced inspite of a force acting on it :

• when a book is placed on a table.
• a heavy box placed on a rough surface may not move because the force of friction is greater than the applied force.

2) Situations, where an object gets displaced in the absence of a force acting on it :

• Some objects, such as a rolling ball or a falling apple, may move without the application of an external force. This is due to the object’s inherent properties, such as its shape or weight, that cause it to move.
• A ball rolling on a smooth surface will continue to roll for a short distance even after the external force that set it in motion is removed.

(Page No. 58) Activity 10.4

Question 4.
– Lift an object up. Work is done by the force exerted by you on the object. The object moves upwards. The force you exerted is in the direction of displacement. However, there is the force of gravity acting on the object.
1) Which one of these forces is doing positive work ?
2) Which one is doing negative work ?
– Give reasons.
Answer:
1) Muscular Force has done the positive work.
2) Gravitational Force has done negative work.

(Page No. 60) Activity 10.5

Question 5.

• A few sources of energy are listed above. There are many other sources of energy. List them.
• Discuss in small groups how certain sources of energy are due to the Sun.
• Are there sources of energy which are not due to the Sun?

Answer:
1) There are many other sources of energy besides those listed, including: Geothermal energy – energy harnessed from heat within the earth’s crust. Hydroelectric power – energy generated from the movement of water. Nuclear power – energy generated through nuclear reactions. Biomass energy – energy from organic matter such as wood, crops and waste. Wind power – energy generated from the wind’s movement.

2) Most of the sources of energy on Earth are ultimately derived from the Sun. For example, solar energy is directly harnessed from the Sun’s radiation, while biomass energy is the result of photosynthesis, which converts solar energy into chemical energy stored in organic matter. Wind power is also indirectly linked to the Sun, as differences in atmospheric pressure caused by uneven heating from the Sun create wind.

3) However, there are some sources of energy that are not directly linked to the Sun. For example, geothermal energy, tidal power etc.

(Page No. 62) Activity 10.6

Question 6.
Take a heavy ball. Drop it on a thick bed of sand. A wet bed of sand would be better. Drop the ball on the sand bed from height of about 25 cm. The ball creates a depression.

• Repeat this activity from heights of 50 cm, 1m and 1.5 m.
• Ensure that all the depressions are distinctly visible.
• Mark the depressions to indicate the height from which the ball was dropped.
• Compare their depths.
• Which one of them is deepest ?
• Which one is shallowest? Why ?
• What has caused the ball to make a deeper dent ?
• Discuss and analyse.

Answer:
1) Ball dropped from 1.5 m height create deepest depression on sand.
2) Ball dropped from 25 cm is the shallowest, it is dropped from a very small height.
3) Height [greater the height, greater the depression].

(Page No. 62) Activity 10.7

Question 7.

• Set up the apparatus as shown in the adjacent figure.

• Place a wooden block of known mass in front of the trolley at a convenient fixed distance.
• Place a known mass on the pan so that the trolley starts moving.
• The trolley moves forward and hits the wooden block.
• Fix a stop on the table in such a manner that the trolley stops after hitting the block. The block gets displaced.
• Note down the displacement of the block. This means work is done on the block by the trolley as the block has gained energy.

– From where does this energy come?
Answer: The trolley got energy due to its motion.

– Repeat this activity by increasing the mass on the pan. In which case is the displacement more?
Answer: We can observe that when mass increases the displacement also increases.

– In which case is the work done more?
Answer: Work – done will be more when we increase the mass on the pan.
– In this activity, the moving trolley does work and hence it possesses energy.

(Page No. 66) Activity 10.8

Question 8.
1) Take a rubber band.
2) Hold it at one end and pull from the other. The band stretches.
3) Release the band at one of the ends.
4) What happens?
Answer: The band comes to its original shape.

5) The band will tend to regain its original length. Obviously the band had acquired energy in its stretched position.
6) How did it acquire energy when stretched ?
Answer: Rubber band got energy due to change in its shape.

(Page No. 66) Activity 10.9

Question 9.
1) Take a slinky as shown in the adjacent figure.

2) Ask a friend to hold one of its ends.
You hold the other end and move away from your friend. Now you release the slinky.

3) What happened?
Answer: The slinky comes back and retains its original shape. Due to change in its shape.

4) How did the slinky acquire energy when stretched ?
Answer: When we stretch the slinky we apply a force on it which does work on the slinky.

5) Would the slinky acquire energy when it is compressed ?
Answer: Yes, it acquires energy when it is compressed.

(Page No. 66) Activity 10.10

Question 10.
1) Take a toy car. Wind it using its key.
2) Place the car on the ground.

3) Did it move?
Answer: Yes. It moves.

4) From where did it acquire energy?
Answer:  It acquires energy from our body while winding the key.

5) Does the energy acquired depend on the number of windings ?
Answer: Yes, the energy acquired depend on the number of windings.

6) How can you test this?
Answer: When we wind the key lesser no.of turns it goes small distance.
If we wind the key greater (full) it goes greater distance.
This is due greater change in shape of the windings.

(Page No. 66) Activity 10.11

Question 11.
1) Lift an object through a certain height. The object can now do work. It begins to fall when released.
2) This implies that it has acquired some energy. If raised to a greater height it can do more work and hence possesses more energy.
3) From where did it get the energy? Think and discuss.
Answer:  It got energy due to change in its position (height).

(Page No. 66) Activity 10.12

Question 12.

• Take a bamboo stick and make a bow as shown in the adjacent figure.
• Place an arrow made of a light stick on it with one end supported by the stretched string.
• Now stretch the string and release the arrow.
• Notice the arrow flying off the bow.
• Notice the change in the shape of the bow.
• The potential energy stored in the bow due to the change of shape is thus used in the form of kinetic energy in throwing off the arrow.

Self – Interpretation

(Page No. 66) Activity 10.12

Question 12.

• Take a bamboo stick and make a bow as shown in the adjacent figure.
• Place an arrow made of a light stick on it with one end supported by the stretched string.
• Now stretch the string and release the arrow.
• Notice the arrow flying off the bow.
• Notice the change in the shape of the bow.
• The potential energy stored in the bow due to the change of shape is thus used in the form of kinetic energy in throwing off the arrow.

Self – Interpretation

(Page No. 70) Activity 10.14

Question 14.
1) Many of the human activities and the gadgets we use involve conversion of energy from one form to another.
2) Make a list of such activities and gadgets.
3) Identify in each activity/gadget the kind of energy conversion that takes place.
Answer:
1) Cell phone – Chemical energy – Electrical energy.
2) Mixer / Grinder – Electrical energy – Mechanical energy.
3) Speakers – Electrical energy – sound energy

(Page No. 72) Activity 10.15

Question 15.
An object of mass 20 kg is dropped from a height of 4m. Fill in the blanks in the following table by computing the potential energy and kinetic energy in each case.  For simplifying the calculations, take the value of g as 10 ms^-2

Height at which object is located m	Potential energy (EP = mgh) J	Kinetic energy (Ek = mv/2) J	EP + EK J
4
3
2
1
Just above the ground

Answer:

Height at which object is located	Potential energy (EP = mgh) J	Kinetic energy (Ek = mv/2) J	EP + EK J
4	800	0	800 + 0 = 800
3	600	200	600 + 200 = 800
2	400	400	400 + 400 = 800
1	200	600	200 + 600 = 800
ground	0	800	0 + 800 = 800

(Page No. 72) Activity 10.16

Question 16.
1) Consider two children, say A and B. Let us say they weigh the same. Both start climbing up a rope separately. Both reach a height of 8 m. Let us say A takes 15s while B takes 20s to accomplish the task.

2) What is the work done by each?
Answer: Work done by both of them is same.

3) The work done is the same. However, A has taken less time than B to do the work.
4) Who has done more work in a given time, say in 1s?
Answer: Work done By A & B is W = mg but A has taken less time, so ‘A’ does more work.

(Page No. 74) Activity 10.17

Question 17.
1) Take a close look at the electric meter installed in your house. Observe its features closely.
2) Take the readings of the meter each day at 6.30 am and 6.30 p.m.
3) Do this activity for about a week.
4) How many ‘units’ are consumed during the day time?
5) Tabulate your observations.

Last Meter Reading	First Meter Reading	No.of units Consumed per day

6) Now, multiply no. of units per day × 30.
7) You can get total units consumed for a month.
8) Compare this with electricity bill you received.
Self Interpretation.

These AP 9th Class Biology Important Questions 12th Lesson Improvement in Food Resources will help students prepare well for the exams.

AP 9th Class Biology 12th Lesson Improvement in Food Resources Important Questions

Class 9 Biology Chapter 12 Important Questions – 2 Marks

Question 1.
Name the three stages in which farming practices are divided.
Answer:
a) choice of seeds
b) nurturing of crop plants
c) protection of the growing and harvested crops.

Question 2.
What are genetically modified crops ?
Answer:
The crops obtained by introducing a gene that provides the desired characters is known Genetically modified crops.

Question 3.
Define hybridisation.
Answer:
Hybridisation refers to crossing between genetically dissimilar plants, to obtain, better variety of crops.

Question 4.
“Shorter the duration of the crop from sowing to harvesting, the more economical is the variety” – Give reason for this.
Answer:
Due to short duration of crop growth, farmers can grow more crops in a year, and reduce the cost of crop production.

Question 5.
What are macro – nutrients.?
Answer:
The nutrients required by plants in larger quantity is called macro – nutrients. They are – Nitrogen, phosphorus, potassium, calcium, magnesium & sulphur.

Question 6.
Name the nutrients that plant obtain from air and water ?
Answer:
Air – Carbon dioxide and Oxygen
Water – Hydrogen and Oxygen

Question 7.
What are the major group of activities involved for improving of crop yields ?
Answer:
a) Crop variety improvement
b) Crop production improvement
c) Crop protection management.

Question 8.
What are the different ways / methods of hybridisation ?
Answer:
Hybridisation can be
a) inter varietal – between different variety of crops.
b) interspecific – between two species of same genus.
c) intergenic – between two different genera.

Question 9.
What are the main characters that are required in a crop during its improvement ?
Answer:
a) Disease resistance
b) Response to fertiliser
c) Product quality
d) High yield

Question 10.
How do deficiency of nutrients affect the crop ?
Answer:
Deficiency of any nutrient affects physiological processes in plants including repro-duction, growth and succeptibility to diseases.

Improvement in Food Resources Class 9 Important Questions – 3 Marks

Question 1.
State the difference between Macro – Nutrients and Micro Nutrients.
Answer:

Macro – Nutrients	Micro – Nutrients
1) These are required by crops in larger quantity.	1) These are requried by crops in very small quantity.
2) Six macro nutrients are Nitrogen, Phosphorous, potassium, .calcium, magnesium & sulphur	2) Seven micronutrients are Iron, manganese, boron, zinc, copper, molybdenum and chlorine.

Question 2.
Differentiate between Manure and fertilizer.
Answer:

Manure	Fertilizer
1) It consists of organic matter	1) It consists of inorganic matter.
2) Prepared from animal excreta and plant waste	2) It is prepared commercially from chemicals.
3) Its use causes no pollution.	3) It caused pollution in soil and water.

Question 3.
What is organic farming ?
Answer:
It is the farming in which no chemical fertilisers, pesticides or herbicides are used. But uses all organic matter for its growth like manure, neem leaves as pesticides and for grain storage.

Question 4.
State the preventive and control measures used before grains are stored.
Answer:
a) Cleaning of the grains.
b) Proper drying of the produce in sunlight, there should be no moisture.
c) Fumigation of produce using chemicals that kills pests.

Question 5.
Name some varieties of bees used for commercial honey production.
Answer:
a) Apis cerana indica – Indian bee
b) A dorsats – rock bee (local varieties)
c) A florae – the little bee
d) A mellifera – Indian bee variety

Question 6.
How does insect posts attack the plant and affect it.
Answer:

1. They cut the root, stem and leaf.
2. They suck the cell sap from various parts of the plant.
3. They bore into stem and fruits.
   This way they affect the health of the crop and reduces yield.

Question 7.
Give different methods of weed control ?
Answer:
Weeds can be controlled by different methods :
a) Weedicides:
These are the chemicals sprayed on the weeds to kill them. Excessive use is poisonous and causes environmental pollution.

b) Mechanical removal:
In this method weeds are uprooted by removing manually or by machines.

c) Preventive methods:
Proper seed bed preparation, timely sowing of crops, inter cropping and crop rotation helps in weed control.

Question 8.
What are the new variety traits obtained by cross breading of Indian and exotic breeds of poultry ?
Answer:
The new variety / traits obtained by cross breeding of Indian and exotic breeds of poultry are :

1. The number and quality of chicks.
2. Dwarf broiler parent for commercial chick production.
3. Summer adaptation capacity / tolerance to high temperature.
4. Low maintenance requirements.
5. Reduction in the size of the egg laying bird with ability to utilise more fibrous and cheaper diet, formulated using agricultural by products.

Question 9.
State the difference between egg layer and broiler.
Answer:

Egg layers	Broiler
1) They are fed on protein rich food.	1) They are fed on vitamin rich supple­mentary feed for good growth rate.
2) Used for laying eggs.	2) Used for meat purposes. Lot of protein included in the diet.

Question 10.
Give one word for the following.
a) Farming without the use of chemicals as fertilisers, herbicides and pesticides is known as ________
b) Rowing of wheat and ground nut on the same field is called as __________
c) Planting soya bean and maize in alternate rows in the same field is called as ___________
d) Growing different crops on a piece of lands in pre – planned succession is known as __________
e) Causative organism of any disease is called __________
Answer:
a) Organic farming
b) Mixed cropping
c) Inter cropping
d) Crop rotation
e) Weeds
f) Pathogen.

Question 11.
Cultivation practices and crop yield are related to environmental condition. Explain.
Answer:
Cultivation practices and crops yield are related to environmental condition various crops require different climatic conditions, temperature and photoperiod, for their growth and completion of life cycle. On the basis of seasonal variations, crops in India can be classified into three main groups :
a) Rabi crop : It is a winter season crop grown from November to April.
b) Karif crop : It is a rainy season crop grown from June to October.
c) Zaid crop : It is a summer season crop grown from April to June.

Question 12.
Arrange these statements in correct sequence of preparation of green manure.
a) Green plants are decomposed in soil. r
b) Green plants are cultivated for preapring manure or crop plant parts are used
c) Plants are ploughed and mixed into the soil.
d) After decomposition it becomes green manure.
Answer:
i) b ii) c iii) a iv) d

Question 13.
In agricultural practices, higher input gives higher yield.
Answer:
1) In agricultural practices, higher inputs give higher yield.

2) Higher inputs in the form of sowing of seeds of improved variety, application of better manures and fertilisers, proper spraying of pesticides and weedicides, improved threshing and harvesting crops leads to increase in crop productivity. This also means the higher money inputs to raise the yield.

Financial condition of farmers allow them to take up different farming practices and technologies. The farmer’s purchasing capacity for input decides cropping system and production practices.

Question 14.

i) Which type of cropping system is in this picture ?
ii) What is the use of this type of inter cropping system ?
iii) With this type of cropping system, both crops will get beenfit or not ?
Answer:
i) The name of the cropping system is inter cropping.
ii) This inter – cropping ensures maximum utilisation of the nutrients supplied, and also prevents pests and diseases from spreading to all the plants belonging to one crop in a field.
iii) Yes, in inter cropping method both crops will get benefit and give better returns.

Question 15.

i) Name the type of breed in the picture.
ii) Which breeds show resistance to diseases?
iii) Which breeds select for long lactation periods?
Answer:
i) The type of breeds are indigenous milch breed of cattle.
ii) Local breeds such as Red Sindhi, Sahiwal show resistance to diseases.
iii) Exotic or foreign breeds such as Jersey Brown swill are selected for long location periods.

Important Questions on Improvement in Food Resources Class 9 – 5 Marks

Question 1.
Differentiate between the following.
i) Bee keeping and poultry farming.
ii) Capture fishery & cultrue fishery.
Answer:

i) Bee keeping	Poultry farming
1) Practice of rearing honey bees for the commercial production of honey and bee wax is called apiculture or bee keeping.	1) Practice of raising domestic flows for commercial production of egg and meat is called poultry farming.
2) Varieties of honey bees used for production of honey are Apis cerena indica, A. dorsata and A. Florae	2) The common poultry birds are chicken, turkeys, ducks, geese guinea – fowls and pigeons.

ii) Capture fishery	Culture fishery
1) Method of obtaining fish from natural resources, is called capture fishery.	1) Method of obtaining fish from fish farms is called culture fishery.
2) It is carried out both in inland and marine water resources.	2) It is carried out mostly in inland water resources and near sea shore.

Question 2.
What do you understand by composite fish culture ?
Answer:

1. Practice of culturing combination of five or six spices of fish in a single fish pond is termed as composite fish culture.
2. Selection of several species of fish for culturing in a pond helps to enhance yield with same cost and to utilise most of available food in the water reservoirs.
   Fishes are selected on the basis of following characteristics.

a) The selected species are fast growing. For example, when common Indian carps (rohu, catla and mrigal) an exotic carps (sivler carp, grass carp) are selected for culturing, they give 8 -9 times more yield.

b) The fishes selected should not compete with each other for space and nutrition. They should live in-district zones inside the pond.
For example, calta and silver carp live mostly in surface zone, rohu and grass carp live in middle zone and mrigal and common carp live at the bottom.

c) The feeding habits of species selected should be district.
For example, silver carp feeds on phytoplanktons, catla feeds on Zoo planktons, rohu and mrigal feed on decaykig plant and detritus, grass carp feeds on aquatic plants and weeds. Thus, they can be grown together.
Composing fish farming is advantageous, economical and profitable from business point of view.

Question 3.
Name two types of animal feed and write their functions.
Answer:
The food required by dairy animals is called feed. The dairy animals must get adequate palatable, laxative appetising and balances ration with sufficient greens and all nutrients in appropriate amounts. Large quantity of water is also required for milk production.

Two types of normal feed for dairy animals are :
i) Roughages
ii) Concentrates

i) Roughages : This part of cattle feed contains mostly fibres which come from bay (straw of cereals or Bhusa, green folders (cow pea, berseem etc) and silage.

ii) Concentrates : These are mixtures of substances containing less fibres and relatively excessive amount of protein, fat, carbohydrates, vitamins, minerals etc. A balanced ration containing all nutrients in proper amounts plus sufficient water must be offered to dairy animals at frequent intervals. Besides this, various additives whicji contain micronutrients, antibiotics etc, must also be given to cattle to promote. their milk production.

Question 4.
Why are improved poultry breeds developed ?
Answer:

1. poultry farming is undertaken to raise domestic fowl for egg production and chicken meat.
2. For this improved poultry breeds are developed and farmed to produce layers for eggs and broilers for meat.
3. The cross breeding programmes between Indian and foreign breeds for variety improvement are focused on developing new varieties for the following desirable traits.
   • The number and quality of chicks.
   • The dwarf broiler parent for commercial chick production
   • Tolerance to high temperature $ Low maintenance requirements
   • Reduction in the size of the egg – laying bird possessing the ability to utilise more fibrous and economical diet that are formulated using agricultural by products.

Question 5.
Enlist the criteria for the selection of crops for mixed cropping.
Answer:
Mixed cropping is employed to minimise risk and as an insurance against crop failure due to abnormal wealther conditions. The main criteria’s for selection of the crops for mixed cropping are as follows :
a) Duration of Crops :
One of the crops should be a long duration and other should be a short duration crop.

b) Growth habit:
One of the crops should be growing tall and the other should be growing short. The component crops should have different canopy.

c) Nutrient Demand :
One of the component crops should require lesser nutrients than the other crop.

d) Root pattern :
One of the crop should be deep – rooted while the other should be shallow – rooted.

e) Water requirement:
One of the component crops should require lesser water than the other.

Question 6.
What are the various methods of irrigation in India ?
Answer:
Most of agriculture in India is rainfed, several different kinds of irrigation system are adopted to supply water to agricultural lands. The resources are wells, canals, rivers and tanks.
a) Wells : Dug wells and tube wells. In dug wells water is collected from water bearing strata.

b) Tubewells : Can tap water from deeper strata.

c) Canals : Most extensive irrigation system. Canals receive water from reservoirs or rivers, The main canal is divided into branch canals having further distributaries to irrigate fields.

d) River lift system : Water is directly drawn from the river for supplementing irrigation in arease close to rivers.

e) Tanks : These are small storage reservoirs, which intercept and store the run-off of smaller catchment areas.

Question 7.
Large amount of food grains get spoiled every year in India due to improper stor¬age of food grains. How can this be avoided ?
Answer:
Food grains get spoiled by insects, fungi, rodents, bacteria, moisture, temperature in the place of storage.
Storage losses can be minimised by following preventive and control measures :

1. The seeds / grains that are to be stored should be dry, with no moisture in it.
2. The grains should be cleaned.
3. The grains should be fumigated using chemicals that kills pest.
4. The storage houses should be water proof.
5. The grains should be stored in sealed gunny bags or metal containers.
6. The bags should be stacked in order in pile for proper fumigation, and should be kept few centimetres away from the wall.
7. The walls and floors should be water proof with no holes in it, to avoid rodents, pests.

Question 8.
Explain different types of fisheries.
Answer:
The different types of fisheries are marine fisheries, inland fisheries, capture fishing, mari culture and aqua culture.
Marine fisheries
Marine fishes are caught using fishing nets. Large schools of fishes is located by satellites. Some are farmed in sea water.

Mari culture
Marine fishes are cultured in sea water, this type of culturing known as mariculture.

Inland fisheries:
The fisheries done in fresh water resources like canals, ponds, reservoirs and rivers is called inland fisheries.

Capture fishing:
It is done in sea water, estuaries and lagoons.

Aqua culture :
Culture of fish done in different water bodies is called aqua culture.

Question 9.
What are the factors for which variety improvement of crop is done ?
Answer:
a) Biotic and Abiotic resistance :
Crop should be resistant to biotic factors like disease, insects, pests and abiotic factor
like droughty, salinity, heat, cold, frost & water logging.

b) Change in maturity duration :
Short duration maturity allows farmer to grow more crops in a year and reduces the cost of crop production.

c) Wider adaptability:
Crop should be able to adapt to change environmental conditions.

d) Higher yield : It increases production of crops.

e) Desirable eagranomic :
The tallness and dwarfness of crop. Dwarfness is required for cereals, so that less nutrients are consumed.

Question 10.
What are fertilisers ? Excess use of fertilisers is not advisable. Explain.
Answer:

1. Fertilisers are obtained artificially on commercial basis.
2. It is a chemical which contains the nutrients required for the crop to grow.
3. ertilisers supply various nutrients as they are nutrient specific, eg – urea provides nitrogen.
4. Mixed fertiliser provides any two mixture of nutrients. They are expensive but their use yield large production. Hence a factor of high cost farming.
   Excessive, use of fertilisers are not advisable as
   a) It leads to soil and water pollution
   b) It can destroy the fertility of soil. As the soil is not replemished, microorganisms in the soil are harmed by fertilizers.

Question 11.
What are the different patterns of cropping ?
Answer:
Different ways of cropping system of growing crops are : a) Mixed cropping b) Inter cropping c) Crop rotation

a) Mixed Cropping:
It is a method in which two or more crops grow simultaneously on the same piece of land. Ex : Wheat + grain
This helps in reduction of risk factor.

b) Inter – Cropping :

1. It is a method of growing two or more crops simultaneously on the same field in a definite patterns.
2. A few row of one crop alternate with a few rows of second crop. Ex : Soya beans, Maize.

c) Crop – Rotation :
The growing of different crops on a piece of land in a pre – planned succession is known as crop – rotation.
The availability of moisture and irrigation facility decides the choice of crop to be cultivated afthr one harvest.

Extra Questions on Improvement in Food Resources Class 9 – 4 Marks

Question 1.
Nutrients supplied by air, water and soil

Source	Nutrients
Air Water Soil	carbon, oxygen hydrogen, oxygen i) Macronutrients : nitrogen, phosphorus, potassium, clacium, magnesium, sulphur ii) Micronutrients : iron, manganese, boron, zinc, copper, molybdenum, chlorine

i) Name the Nutrients which supplied by air.
ii) What are macro nutrients ?
iii) What are micro nutrients ?
iv) What happens if these lack ?
Answer:
i) Carbon and oxygen will be supplied by air.
ii) Macro nutrients are the nutrients which are required in large quantity to the plants.
iii) Micro nutrients are the nutrients which are required in less quantity to the plants.
iv) The deficiency of these nutrients affects the physiological processes in plants including, reproduction, growth and susceptibility to diseases.

Question 2.
Read the paragraph and answer the following questions ?

Fish is a cheap source of animal protein for our food. Fish production includes the finned true fish as well as shellfish such as prawns and molluscs. There are two ways of obtaining fish. One is from natural resources, which is called capture fishing. The other way is by fish farming, which is called culture fishery.

i) What is the cheap source of animal protein for our food ?
ii) How many ways of obtaining fish are there ?
iii) Define culture fishery ?
iv) What is the basic source of fish ?
Answer:
i) Fish is the cheap source of animal protein for our food.
ii) There are two ways of obtaining fish.
iii) The fish farming is known as cultrue fishery.
iv) The water source can be either sea water or fresh water, such as in rivers and ponds.

These AP 9th Class Biology Important Questions 5th Lesson The Fundamental Unit of Life will help students prepare well for the exams.

AP 9th Class Biology 5th Lesson The Fundamental Unit of Life Important Questions

Class 9 Biology Chapter 5 Important Questions – 2 Marks

Question 1.
What is cell theory ?
Answer:
The cell theory explains that …….
a) All the plants and animals are composed of cells and that the cell is the basic unit of life.
b) All cells arise from pre existing cells.

Question 2.
What are multicellular organisms ?
Answer:
The organisms which are formed with more than one cell are called multicellular organisms.
Ex : Plants and animals.

Question 3.
On which aspect the shape and size of cells are related to ?
Answer:
The shape and size of the cells are related to the specific function of the cell that perform.

Question 4.
What is division of labour in multicellular organisms ?
Answer:
Different parts of the human body perform different functions. That is division of labour.

Question 5.
What is plasma membrane ?
Answer:
The plasma membrane is the outermost covering of the cell that separates the contents of the cell from its external environment.

Question 6.
Plasma membrane is also called as selective permeable membrane.
Answer:

1. The plasma membrane allows or permits the entry and exit of some materials in and and out of the cell.
2. It also prevents movement of some other materials.
   So the plasma membrane is also called as selective permeable membrane.

Question 7.
What is diffusion ?
Answer:
The spontaneous movement of a substance from a region of high concentration to a region where its concentration is low. It is called diffusion.

Question 8.
What is osmosis ?
Answer:
The movement of water molecules through such a selectively permeable membrane is called osmosis.

Question 9.
What is hypotonic solution ?
Answer:
If the medium surrounding the cell has a higher water concentration than the cell, meaning that the outside solution is very dilute, the cell gain water by osmosis. Such as solution is called hypotonic solution.

Question 10.
What is Isotonic solution ?
Answer:
If the medium has exactly the same water concentration as the cell, there will be no net movement of water across the cell membrane such a solution is known as Isotonic solution.

Question 11.
What is a hypertonic solution ?
Answer:
If the medium has a lower concentration of water than the cell, meaning that it is a very concentrated solution, the cell will be water by osmosis. Such a solution is known as a hypertonic solution.

Question 12.
Define endocytosis. Give an example.
Answer:
The flexibility of the cell membrane enables the cell to engulf in food and other material from its external environment. Such processes are known as endocytosis.

Question 13.
What is cell wall ?
Answer:
The rigid outer cover present in plant cell in addition to the plasma membrane is called cell wall.

Question 14.
Define the plasmolysis.
Answer:
When a living plant cell loses water through osmosis there is shrinkage or contraction of the contents of the cell and from the cell wall.’This phenomenon is known as plasmolysis.

Question 15.
What is Nucleus ?
Answer:
A dark coloured, spherical or oval dot like structure near the centre of each cell is called Nucleus.

Question 16.
Name some cell organelles.
Answer:
Endoplasmic reticulum, Golgi Apparatus, lysosomes, mitochondria and plastids, Nucleus, plasma membrane, cell wall, cytoplasm.

Question 17.
What is biogenesis ?
Answer:
The process of some of the proteins and lipids help in building the cell membrane is called biogenesis.

Question 18.
Define the following.
i) Mitosis
ii) Meiosis
Answer:
i) Mitosis : The process of cell division by which most of the cells are divide for growth is called mitosis.
ii) Meiosis : The process of cell division by which reproductive cell to form gametes is called Meiosis.

Question 19.

i) Identify the diagram
ii) Label the parts a, b
iii) Which letter indicates the Nucleus.
Answer:
The diagram is cells of an onion peel
i) Part a – Cell
ii) Part b – Indicates the Nucleus

Question 20.

i) Identify the figure.
ii) Is it round. If not how is it ?
Answer:
i) It is a nerve cell.
ii) It is not round, It is long and branched.

Question 21.

i) Name the diagram.
ii) Why is it prokaryotic cell ?
Answer:
i) The diagram is prokaryotic cell.
ii) There is no nuclear member over the nucleus so it is prokaryotic cell.

Question 22.

Name the figure.
Answer:
Mitochondria

Question 23.
What happens if there is no cell ?
Answer:

1. As the cell is the basic structure of the life, so one cannot survive without a cell.
2. If there is no cell, there is no life.

Question 24.
Do you say that all cells are alike in shape, size; otherwise mention some shapes of cells.
Answer:

1. No, All cells are not alike in shape, size.
2. Some cells are round, circular, long and branched, spindle shaped.

Question 25.
Bindu said that every cell arise from pre – existing cells. Do you agree with this statement ? Support your answer.
Answer:
Yes. Bindu’s statement is correct only. I agree with that as per the cell theory proposed Schleidan & Schwanan Virchow “All cells arise from pre – existing cells”.

Question 26.
Bacteria do not have chloroplast but some bacteria are photo autotrophic in nature and perform photosynthesis. Which part of bacterial cell performs this ?
Answer:
In most photosynthetic bacteria, pigments and enzymes involved in photosynthesis are found in infoldings of plasma membrane that extend into the cytoplasm.

Question 27.
Why is the Golgi Apparatus called the secretary organelles of the cell ?
Answer:
This is because it packages material synthesized in the ER and dispatches it to intracellular and extra cellular targets.

The Fundamental Unit of Life Class 9 Important Questions – 3 Marks

Question 1.
How can you say the cell is the fundamental unit of cell ? Or a building unit of cell?
Answer:
Yes, cell is a building unit of an organism. The body of an organism is made up of various organ systems like digestive system, reproductive system etc., The organ systems are made up of various organs which in turn are made up of tissues. A tissue is a group of cells performing the same function. Hence a cell is the basic building unit or fundamental unit of an organism.
It can be represented as ……….
Cell → Tissue → Organ → Organ system – organism

Question 2.
Why does the skin of your finger shrink when you wash clothes for a long time ?
Answer:

1. Soap solution is a hypertonic solution.
2. It is more concentrated than the cells of our skin.
3. As we know when a cell is immersed in a hypertonic solution, water leaves the cell by the processes exosmosis resulting in shrinkage of the cell.
4. ln the same way, while washing clothes for a long time, exosmosis occurs in the skin celfs resulting in the shrinkage of skin cells of our fingers.

Question 3.
How are chromatin, chromatid and chromosomes related to each other ?
Answer:

1. Chromatin occurs as diffuse network of fine filaments in non – dividing Nucleus.
2. At the time of cell division, chromatin material becomes condensed into rod – like structures called chromosomes.
3. Each chromosome has a centromere and two arms called chromatid.

Question 4.
Why do plant cells possess large sized vacuole ?
Answer:

1. In mature plant cells, a large central vacuole occupying most of the cell space is present.
2. It is because in the plant cells, vacuole does not only store food material and waste products, rather it also contains cell sap.
3. The cell sap helps to keep the cell turgid and provides rigidity and support to it.
4. Vacuole also helps in maintaining water balance of the cell.
5. Thus plant cell possess large sized vacuole.

Question 5.
Which kind of plastid more common in ……………….
a) Roots of the plant
b) Leaves of the plant
c) Flowers and fruits
Answer:
a) Leucoplasts are more common in non – photosynthetic organs such as roots of the plant.
b) Chloroplasts are more common in green photosynthetic organs such as leaves of the plant.
c) Chromoplasts are more common in colourful parts such as flowers and fruits.

Question 6.
Which cell organelle controls most of the activities of the cell ?
Answer:

1. Nucleus controls the most of the activities of the cell such as cellular metabolism, reproduction etc due to the presence of DNA which contains all the information- required the cell.
2. DNA directs the synthesis of RNA, which in turn directs the synthesis of proteins and enzymes required for various cellular activities.

Question 7.
Why are lysosomes are called suicidal bags of the cells ?
Answer:

1. Lysosomes are called suicidal bags of the cells because they are a kind of waste disposal system of cell.
2. This is due to the presence of powerful digestive enzymes which are capable of break down all organic material.
3. Lysosomes help to keep the cell clean by digesting any foreign material such as bacteria, food particles etc, as well as worn – out cell organelles.

Question 8.
How is a bacterial cells different from an onion peel cell ?
Answer:

1. A bacterial cell is a prokaryotic cell which contains a poorly defined region called nucleoid.
2. All the membrane bound cell organelles are absent in a bacterial cell.
3. An onion peel cell is a Eukaryotic plant cell which contains a well defined nucleus and all the membrane – bound cell organelles such as mitochondria, ER etc.,

Question 9.
Write the name of different plant parts in which chromoplast, chloroplast and Leucopast are present ?
Answer:

1. Chromoplasts are present in flowers, fruits and other colourful parts of the plant.
2. Chloroplasts are present in green coloured parts eg. Leaves of the plant.
3. Leucoplasts are present in non – photosynthetic and storage organs of the plant.
   Ex : Seeds, fruits, tubers, roots etc.

Question 10.
If you are provided with some vegetables to cook. You generally add salt into the vegetables during cooking process after adding salt, vegetables release water. What mechanism is responsible for this ?
Answer:

• The mechanism responsible for this process is exosmosis.
• Addition of salt during cooking makes the surrounding medium hypertonic i.e., the surrounding medium has lower water concentration than the cells of vegetables.
• As we know when a cell is immersed in a hypertonic solution water leaves the cell by the process of exosmosis resulting in its shrinkage. Therefore vegetables release water afer adding salt during cooking process.

Question 11.
A person takes concentrated solution of salt, after some time, he starts vomiting. What is the phenomenon responsible for such situation ? Explain.
Answer:

• The phenomenon responsible for such situation is exosmosis.
• Concentrated solution of salt is hypertonic to the cells of our body i.e., concentration of water molecules in it is lesser than the concentration of water molecules in the cells of our body. ,
• When a person drinks concentrated salt solution, water comes out of the cells of the alimentary canal by the process of exosmosis causing a loss of water in the cells.
  This results in dehydration, diarrhea and vomiting.

Question 12.
Differentiate between diffusion and osmosis.
Answer:

Diffusion	Osmosis
1) It occurs in any medium.	1) It occurs in liquid medium only.
2) Diffusing molecules may be solid, liquid or gaseous solutes.	2) It involves movement of solvent molecules only.
3) Semi permeable membrane is not required.	3) Semi permeable membrane is required.

Question 13.
Differentiate between Rough endoplasmic reticulum and smooth endoplasmic reticulum.
Answer:

Rough endoplasmic reticulum	Smooth endoplasmic reticulum
1) They have ribosomes attached on their surfaces.	1) They do not have ribosomes attached on their surfaces.
2) RER manufactures proteins and transports them to various places.	2) SER helps in manufacturing lipids and transports them to various places.

Question 14.
Write the differences between a plasma membrane and a cell wall ?
Answer:

Plasma membrane	Cell wall
1) It holds cellular contents and controls passage of materials in and out of cell.	1) It gives protection, strength and rigidity to the cell.
2) It is semipermeable in nature and allows entry of selected molecules into the cell.	2) It is completely permeable in nature.
3) It is not elastic.	3) It is elastic and controls the cells turgidity preventing its bursting.

Question 15.

i) Identify the diagram given in the picture.
ii) Mention the function of mitochondria.
iii) Why is it called power house of the cell ?
Answer:
i) The given diagram is Mitochondria.
ii) Mitochondria is responsible for cellular response.
iii) Mitochondria stores the energy and it releases whenever the cell requires energy.
So it is called power house of the cell.

Question 16.

i) Label the parts of a, b, c.
ii) What are the functions of Rough Endoplasmic Reticulum ?
iii) What are the functions of smooth Endoplasmic Reticulum ?
iv) What is the function of Ribosomes ?
Answer:
i) Part a = Rough Endoplasmic Reticulum
Part b = Ribosomes
Part c = Smooth Endoplasmic Reticulum

ii) Functions of Rough Endoplasmic Reticulum
a) They helps in synthesise of proteins.

iii) Functions of smooth Endoplasmic Reticulum.
a) They helps in the manufacture of molecules, or lipids important for cell function.

iv) Functions of Ribosomes : a) Ribosome helps in synthesize of proteins.

Question 17.

i) Name the part a.
ii) Who described it first ?
iii)What is the function of Golgi complex ?
Answer:
i) Name of the part a = Golgi Apparatus
ii) Cabrillo Golgi discovered it first.
iii) Function of Golgi complex.
a) The Golgi apparatus fucntions include the storage, modification and packaging of products in vesicles.
b) It also involved in the formation of lysosomes.

Important Questions on The Fundamental Unit of Life Class 9 – 5 Marks

Question 1.
In brief state what happens when ….
a) dry raisins are left for some time in pure water and later transferred to sugar solution ?
b) a red blood cell is kept in concentrated saline solution ?
c) the plasma membrane of a cell breaks down ?
d) Rheo leaves are boiled in water first and then a drop of sugar syrup is put on it ?
e) Golgi apparatus is removed from the cell ?
Answer:
a) The apricots swell due to osmosis initially and when transferred to sugar solution shring again due to exosmosis.

b) RBCs shrink due to exosmosis.

c) It would help lead to scattering of cell organelles and there will be no functioning of the organs.

d) There will be no change in cell shape or size because the cells are dead due to boiling.

e) Function of Golgi apparatus is packing, storing and transfer of protein. It would affect the functioning of cell.

Question 2.
If cells of onion peel and RBQ are separately kept in hypotonic solution, what will happen to each of them ? Explain the reason for your answer.
Answer:
a) Both the cells will swell up.

b) RBC will burst easily while cells of onion peel will resist the bursting to some extent. Because
i) When kept in a hypotonic solution, the onion cells will become turgid because the water will enter the cell due to osmosis. But the cell wall present outside the cell provide it’s rigidity and does not let any harm to occur.
ii) Where as in RBC the movement of water inside the cell due to osmosis will lead to bursting of the cell because it does not have a rigid cell wall.
Therefore RBC will burst easily while onion cell peels will resist it to some extent.

Question 3.
How does Amoeba obtains its food ?
Answer:

1. Amoeba obtains its food by the process of endocytosis.
2. Endocytosis refers to the invagination of a small region of the plasma membrane to engulf the food particle and ultimately forming an intrecellular membrane-bound vesicle.
3. Depending upon the type of food material, endocytosis may be i) Phagocytosis ii) Pinocytosis
4. Phagocytosis is a common method of feeding in some protozoans, eg. Amoeba. In this method, a part of plasma membrane invaginates in the region of solid food particles and engulf it.
5. The membrane enclosed vesicle called phagosome containing the food particle detaches from the plasma membrane into the cytoplasm, where it’s contents are digested by lysosomal engymes.

Question 4.
What are the consequences of the following conditions ?
a) A cell containing high water concentration than the surroudings medium.
b) A cell having low water concentration than the surrounding medium.
c) A cell having equal water concentration to its surrounding medium.
Answer:
a) A cell having high water concentration than the surrounding medium will lose water due to exosmosis. The cell will ultimately shrink.

b) A cell having low water concentration than the surrounding medium will gain water due to endosmosis and the cell will ultimately swell up.

c) A cell having equal water concentration to its surrounding medium will remain in its original state as there is no net movement of water into or out of the cell.

Question 5.
Illustrate only a plant cell as seen under electron microscope. How is it different from animal cell ?
Answer:

Differences between a plant cell and animal cells :

Plant cell	Animal cell
1) Cell wall is present.	1) Cell wall is absent.
2) A large central vacuole is present.	2) Many small vacuoles are present.
3) Nucleus is peripheral in position	3) Nudes is centrally placed.
4) Golgi aparatus is present in the form of freely distributed units called dictyosomes.	4) Single Golgi apparatus is present generally near the nuclear envelope.
5) Centrioles are absent.	5) Centrioles are present.
6) Plastids are present.	6) Plastids are absent.
7) Mitochondria are comparatively fewer in number.	7) Mitochondria are numerous.
8) Lysosomes are rarely present.	8) Typical lysosomes are present.
9) Reserve food material is mainly starch.	9) Reserve food material is mainly glycogen.

Question 6.
Draw a neat labelled diagram of an animal cell.
Answer:

Question 7.
Draw a well labelled diagram of an Eukaryotic nucleus. How Is it different from nucleoid?
Answer:

Differences between a plant cell and animal cells :

Nucleus	Nucleoid
1) It is in larger size.	1) It is smaller in size.
2) It is bounded by double membrane.	2) It is not bounded by any membrane.
3) It contains Nucleolus.	3) It does not contain Nucleolus
4) It contains DNA associated with histone proteins.	4) It contains naked DNA ie., DNA is not associated with histone proteins.
5) It is present in eukaryotic cells.	5) It is present in prokaryotic cells.
6) Plastids are present	6) Plastids are absent.

Question 8.
i) What is cell division ? Write about types of cell divisions.
ii) Write the differences between mitosis & meiosis through a diagram.
Answer:
i) Cell division : The process by which new cells are made is called cell division.

ii) Types of cell divisions : There are two types of cell division : a) Mitosis b) Meiosis
a) Mitosis : Mitosis is the process by which a cell replicates its chromosomes and then segregates them, producing two identical nuclei in preparation for cell division.
b) Meiosis : Meiosis is a type of cell division in sexually reproducing organisms that reduces the number of chromosomes in gametes.

iii) Differences between mitosis or meiosis are :

Mitosis	Meiosis
1) This takes place in somatic cells.	1) This takes place in reproductive cells.
2) Completed in one stage.	2) Completed in two stages.
3) It produces two daughter cells.	3) It produces four daughter cells.
4) The daughter cells have the same number of choromosomes as mother cell.	4) The daughter cells have half the number of chromosomes than that of the mother cells.

Question 9.
Write the differences between Cytoplasm and Nucleoplasm.
Answer:
Differences between Cytoplasm anjd Nucleoplasm.

Cytoplasm	Nucleoplasm
i) Cytoplasm is the protoplasm which lies outside the nucleus.	i) It is the part of protoplasm that lies inside the nucleus.
ii) It is semi-fluid jelly like substance.	if) It is transparent.
iii) It contains various inorganic subst­ances forming clear true solution as well as organic substances lipids, proteins and carbohydrates.	iii) It contains chromatin material.
iv) It contains various organelles and inclusions.	iv) ft is a colloidal substance having similar composition to cytoplasm but contains more of nucleotides.

Extra Questions on The Fundamental Unit of Life Class 9 – 4 Marks

Question 1.
Read the paragraph and answer the following questions :

Plant cells, in addition to the plasma membrane, have another rigid outer covering called the cell wall. The cell wall lies outside the plasma membrane. The plant cell wall is mainly composed of cellulose, cellulose is a complex substance and provides structural strength to plants. When a living plant cell loses water through osmosis there is shrinkage or contraction of the contents of the cell away from the cell wall. This phenomenon is known as plasmolysis.

a) Name the outer cover which the cell have in addition to plasma membrane.
Answer:
Cell wall is the rigid outer cover in addition to the plasma membrane.

b) What is cell wall made up of ?
Answer:
Cell wall is made up of cellulose.

c) What is the function of cell wall ?
Answer:
It provides structural strength to plants.

d) Is there cell wall present in the animal cell ?
Answer:
No, the cell wall is not present in the animal cell.

e) What is plasmolysis ?
Answer:
When a living plant cell loses water through osmosis there is shrinkage or contraction of the contents of the cell away from the cell wall. This phenomenon is called plasmolysis.

Question 2.
Read the paragraph and answer the following questions :

Plastids are present only in plant cells. There are two types of plastids – chromoplasts (coloured plastids) and leucoplasts (white or colourless plastids). Chromo plasts containing the pigment chlorophyll are known as chloroplasts. Chloroplasts are important for photosynthesis in plants. Chloroplasts also contain various yellow or orange pigments in addition to chlorophyll. Leucoplasts are primarily organelles in which materials such as starch, oils and protein granules are stored.

a) Name the type of plastids in which photosynthesis process takes place.
Answer:
Chioroplasts are the plastids in which photosynthesis process takes place.

b) Fruits and flowers have colour due to the presence of plastids.
Answer:
Chromoplasts.

c) What is the similarity between mitochondria and plastids ?
Answer:
Like the mitochondria, plastids also have their own DNA and Ribosomes.

d) What is the function of leucoplasts ?
Answer:
Leucoplasts store the materials such as starch, oils, and protein granules.