AP State Syllabus SSC 10th Class Biology Important Questions 4th Lesson Excretion
10th Class Biology 4th Lesson Excretion 1 Mark Important Questions and Answers
What is meant by excretion?
Excretion is a biological process involved in separation and removal of wastes from body.
When you are on a field trip, your friend collected a sticky substance oozed out by a plant called gum. What are the plants you observe which give gum ?
Acacia, Neem, Drumstick, Eukalyptus and Sapota are the gum yielding plants present in our surroundings.
What are primary metabolites?
The substances that are directly involved in normal growth and development and reproduction of a plant are called primary metabolites, e.g.: Carbohydrates, fats and proteins.
What are secondary metabolites?
The inorganic substances that are not directly involved in the normal growth, development and reproduction of an organism are called secondary metabolites, e.g.: Alkaloids, tannins, resins, gums and latex, etc.
Write any two substances present both in blood and urine.
Glucose, Sodium, Potassium, Chlorides, Urea, Creatinine, Uric Acid, Calcium, Phosphorous.
When you are on a field trip, you might have collected some plants which contain alkaloids. Name the alkaloids which are harmful to us.
Nicotine, Morphine, Cocaine.
Write the names of any two excretory organs in human beings.
Kidney, Skin, Lungs, Liver, Large Intestine.
Which plants in your surroundings are useful for the production of medicines?
Neem, Datura, Tulasi, Calotropis.
The body of a person is filled with extra water and waste products. His hands and feet were swollen. What do we call this condition? Failure of which system causes this condition?
This condition is called Uremia. This condition is caused due to failure of excretory system (Kidneys).
How do plants get rid of their waste materials?
- Plants can get rid of excess water by transpiration and guttation.
- The other nitrogenous waste products are stored in leaves, bark and fruits when these dead leaves, bark and ripe fruits fall off from the tree then the waste products in them are removed.
Give an example of a case where organ donation can save one’s life.
- Kidney of a brain dead person can be donated to save the life of renal failure persons.
- Cornea of a dead person can be donated to the blind.
- Bone marrow can be donated to save life of persons suffering from blood related genetic disorders.
Why is urine yellow in color?
Because of urochrome, urine is yellow in colour. It forms in the liver from dead RBC.
Write two slogans to popularize the awareness on “Organ Donation”.
- Organ donation saves lives.
- Donate organs today for better tomorrow.
- Donate organs – Live after death.
Write two healthy habits which you practice to protect your kidneys from diseases.
- Drink plenty of water.
- Eat low salt diet that saves kidney life.
- Drink more fruit juices.
What precautions you have to take in the observation of internal structure of mammalian kidney?
- Wash the kidney thorougly with water.
- Ensure that blood is completely drained from it.
- Wash your hands with antibacterial lotion after completing the dissection.
Write two secondary metabolites, which you use in your daily life.
Gum, Rubber, Coffee are the examples for secondary metabolites which we use in our daily life.
Why is vasopressin not secreted when a person drinks a lot of water?
Vasopressin is secreted only when concentrated urine is to be passed out. When a person drinks a lot of water, there will be no need to secrete concentrated urine. The excess water taken by the person will be sent out in the form of dilute urine. Hence, vasopressin is not secreted.
In urine excretory system much water is reabsorbed. What happens if it doesn’t occur?
If water is not reabsorbed it leads to excessive repeated dilute urination called diabetes insipidus. If water does not reabsorbed we would dry up in few hours.
A substance given below consists of other three substances. What is that substance? Where is it produced? Uric Acid, Sodium, Oxalate, Urine.
Urine contains all the other three substances. It is produced in kidney.
Name the hospitals where the organ transplantation facility is available in Hyderabad.
Organ transplantation facility is available only in two government hospitals. They are NIMS (Nizam Institute of Medical Sciences) and Osmania hospital. This facility is also available in some corporate hospitals.
What is anabolism?
The synthesis of complex molecules in living organisms from simpler ones together with the storage of energy.
What is catabolism?
The breakdown of complex molecules in living organisms to form simpler ones, together with the release of energy.
What is the meaning of the word excretion in Latin?
In Latin ex means out, crenere means shift.
What are the wastes produced during metabolic activities?
Carbon dioxide, water, nitrogenous compounds like ammonia, urea, uric acid, bile pigments, excess salts, etc., are the wastes produced during metabolic activities.
What is the most poisonous of all waste products?
Ammonia is the most poisonous of all waste products.
What are the substances present in blood?
Substances present in blood are glucose, sodium, potassium chloride, urea, creatinine, uric acid, cholesterol, triglycerides, calcium, phosphorous, bilirubin, proteins, etc.
What are the substances present in urine?
The substances present in urine are protein, creatinine, calcium, phosphorous, uric acid, etc.
What are the substances present in both blood and urine in common?
The substances present in the blood and urine in common are sodium, potassium, glucose, chlorides, urea, proteins, creatinine, calcium, phosphorous and uric acid.
What are the substances that need to be removed from body?
Creatinine, uric acid, urea, cholesterol and calcium.
In human beings excretory system consists of?
The excretory system in human beings consists of a pair of kidneys, a pair of ureters, urinary bladder and urethra.
Where are the kidneys present in human body?
In human body kidneys are present in the abdominal cavity attached to dorsal body wall one on either side of backbone.
What is the shape and colour of the kidney?
The kidney is bean shaped and reddish brown in colour.
What is the size of the kidney?
The size of the kidney is 10 cm in length, 5 – 6 cm in breadth and 4 cm in thickness.
Why is the position of right kidney lower than the left kidney?
The position of right kidney is lower than left kidney due to the presence of liver above it.
Which artery brings oxygenated blood to kidney?
Renal artery brings oxygenated blood to kidney.
What are the two distinct regions present inside the kidney?
The two distinct regions present inside the kidney are
- dark coloured outer zone called the cortex and
- pale coloured inner zone called medulla.
Each kidney is made up of how many nephrons?
Each kidney is made up of about 1.3 to 1.8 million nephrons.
What is the other name of Nephron?
The other name of nephron is uriniferous tubule.
What are the two basic parts of nephron?
The two basic parts of nephron are malphigian body and renal tubule.
What is meant by Glomerulus?
Malphigian body consists of a blind cupshaped broader end of nephron called Bowman’s capsule and bunch of blood capillaries called Glomerulus.
Which blood vessel forms glomerulus in Bowman’s capsule?
Afferent arteriole forms glomerulus in Bowman’s capsule.
Renal tubule consists of how many parts?
Renal tubule consists three parts. They are Proximal convoluted tubule (PCT), Loop of Henle, and Distal Convoluted Tubule (DCT).
What is the major function of proximal convoluted tubule?
Proximal convoluted tubule reabsorbs useful substances like glucose, amino acids, phosphate, potassium, urea and other organic solutes from the filtrate.
What are podocyte cells?
Glomerulus is lined by a single layer of squamous epithelial cells called podocyte cells.
What is the function of loop of Henle?
- In the descending loop of Henle reabsorption of water from the filtrate takes place.
- Ascending loop of Henle is impermeable to water and only ions diffuse out into the surrounding cells.
What is the function of Distal convoluted tubule?
Distal convoluted tubule maintains proper concentration and pH of the urine.
How many stages are involved in formation of urine? What are they?
Formation of urine involves four stages. They are
- Glomerular filtration,
- Tubular reabsorption,
- Tubular secretion and
- Concentration of urine.
The amount of water reabsorption in the tubule depends on?
The amount of water reabsorption in the tubule depends on amount of excess water present in the body and the amount of dissolved wastes to be excreted.
In which region seventy five percent of water content of the nephric filtrate is reabsorbed?
Seventy five percent of water content of the nephric filtrate is reabsorbed in the region of proximal convoluted tubule.
Which hormone is responsible to pass concentrated urine?
Vasopressin is responsible to pass concentrated urine.
What is micturition?
Micturition is the process of discharge of urine from the urinary bladder.
What are the composition of various substances in urine?
The composition of various substances in urine are 96% of water, 2.5% of organic substances and 1.5% of inorganic solutes.
How much amount of urine is excreted per day?
Total amount of urine excreted per day is about 1.6 -1.8 litres.
What is the storage capacity of urinary bladder?
The storage capacity of urinary bladder is 300 – 800 ml.
What is uremia?
If kidneys stop working completely, our body is filled with extra water and waste products. This condition is called uremia.
What is haemodialysis?
Artificial filtering of blood to remove wastes by using dialysis machine is known as haemodialysis.
What is the time required for each dialysis session?
The time required for each dialysis session is 3 to 6 hours.
What are the organs that can be transplanted from brain dead patients?
The organs that can be transplanted from brain dead patients are kidney, liver, heart, lungs, pancreas, skin, bone, intestines and eyes (cornea).
Where is the transplanted kidney fixed in the body of kidney failure patient?
The transplanted kidney is fixed in the body of patient inside the lower abdomen.
What is cadaver transplantation?
The process of transplantation of organs from brain dead patients to another is called cadaver transplantation.
What are the other excretory organs present in human body in addition to kidney?
The other excretory organs present in human body in addition to kidney are lungs, skin, liver, large intestine, salivary glands and lacrimal glands.
What are the waste products excreted by lungs?
The waste products excreted by lungs are carbon dioxide and water.
Sebum of sebaceous glands in skin contains wastes like?
Sebum of sebaceous glands in skin contains wastes like waxes, sterols, hydro carbons and fatty acids.
What are the metabolic wastes of haemoglobin of red blood cells in liver?
The metabolic wastes of haemoglobin of red blood cells in liver are bile pigments like bilirubin, biliverdin and urochrome.
How is urea produced in liver?
Urea is produced in liver by the deamination of proteins.
What are the wastes excreted by intestine?
The wastes excreted by intestine are excess salts of calcium, magnesium and iron.
How do unicellular organisms remove waste products?
Unicellular organisms remove waste products by diffusion from the body surface to the surrounding water.
What is the osmoregulatory organelle in amoeba and paramoecium?
The osmoregulatory organelle in amoeba and paramoecium is contractile vacuole.
In which animal phyla water bathes almost all their cells in body of organisms?
In porifera and coelenterates water bathes almost all their cells in body of organisms.
Through which processes plants get rid of excess water?
Through transpiration and guttation plants get rid of excess water.
What are Raphides?
Waste gets stored in the fruits in the form of solid bodies called Raphides.
What are alkaloids?
The poisonous nitrogenous by products produced by plants are alkaloids.
Which alkaloid is used as antimalarial drug?
Quinine is the alkaloid used as antimalarial drug.
Which flowers and fruits are used to extract sedative scopalamine?
The sedative scopalamine is extracted from the flowers and fruits of Datura stramonium.
What are the alkaloids produced by plants?
The alkaloids produced by plants are nimbin, nicotine, morphine, codeine quinine, reserpine, caffeine/scopolamine, etc.
What are tannins?
Tannins are alkaloids which are carbon compounds.
Which group of plants secretes resin?
Resin secretes by a group of plants Gymnosperms.
What is latex?
Latex is a sticky, milky white substance secreted by plants.
Which plant of latex is used to prepare rubber?
Rubber is prepared from the latex of Hevea braziliensis.
Bio-diesel is obtained from the seeds of?
Bio-diesel is obtained from the seeds of Jatropa.
Which person’s kidney is used for a successful kidney transplantation?
From a close relative kidney can be used for successful transplantation.
What may be the feeling of the patients who are waiting for suitable organ donations due to failure of vital organs?
The patients who are waiting may think that any donor with a kind heart can give them life by donating their organs.
What may be the feeling of a doctor while transplanting the organs?
Doctor is also a human being, he predicts that the transplantation becomes a success.
How can you appreciate the father of Yaswanth Kumar for donating the organs of his brain dead son? (From annexure)
We can appreciate the father of Yaswanth Kumar for his humanity where no one can accept to take or think such a delicate decision of donating the organs of his brain dead son.
What might be the feeling of the father H.V. Shiva Kumar father of Yaswanth Kumar for donating the organs of his son? (From annexure)
The father might have thought that his son can live even after his death in some other people who are in need for the suitable organs. We can appreciate father’s humanity.
What does the society need about organ donation?
The society needs much awareness in organ donation so that we can jsave many lives who are in need of different organs from donors for their survival.
Which substances are present above the normal limits both in the blood and urine in the sample given?
Substances present above the normal limits in the blood are: creatinine, uric acid and cholesterol. Substances present above the normal limits in the urine are creatinine, calcium, uric acid and urea.
When is more urine excreted?
A large intake of liquids or water rich food increases the volume of water in the blood, hence more urine is excreted.
What are the uses of Tannins?
Tannins are used in tanning of leather and in medicines.
What are the economic importance of gums?
Gums are valuable being used as adhesives and binding agents in the preparation of the medicines, food, etc.
Why do we get peculiar smell when you shift the potted plant?
Plants release some peculiar chemical substances into their surroundings into soil through roots. These substances attract useful microorganisms to the plant. Hence we get peculiar smell when we shift the potted plant.
What is chewing gum ? How is it made of?
Chewing gum is a type of gum for chewing made dates back 5000 years. Modern chewing gum originally made of chicle, natural latex from plant.
How do pollen grains affect our health?
Whenever pollen grains enter in our body they cause allergy due to the presence of nitrogenous substances. These allergens cause skin allergy and asthma. Ex: Parthenium.
What are the defensive mechanism developed by plants of your village to protect themselves from the herbivores ? Give two examples.
Plants produce nitrogenous compounds to protect themselves from the herbivores. These compounds are called as alkaloids. For example,
Datura – It produces alkaloid known as scopolamine.
Cactus – Develop spines on the body.
10th Class Biology 4th Lesson Excretion 2 Marks Important Questions and Answers
Fill in the table on the basis of your obervations in field trip.
|S.No||Name of the plant||Secondary metabolites||Uses|
|S.No||Name of the plant||Secondary metabolites||Uses|
Two kidneys are present in human beings as excretory organs. Haritha, whose age is 23 years, donated one kidney to her father. Now she has one kidney only. She gave birth to a female child.
a) How many kidneys are there in Haritha’s daughter?
Harita’s daughter has 2 kidneys,
b) Support your answer.
Bodily changes are not inherited, so Harita’s daughter has 2 kidneys.
What questions do you ask a nephrologist to know more about kidney related diseases?
- How are stones formed in the kidney?
- What is dialysis?
- What is the effect of smoking and alcoholism on kidneys?
- What is ESRD?
Read the following lines and answer the questions.
Liver: It produces bile pigments (bilirubin, biliverdin and urochrome) which are metabolic wastes of haemoglobin of dead R.B.Cs. Urochrome, which is responsible for the amber colour of the urine, is eliminated through urine. Biliverdin and bilirubin are stored in gall bladder and later excreted through bile along with cholesterol and derivatives of steroid hormones, extra drug, vitamins and alkaline salts. Liver is also involved in urea formation.
i) Which substance adds colour to urine?
ii) The site of synthesis of urea in the body is …………..
Look at the picture and answer the questions, (label bottle on left as X and bottle on right as Y)
The above is a procedure of haemodialysis in a hospital.
i) What are the liquids X and Y, in the picture?
ii) What is the purpose of this procedure and for whom is it needed?
i) X – Dialyzing fluid; Y – Urine
ii) It is a process of removal of poisonous nitrogenous wastes from blood. This process is needed by uremic or kidney failure patients.
Prepare four questions to find the reasons for obstructions in excretory system.
- What do we call the complete and irreversible kidney failure?
- What happen if kidney stops working completely?
- What is uremia?
- Is there any solution to this problem?
Name the secondary metabolites which are useful in leather and rubber industry. From which plants we obtain them?
- Latex used in rubber and Tannins used in Leather Industry.
- Latex – Hevea brasiliensis (Rubber Plant) Tannins – Cassia, Acacia.
Prepare four questions you will ask a nephrologist about Kidney failure.
- When does kidney fail?
- What are the symptoms of kidney failure?
- What precautions can we take to prevent failure of kidney?
- Which alternative method can we adopt if kidney fails?
Observe the following table.
|Name of the phylum / organism||Excretory system / organ|
|Porifera||Water bathes all their cells|
|Reptiles, Aves and Mammals||Kidney|
On the basis of above table, write answers to the following questions.
i) In above table, which living organisms contains kidneys as excretory organs like human beings?
Reptiles and Aves.
ii) Write the excretory organs present in Earthworm and Cockroach.
Earthworm – Nephridia Cockroach – Green glands
Observe the following table and answer the questions given below.
|Alkaloid||Name of the plant||Uses|
|Quinine||Cinchona||Anti malarial drug|
i) Which alkaloid we get from the fruit, is used as pain killer?
ii) From which part of the plant do we get Quinine?
Bark of Cinchona
What is called structural and functional unit of kidney? Why?
- Each kidney is made up of more than one million microscopic and thin tubular units called nephrons or uriniferous tubules. Hence nephron is known as structural and functional unit of kidney.
- Nephron’s chief function is to regulate the concentration of water and soluble substances, reabsorbing what is needed and excreting the rest as urine. Hence it is known as functional unit of kidney.
Blood is filtered in Bowman’s capsule of nephron. For the filtration of blood some pressure is needed. How does the pressure arises in Bowman’s capsule?
- Blood flows inside the glomerulus of Bowman’s capsule under the influence of pressure due to the large diameter of afferent arteriole.
- This increases or rise the blood pressure in the glomerulus capillaries leading to ultrafiltration of the blood in the Bowman’s capsule.
Classify the substances given below.
Ptyaline, Leptin, Morphine, Riboflavin, Testosterone, Thyamin, Niacine, Sucrase, Nicotine, Amylase, Retinol, Quinine, Calciferol, Adrenaline, Tripsin.
The above substances can be classified into Enzymes, Hormones, Alkaloids and Vitamins.
Enzymes: Ptyaline, Sucrase, Amylase, Tripsin
Hormones: Testosterone, Adrenaline, Leptin
Alkaloids: Morphine, Nicotine, Quinine
Vitamins: Riboflavin, Thyamin, Niacine, Retinol, Calciferol
How does excretion take place in phylum protozoa?
- Specific excretory organs are absent in unicellular organisms. These organisms remove waste products by simple diffusion from the body surface into the surrounding water.
- Excess water is sent out through contractile vacuoles in fresh water protozoans. Ex: Amoeba surface.
- The major portion of excess water is eliminated by diffusion through body surface.
What are the functions of excretory system?
- Excretory system in animals performs more than one function.
- The primary function of excretory system is to maintain ionic and osmotic balance in the animal body.
- Excretory system helps to maintain appropriate concentration of salts and correct amount of water in the body.
- It also helps in maintaining the body volume.
- The secondary function of excretory system is excretion of nitrogenous wastes and foreign substances such as drugs.
Mention the groups of animals where excretion fakes place through diffusion from body surface.
- In protozoans wastes are excreted by diffusion through body surface.
- Contractile vacuoles present in some protozoans are mainly concerned with the maintenance of osmotic and ionic balance. Excretion is mainly by diffusion.
- In sponges, coelenterates like Hydra, excretion takes place by diffusion.
People in cold countries get very less / no sweat. What changes occur in their skin and in other excretory organs?
- Usually human skin has a unique system keep in equilibrium state with the surrounding temperature.
- During winter season the temperature is low and the body temperature should be heated to balance the tolerance.
- So the water content in our body is sent out in the form of urine.
- Hence, people in cold countries get less sweat or no sweat.
10th Class Biology 4th Lesson Excretion 4 Marks Important Questions and Answers
Analyse the following information and answer the questions.
|Alkaloid||Part of the plant||Uses|
|Reserpine||Roots||Medicine for snake bite|
|Caffeine||Seeds||Central nervous system stimulant|
|Nimbin||Seeds, Barks, Leaves||Antiseptic|
i) Name the alkaloid which is used to cure malaria.
ii) Name the alkaloids used as insecticides.
iii) Which system is stimulated by the alkaloid caffeine?
Central nervous system
iv) Which parts of which plant is used as medicine for snake bite?
The roots of Rauwolfia Serpentina (Snake root)
Which diagram do you draw to label these parts?
- Bowman’s capsule
- Uriniferous tubule.
- Collecting tubule.
Draw the diagram and label the parts.
Fill the following table related to Secondary Metabolites in plants.
|S.No.||Metabolite||Name of the plant||Use|
|S.No.||Metabolite||Name of the plant||Use|
|1.||Resin||Pinus||Used in varnishes|
|2.||Gums||Neem, Acacia||Used as adhesives and binding agents|
|3.||Latex||Hevea braziliensis (Rubber plant)||Rubber preparation|
|4.||Nimbin||Azadirachta indica (Neem)||Antiseptic|
The given parts belong to which system? Draw a neat labelled diagram of the system.
a) Kidneys b) Ureters c) Urinary bladder
The given parts belong to human excretory system.
Read the following passage and answer the questions.
Plants can get rid of excess water by a process like transpiration and guttation. Waste products may be stored in leaves, bark, and fruits. When these dead leaves, bark, and ripe fruits fall off from the tree then waste products in them are removed. Waste gets stored in the fruits in the form of solid bodies called ‘raphides’. However several compounds are synthesized by the plants for their own use especially for defence. Many plants synthesize chemicals and store them in roots, leaves, seeds, etc. for protection against herbivores. Most of the chemicals are unpleasant to taste. Hence herbivores usually do not prefer to eat such plants. Some of the chemicals are toxic and may even kill the animals that eat them.
i) What are raphides?
ii) How do plants protect themselves against herbivores?
iii) How do plants get rid of wastes?
iv) Name the processes by which plants lose excess of water.
i) The wastes stored in some fruits in the form of solid bodies are called “raphides”.
ii) Many plants synthesize chemicals and store them in roots, leaves, seeds, etc. for protection against herbivores.
iii) Waste products may be stored in leaves, bark and fruits. When these dead leaves, bark and ripe fruits fall off from the tree. Then waste products in them are removed.
iv) Plants lose excess of water by transpiration and guttation.
|S.No.||Test||Present level||Normal range|
|A. Blood Test|
|1.||Blood Pressure (BP)||160/90 mm/Hg||120/80 mm/Hg|
|2.||Glucose (Before food)||120- mg/dl||60-100 mg/dl|
|3.||Glucose (After food)||220 mg/dl||160-180 mg/dl|
|4.||Bilirubin||1.0 mg/dl||0.1-0.8 mg/dl|
|B. Urine Test|
|1.||24 hrs protein||150 mg/d ay||100 mg/day|
|2.||Sodium||140 mmol/L||125-250 mmol/L.|
A) Which test is required to know bilirubin?
Blood test is required to know bilirubin.
B) How is the sugar disease confirmed?
In blood test if the glucose levels in blood before and after food are more than the normal, the sugar disease is confirmed.
C) By observing the above report, what would be the other problems faced by that patient?
The blood pressure of the patient 160/90 as the normal is 120/80 mm/Hg.
The Glucose levels in the blood of the patient shows more than the normal before and after food.
So he is suffering from Hypertension and diabetes.
D) What are the organs affected by these problems?
The organsaffected by these problems are heart and kidneys.
Explain the temporary and permanent methods to be adopted for Kidney failure (ESRD) persons.
Temporary method for ESRD persons is Dialysis (Artificial kidney). Permanent method is transplantation of kidney.
- Blood is taken out from the main artery, mixed with an anticoagulant, such as heparin and then pumped in to dialyzer.
- In dialyzer blood flows through cellophane tubes and these tubes are embeded in the dialysing fluid.
- The membrane separates the blood flowing inside the tube and dialysing fluid (same as plasma without nitrogenous waste).
- A functioning kidney is used in transplantation from a donor preferably a close relative.
- The kidney that is received by a recipient must be a good match to his body, to minimise the chances of rejection by the immune system of the recipient.
- Nowadays the process of organ donation helps a lot for kidney failure patients.
What are the accessory excretory organs in human body? How does the liver carry out excretion as a secondary function? (OR)
Write about the accessory excretory organs and their excretory substances in human beings.
|Accessory Excretory Organs||Excretory Materials|
|Lungs||CO2 and Water|
|Skin||Sweat and Metabolic Waste (Sebum)|
|Liver||Bilirubin, Biliverdin, Urochrome|
|Large Intestine (Colon)||Excess of salts of calcium, magnesium and iron are excreted along with faecal matter.|
Excretory functions of Liver:
- Liver acts as detoxification centre of our body. Liver produces bile juice which contain bile pigments which are metabolic wastes of dead R.B.C.
- Bilirubin, Biliverdin and urochrome are the pigments of bile juice.
- Bilirubin, Biliverdin, cholesterol and derivatives of steroids, extra drugs, vitamins and alkaline salts are the wastes produced by liver.
- Urochrome is eliminated through urine.
- Liver also plays a role in the formation of concentrated urine.
Explain the formation of urine in a flow chart.
Dissolved substances of blood like urea, glucose, amino acids, minerals, salts etc., are filtered out in Bowman’s capsule under high filtration pressure.
Glomerular filtrate is called primary urine.
Excreting wastes from the human body not only by kidneys but also by other organs helps you. How do you support it?
- In human body wastes are excreted not only by kidneys but also by other organs.
- Kidney filters blood and eliminates nitrogenous wastes and other harmful things. Filters urea from blood.
- Apart from kidney lungs, skin, liver, intestine, salivary glands and lacrymal glands.
- Lungs remove carbon dioxide and water in respiration.
- Skin excrete wastes in the form of sweat which contains water and certain salts.
- Liver eliminates bile pigments bilirubin and biliverdin through urine.
- Excess salts of calcium, magnesium and iron are excreted by epithellial cells of colon for elimination along with faeces by intestine.
- Eccrine glands present on the forehead, the bottoms of the feet and the palms allow excess water to leave the body.
- Salivary glands and lacrimal glands excrete small amounts of nitrogenous waste through saliva and tears.
Which plants can you get in your village? Among these by-products of which plants do you use in your real life?
- The plants grow or available in our village are Sapota, Coconut, Cassia, Mango, Guava, Borassus plantain, Tobacco, Rauwolfia, Coffee, Neem, Datura, Chrysanthe¬mum, Acacia, Pinus, Vallisneria, Teak, etc.,
- Out of these plants alkaloids are available from the plants like Tobacco, Rauwolfia, Coffee, Neem, Datura and Chrysanthemum. The by-products from these plants are utilised in my real life.
Plant – Use
Tobacco – Insecticide
Rauwolfia serpentina – Medicine for snake bite
Coffee – Central nervous system stimulant
Neem – Antiseptic
Datura – Sedative
Chrysanthemum – Insecticides
- Tannins are the by-products of cassia, acacia. These are used in tanning of leather and in medicines.
- Resin the by-product of Pinus is used in varnishes.
- Gums are extracted from neem and acacia.
They are used as adhesives and binding agents in the preparation of food, medicines.
Write an essay stating the advantages of by-products of plants in our real life.
What are secondary metabolites? Briefly explain their uses.
Not only the food of plants but also their wastes are useful to us. What evidences do you give for it?
- The materials which do not require for normal growth and development are called secondary metabolites. These are the by – products of plants, eg: Alkaloids, Tannins, Resins, Gums and Latex, etc. Though plants produce these chemicals for their own use man found the usage of these chemicals for own benefits. They are generally coloured and fragrant.
- Alkaloids: These are nitrogenous by-products and poisonous. These are stored in different parts of the plants. Common alkaloids in plants and their uses are given in the table.
Alkaloid Plant Part Uses Quinine Cinchona officinalis (Cinchona) Bark Antimalarial drug Nicotine Nicotiana tobacum (Tobacco) Leaves Insecticide Morphine, Cocaine Papaver somniferum (Opium) Fruit Pain killer Reserpine Rauwolfia serpentiana (Snake bite) Root Medicine for snake bite Caffeine Coffea Arabica (Coffee plant) Seed Central nervous system stimulant Nimbin Azadirachta indica (Neem) Seeds, Barks, Leaves Antiseptic Scopolamine Datura stramonium Fruit, flower Sedative Pyrethroids Chrysanthemum sps Flower Insecticides
- Tannins: Tannins are carbon compounds. These are stored in different parts of the plant and are deep brown in colour. Tannins are used in tanning of leather and in medicines, e.g. Cassia, Acacia.
- Resin: Occur mostly in Gymnosperms in specialized passages called resin passages. These are used in varnishes, e.g. Pinus.
- Gums: Plants like Neem, Acacia oozes out a sticky substance called gum. When branches are cut. The gum swells by absorbing water and helps in the healing of damaged parts of a plant. Gums are economically valuable and used as adhesives and binding agents in the preparation of the medicines, food, etc.
- Latex: Latex is a sticky, milky white substance secreted by plants. Latex is stored in latex cells or latex vessels. From the latex of Hevea braziliensis (Rubber plant) rubber is prepared. Latex from Jatropa is the source of bio-diesel.
- Modern chewing gum originally made of chick natural latex from plant.
Blood is purified in kidneys. So many wastes are removed from the blood in nephron of the kidney. Which issue make you surprise in excretory system?
- Kidneys remove nitrogenous waste from our body. They also work towards balancing the amount of vitamins , minerals, fat and protein that are found in the blood. They do this so that our body can easily perform day to day activities.
- Our intestine makes solid waste materials and is excreted through digestive tract.
- Each day our body eliminates around 1.6 to 1.8 liters of urine which contains liquids, minerals and vitamins that are of no use to the body.
- The bladder of a human body is nearly the same size as the average of human brain.
- In one individuals life span the liver can produce around 184.275 kgs of bile (6500 ounces).
- In our lifetime an individual could urinate close to 7,850,000,000 gallons of fluid.
- A really extraordinary fact regarding the excretory system is that upto 400 ml of urine can be held in human bladder.
- Urine contains a high amount of urea which can be used by plants as a source of nitrogen. Because of this diluted urine can be used in gardens and potted plants.
- It is amazing to see that each kidney is made up of approximately more than one million microscopic tubular functional units called nephrons or uriniferous tubules.
What is the structural and functional unit of the excretory system? Draw a neat labelled diagram of that unit.
Nephron is the structural and functional unit of the kidney.
Give an account of excretory system found In different phyla of animal kingdom.
- Different organisms have various excretory systems and organs.
- Following are the excretory system found in various organisms.
Name of the phylum / organism Excretory system / organ Protozoa Simple diffusion from the body surface into the surrounding water. Porifera and coelenterates Water bathes almost all their cells Platyhelminthes Flame cells Nematoda Renette cells Annelids Nephridia Arthropoda Green glands, Maiphigian tubules Mollusca Meta nephridia Echinodermata Water vascular system Reptiles, Birds and Mammals Kidneys
How do plants manage/send out waste products from their body?
- Plants can get rid of excess water by a process like transpiration and guttation.
- Waste products may be stored in leaves, bark and fruits.
- When these dead leaves, bark and ripe fruits fall off from the tree then waste products in them are got rid of.
- Plants get rid of carbon dioxide and oxygen through diffusion.
- Plants release some waste products through roots also.
- Some waste products are deposited near bark as resins or gums.
- In many plants waste products are stored in vacuoles of the cells. Plant cells have comparatively large vacuoles.
In recent days many people are coming forward to donate organs of brain dead people, who met with accidents. How will you appreciate the family members of organ donor?
- In recent days many families are willing to donate organs of brain dead person’s. This is truely significant change in attitude of people.
- Most of the people are burning or burying body after death. Very a few people are would like to see their very dear one’s in other people by donating organs like heart, liver, kidneys, cornea, spleen and bone marrow etc.
- The family members of brain dead are already in great sorrow. They need great courage and so much kindness toward needy patients.
- With nobel decision of that family giving new life to 5 – 7 persons, who has no alternate treatment, other than organ transplantation. In society every one must appreciate their courage, kindness and sympathy. They stood role model to others.
How is the amount of urine produced regulated?
- The amount of urine produced largely depends on the amount of water reabsorbed in the renal tubule.
- The amount of water reabsorbed by the renal tubule largely depends on
the amount of water present in excess in the body need to be removed. If water is abundantly present in the body tissues large quantities of dilute urine is send out of the body. When water is less in quantities in the body tissues a small quantity of concentrated urine is excreted.
- When there is more quantity of dissolved wastes in the body more quantity of water is required to excrete them. So the amount of urine produced increases.
- Deficiency of vasopressin causes excessive, repeated, dilute urination called diabetes insipidus.
Observe the below flow chart. Fill the boxes. Explain to which system this belongs to.
- Loop of Henle
This flow chart belongs to excretory system in human beings. It shows the way how the blood in the kidney moves filtered and urine is excreted.
Explain the external features of kidney in human beings.
- In human beings, there are a pair of bean-shaped, reddish-brown structures in the abdominal cavity attached to dorsal body wall one on either side of the backbone.
- The size of the kidney is 10cm in length, 5 – 6 cm in breadth, and 4cm in thickness.
- Each kidney is convex on the outer side and concave on the inner side.
- The inner side of each kidney has a fissure or hilus for the entry of a renal artery, exit of a renal vein and an ureter.
- Renal artery brings oxygenated blood loaded with waste products and renal vein carries deoxygenated blood.
Describe the excretory system of man.
- The excretory system of man consists of
a) a pair of kidneys
b) ureters and
c) urinary bladder and d) urethra.
- Kidneys are bean shaped and are located in the abdominal region on either side of vertebral column.
- From hilus of each kidney there are a pair of whitish, narrow tubular structures arise. They are known as ureters.
- The ureter travels downwards and open, in the sac like structure called the urinary bladder, which stores urine.
- Urethra is a tube that takes urine from urinary bladder to outside.
- The opening of urinary bladder into urethra is guarded by a ring of muscles or sphincter.
Describe the internal structure of kidney with the help of diagrams. (OR) Describe the structure of nephron with the help of a diagram.
- L.S. of kidney show two distinct regions. Dark coloured outer zone called cortex and pale coloured inner zone called medulla.
- Each kidney is made up of approximately more than one million microscopic and thin tubular functional units called nephrons or uniferous tubules.
- Each nephron has basically two parts. One is malphigian body and other is renal tubule.
- Malphigian body consists of a blind cup shaped broader end of nephron called Bowman s capsule and bunch of fine blood capillaries called glomerulus.
- Glomerulus develops from afferent arteriole and it gives to rise to an efferent arteriole.
- Glomerulus functions as a filtration unit.
- Renal tubule has three parts. They are
- Proximal Convoluted Tubule (PCT)
- Loop of Henle which is ‘U’ shaped and
- Distal Convoluted Tubule (DCT).
- In tubule part reabsorption and secretion takes place. Urine is formed in the renal tubule part of nephron.
- Distal convoluted tubules open into a collecting tube.
- Collecting tube forms pyramids and calyces which open into the pelvis.
- Pelvis leads into the ureter.
Describe the structure of renal tubule with neatly labelled diagram.
- Renal tubule is a specialised tubular structure made up of proximal convoluted tubule, a ‘U’ shaped tube called loop of Henle, and distal convoluted tubule.
- The three tubular components are selectively permeable and only allow specific molecules to pass through them.
- The renal tubule is surrounded by capillaries called peritubular capillaries that arise from the efferent arterioles.
- The substances essential for the body are reabsorbed from the tubules into the peritubular capillaries and the unwanted or toxic molecules are secreted into the lumen of the renal tubule.