AP 10th Class Biology 6th Lesson Questions and Answers Control and Coordination

AP State Board new syllabus AP Board Solutions Class 10 Biology 6th Lesson Control and Coordination Questions and Answers.

10th Class Biology 6th Lesson Control and Coordination Questions and Answers

10th Class Biology 6th Lesson Questions and Answers (Exercise)

Question 1.
Which of the following is a plant hormone ?
a) Insulin
b) Thyroxin
c) Oestrogen
d) Cytokinin
Answer:
d) Cytokinin

Question 2.
The gap between two neurons is called a
a) dendrite
b) synapse
c) axon
d) impulse
Answer:
b) synapse

Question 3.
The brain is responsible for
a) thinking
b) regulating the heart beat
c) balancing the body
d) all of the above
Answer:
d) all of the above

Question 4.
What is the funtion of receptors in our body? Think of situations where receptors do not work properly. What problems are likely to arise ?
Answer:

• A cell or group of cells that receives stimuli are called receptors.
• Receptors are present in all parts of the body and especially in sense organs like skin, eyes, nose, tongue, etc.
• They detect the signals and then send them to the brain in the form of electrical signals.
• If these receptors are damaged then they will not detect the input which leads to harm to our bodies in dangerous situation.
• For example nasal receptors do not work properly when we have a cold, in this condition we can’t find the smell.
• When receptors don’t work properly we loss the particular sense.

Question 5.
Draw the structure of a neuron and explain its function.

Answer:
Functions of neuron :

• Axon conducts messages away from the cell body.
• Dendrite receives information from axon of another cell and conducts the messages towards the cell body.
• Cell body mainly concerned with the maintenance and growth.

Question 6.
How does phototropism occur in plants ?
Answer:

• Phototropism is a tropic movement in plants which a plant shows in response to a light source.
• It occurs when the plant hormone auxin moves towards the shady part of the stem away from the part which gets light causing more growth in the direction of light.
• That’s why plant bend towards the light, it provides the plant optimize photosynthetic light.

Question 7.
Which signals will get disrupted in case of a spinal cord injury ?
Answer:

• All spinal nerves are mixed nerves. It means they have both sensory and motor fibers.
• In case of a spinal cord injury, the signals coming from the receptors as well as the signals sent to the effectors will be disrupted.
• As both of these signals meet in a bundle in the spinal cord, so, if there is any spinal cord injury then both of these signals will be disrupted.

Question 8.
How does chemical coordination occur in plants ?
Answer:

• Chemical coordination occurs in plants with the help of phytohormones or plant hormones secreted by plants.
• Auxin, cytokinin, gibberellin, and abscisic acid are plant hormones. These hormones regulate the growth and development of the plants.
• They also regulate various metabolic activities in the plants.
• Sometimes they work together and sometimes work oppositely.
• For example auxin and gibberellin work together for plant growth where as auxin and abscisic acid works oppositely.

Question 9.
What is the need for a system of control and coordination in an organism ?
Answer:

• There are various organs and organ systems in a complex organism.
• These organ systems must be carefully controlled and coordinated for the organism’s survival.
• Lack of coordination between these systems can lead to chaos and mismanagement.
• Each and every function performed by an organism, must involve various organs and systems. Coordination is compulsory among the organs.

Question 10.
How are involuntary actions and reflex actions different from each other ?
Answer:

Reflex actions	Involuntary actions
1. Instant responses to a stimulus without the thinking by the brain.	1. It occurs without using will power of an organism.
2. It is controlled by spinal cord.	2. It is controlled by mid brain or medulla oblongata.
3. It is faster in action.	3. It is slower in action.
4. May involve any muscle or a gland.	4. Involves only smooth muscles.
5. Ex : Blinking of eyes, salivation.	5. Ex : Beating of heart, blood circulation.

Question 11.
Compare and contrast nervous and hormonal mechanisms for control and coordination in animals.
Answer:

Nervous mechanism	Hormonal mechanism
1. It is sent as an electrical impulse along axons, and as a chemical across synapse.	1. It is sent as a chemical messenger via blood stream.
2. Information travels rapidly, in milliseconds.	2. Information travels slowly.
3. Information is directed to specific receptors – one or a few nerve fibres, gland cells or other neurons.	3. Information is spread throughout the body by blood from which the target cells or organs pick it up.
4. It gets response immediately.	4. It gets response usually slowly.
5. Its effects are short-lived.	5. Its effects are generally more prolonged.

Question 12.
What is the difference between the manner in which movement takes place in a sensitive plant and the movement in our legs ?
Answer:
Movement in sensitive plants: A sensitive plant’s movement is an involuntary response to stimuli. This coordination is called chemical coordination. It is controlled by hormones.
Movement in legs: Leg movement is a completely voluntary and conscious reaction. It is controlled by the nervous system which is present only in animals.

Movement in plants	Movement in legs
1. Movement in sensitive plants is classified as tropic or nastic movement and is an instinctive response to external or internal stimuli.	1. Leg movement is controlled by the neurological system.
2. It does not require any specific tissues for information transmission.	2. Leg mobility is aided by a sophisticated neural system network that includes the CNS and PNS.
3. There are no specific proteins involved in the movement of the sensitive plant.	3. Actin, myosin, and other proteins aid in the contraction and relaxation of leg muscles to facilitate leg movement.
4. It is the chemical coordination.	4. It is the nervous coordination.

10th Class NS 6th Lesson Questions and Answers (InText)

Page No.50

Question 1.
What is the difference between a reflex action and walking ?
Answer:

Reflex action	Walking
a) Take place without thought.	a) Takes place after thought.
b) Controlled by spinal cord.	b) Controlled by cerebellum.
c) It is involuntary action.	c) It is a voluntary action.

Question 2.
What happens at the synapse between two neurons ?
Answer:

• A synapse is a gap between two neurons.
• At the synapse, the electrical signals are converted into chemicals that can easily cross the gap and pass on to the next neuron where they again get converted into electrical signals.
• Most synapses are chemical; these synapses communicate using chemical messengers.
• Other synapses are electrical; in these synapses, ions flow directly between cells.

Question 3.
Which part of the brain maintains posture and equilibrium of the body ?
Answer:
Cerebellum. This is the part of the hindbrain. It coordinates voluntary muscle movements and helps to maintain posture, balance, and equilibrium.

Question 4.
How do we detect the smell of an agarbatti (incense stick) ?
Answer:

• Smell molecules from incense sticks diffuse into the air and reach the nose.
• These are detected by the olfactory receptors present in the nose.
• The receptors send the signal to the olfactory lobe present in the fore-brain where it is analyzed and reacted upon.

Question 5.
What is the role of the brain in reflex action ?
Answer:

• In a reflex action, the brain plays no part.
• The spinal cord, which reacts without thinking about how to respond to stimuli, is in charge of these automatic actions.
• The brain is not involved in a reflex action as it is an involuntary action that does not require thinking.

Page No.54

Question 6.
What are plant hormones ?
Answer:
Plant hormones are chemical compounds present in very low concentration in plants. They are auxins, Gibberellins. Cytokinins, Abscisic acid, Ethylene.

Question 7.
How is the movement of leaves of the sensitive plant different from the movement of a shoot towards light?
Answer:
The movement of leaves of the sensitive plant Mimosa pudica or “touch me not” occurs in response to touch or contact stimuli is a nastic movement.This is done by plant cells by changing the amount of water in leaves. This movement is independent of growth. The movement of shoot towards light is known as phototropism.

Aerobic respiration	Anaerobic respiration
1. It is a non directional stimulus in plants.	1. It is a directional stimulus in plants.
2. The stimulus for the movement is touch.	2. The stimulus for the movement is light.
3. The movement is called nastic movement.	3. The movement is called tropic movement.
4. It is caused by sudden loss of water from the pulvinus of leaves.	4. It is caused by the unequal growth on the two sides of the shoot.
5. It is very fast process.	5. It is very slow process.

Question 8.
Give an example of a plant hormone that promotes growth.
Answer:
Plant Growth Promoters – They promote cell division, cell enlargement, flowering, fruiting and seed formation. Examples are auxins, gibberellins and cytokinins.

Question 9.
How do auxins promote the growth of a tendril around a support ?
Answer:

• Auxin is a plant hormone which is synthesized at the tip of the shoot.
• It helps the cell grow longer.
• When a tendril comes in contact with a support, auxin stimulates faster growth of the cells on the opposite side.
• That’s why the tendril forms a coil around the support.

Question 10.
Design an experiment to demonstrate hydrotropism.
Answer:

• Fill a conical flask with water.
• Cover the neck of the flask with a wire mesh.
• Keep two or three freshly germinated bean seeds on the wire mesh. Take a cardboard box which is open from one side.
• Keep the flask in the box in such a manner that the open side of the box faces light coming from a window.
• After two or three days, you will notice that the shoots bend towards light and roots away from light.
• Now turn the flask so that the shoots are away from light and the roots towards light. Leave it undisturbed in this condition for a few days.
• We noticed that the old parts of the shoot changed their direction towards light, which is called phototropism.

Page No. 58

Question 11.
How does chemical coordination take place in animals ?
Answer:

• Chemical coordination takes place in animals with the help of hormones.
• Hormones are the chemical fluid that are secreted by the glands of the endocrine system.
• Hormones regulate the over all growth and development of the animals.
• Pituitary, thyroid, adrenal glands are some endocrine glands in human.

Question 12.
Why is the use of iodised salt advisable ?
Answer:

• Iodine is needed to make the thyroid hormones thyroxine and triidothyronine.
• This hormone regulates fat, protein and carbohydrate metabolism in our bodies.
• If the quantity of iodine in food is less than required, then the neck will swell up due to the enlargement of the thyroid gland.
• This deficiency disease is known as goiter. Therefore to avoid goiter iodized salt is advised.

Question 13.
How does our body respond when adrenaline is secreted into the blood ?
Answer:

• Adrenal glands, also known as suprarenal glands are small triangular-shaped glands located on top of both kidneys.
• Adrenal glands produce hormones Adrenaline ,it triggers the body’s fight-or-flight response.
• This adrenaline hormone increases our ‘heart beat’, ‘breathing rate’, ‘blood flow into muscles’ and causes the liver ‘to put more stored glucose into our blood’.
• When secreted in large amounts it speeds up the heartbeat and hence supplies more oxygen to the muscles.
• The breathing rate also increases due to contractions of diaphragm and rib muscles.
• It also increases blood pressure. All these responses enable the body to deal with any stress or emergency.

Question 14.
Why are some patients of diabetes treated by giving injections of insulin?
Answer:
Diabetes is caused by high blood sugar levels . Diabetic patients are treated by giving injections of insulin as it lowers the blood sugar level by controlling the metabolism of sugar.

AP Board Solutions Class 10 Biology Chapter 6 Questions and Answers (Lab Activities)

Activity – 6.1

1. Write an activity to know about the taste of food item in different situations.

• Put some sugar in your mouth. How does it taste? The sugar is sweet.
• Block your nose by pressing it between your thumb and index finger. Now eat sugar again. Is there any difference in its taste?
• Yes,its different. I can’t find the sugar such a sweet. I can’t find the taste.
• While eating lunch, block your nose in the same way and notice if you can fully appreciate the taste of the food you are eating ?
• By blocking the nose I can’t find the food taste, I think there is a relation between nose and tongue.

Activity – 6.2

2. Conduct and write an activity to show the response of the plant to the direction of light.

• Fill a conical flask with water.
• Cover the neck of the flask with a wire mesh.
• Keep two or three freshly germinated bean seeds on the wire mesh.
• Take a cardboard box which is open from one side.
• Keep the flask in the box in such a manner that the open side of the box faces light coming from a window.

• After two or three days, you will notice that the shoots bend towards light and roots away from light.
• Now turn the flask so that the shoots are away from light and the roots towards light. Leave it undisturbed in this condition for a few days.
• Have the old parts of the shoot and root changed direction? Yes there is a change of direction in shoot and root.
• Are there differences in the direction of the new growth?
• Again the shoots bend towards light and roots away from light.
• What can we conclude from this activity?
• The shoots always bend towards light and roots away from light.

Activtiy -6.3

3. How do you find the endocrine glands in our body with help of achart.

Identify the endocrine glands mentioned in the figure.
I observe the following endocrine glands in the figure.

• hypothalamus
• pituitary
• thyroid
• parathyroid
• adrenal
• pineal body
• ovaries
• testes
• thymus
• pancreas

Some of these glands have been listed in Table 6.1 and discussed in the text. Consult books in the library and discuss with your teachers to find out about other glands.

1. Hypothalamus : Hypothalamus plays an important role in the release of many hormones. For example, when the level of growth hormone is low, the hypothalamus releases growth hormone releasing factor which stimulates the pituitary gland to release growth hormone. The hypothalamus secretes hormones that stimulate or suppress the release of hormones in the pituitary gland, in addition to controlling water balance, sleep, temperature, appetite, and blood pressure.

2. Parathyroids : The parathyroid glands lie just behind the thyroid glands in the neck. The parathyroid glands produce parathyroid hormone, which increases levels of calcium in the blood. The parathyroid glands are small pea-sized glands located in the neck just behind the butterfly-shaped thyroid gland.

3. Pineal body : Pineal gland, also called the pineal body or epiphysis cerebri, is a tiny gland in your brain that’s located beneath the back part of the corpus callosum. It’s a part of your endocrine system and secretes the hormone melatonin.

Activity – 6.4

4. Hormones are secreted by endocrine glands and have specific functions. Complete table based on the hormone, the endocrine gland or the functions provided.

Some important hormones and their functions

S.No.	Hormone	Endocrine Gland		Functions
1.	Growth hormone	Pituitary gland		Stimulates growth in all organs
2.	___________	Thyroid gland		Regulates metabolism for body growth
3.	Insulin	___________		Regulates blood sugar level
4.	Testosterone	Testes		___________
5.	___________	Ovaries		Development of female sex organs, regulates menstrual cycle etc.
6.	Adrenaline	Adrenal gland		___________
7.	Releasing hormones	___________		Stimulates pituitary gland to release hormones

Answer:

S.No.	Hormone		Endocrine gland		Functions
1.	Growth Hormone		Pituitary gland		Stimulates growth in all organs
2.	Thyroxine		Thyroid gland		Regulates metabolism for body growth.
3.	Insulin		Pancreas		Regulates blood sugar level
4.	Testosterone		Testes		Changes during puberty. Develop­ment of male sex organs, behaviour etc.
5.	Oestrogen		Ovaries		Development of female sex organs, regulates menstrual cycle, etc.
6.	Adrenaline		Adrenal		Prepares body to cope with emergency situations.
7.	Releasing hormones		Hypothalamus		Stimulates pituitary gland to release hormones.