NCERT Solutions For Class 10 Science Chapter 7 Control and Coordination

NCERT Books Solutions For Class 10 Science Chapter 7 Control and Coordination

NCERT Solutions For Class 10 Science Chapter 7 Control and Coordination is the first stepping stone for a student in the competitive world. With the introduction of the CBSE Board Exam for class 10 a few years back, this has become an important gateway for a student as based on the results of class 10th a student selects his future stream of Science, Commerce, or Arts.

Takshila Learning provides you with detailed and well explained NCERT Solutions for Class 10 of each chapter of each subject for NCERT Class 10. These NCERT Solutions help you to easily understand every concept so that you can score high in your CBSE Class 10 Board Exams.

Below you can find the NCERT solution for Class 10th Science. You can get a Solution for the all-important question of “Chapter 7 Class 10 Control and Coordination”

Ques 1: What is the difference between reflex and walking?

Answer: Reflex action is involuntary action which means it us not under control of brain only involves spinal cord, it is rapid, thus gives instant response to the stimulus and not affected by our thinking. But walking is a voluntary action controlled by brain, involves central nervous system and spinal cord both and is affected by our thinking.

 

 

Ques 2: What happens at the synapse between two neuron?

Answer: The synapse is tiny gap between two adjacent neurons. This information acquired at the end of the dendritic tip of a nerve cell sets off a chemical reaction that creates an electrical impulse. This impulse travels from the dendrite to the cell body, and then along the axon to its end. At the end of the axon, the electrical impulse  sets off the release of some chemicals. These chemicals cross the gap, or synapse, and a start a similar electrical impulse in a dendrite of the next neuron. This is the process how nervous impulse travel in the body. Similar synapse finally allows delivery of such impulses from neurons to other cells such as muscles or gland.

 

 

Ques 3: Which part of brain maintains posture and equilibrium of the body?

Answer: Cerebellum

 

 

Ques 4 : How do you detect the smell of an agarbatti (incense stick)?

Answer: The agarbatti smell is detected by the olfactory receptor present inside the nose. The action of smell generates the electrical impulse. These impulses are carried to the sensory (forebrain-cerebrum. Thus we detect the smell of agarbatti.

 

 

Ques 5: What is the role of the brain in reflex action?

Answer: Reflex action occurs in spinal cord. The brain and spinal cord constitute the central neurons system. They receive information from all parts of the body to integrate it.

 

 

 

Intext question  (set 2)

Page no. 124

 

Ques 1: What are plant hormones?

Answer: The chemical substances produced in plant which control growth, development and response in plants are called plant hormones.

For example: Auxins, Gibberellins, Cytokinin and Abscisic acid.

 

 

Ques 2: How is the movement of leaves of the sensitive plant different from the movement of a shoot towards light?

Answer:

Movement of leaves of sensitive plants	Movement of shoot towards light
It is not a growth movement	It is a growth movement
It is a nastic movement which does not depend on the direction of the stimulus.	It is a tropic movement which depends on the direction of stimulus.

 

 

Ques 3: Give an example of a plant hormone that promotes growth.

Answer: Auxin: It is responsible for the cell elongation in shoot and also regulates growth.

 

 

Ques 4: How do auxins promote the growth of a tendril around a support?

Answer: Auxins a plant growth hormone present at the tip of tendrils. When the tip of tendrils touches a support, then the auxins present on its tip moves to the side of tip, which is away from the support, so due to more auxin in its tendrils away from the support grows faster.

 

 

Ques 5: Design an experiment to demonstrate hydrotropism.

Answer:

Material required: Seed, a big tray/container, porous water pot, water and sand.

Procedure:

• The tray should be big enough to accommodate porous pot.
• Fill the tray with sand and insert some seed in it.
• Make a pit and insert the porous pot in the sand.
• Fill the porous pot with water and the leave the set up for a week

Observation: After a week when seeds are taken out it is observed that roots grow on the direction of the porous pot. Thus, shows hydrotropism movements in roots.

 

 

 

Intext question  (set 3)

Page no. 125

 

Ques 1: How does chemical coordination take place in animals?

Answer: The chemical coordination in animals takes place by the action of chemical called hormones. They are produced in certain glands in body in very small amount and poured directly in the blood. They are target based means works on particular organs and then organs are called target organs. The hormones control and coordinate various function of the body such as development, growth and sexual changes etc.

 

 

Ques 2: Why is the use of Iodised salt advisable?

Answer: Iodine is necessary for thyroid gland to make thyroxin hormone. Thyroxin regulates carbohydrate, protein and fat, metabolism in the body so as to provide the best balance for growth. Iodine is essential for the synthesis of thyroxin. The deficiency of iodine makes the possibility that we might suffer from goiter.

 

 

Ques 3: how does our body respond when adrenaline is secreted into blood?

Answer: adrenaline is secreted directly in the blood and carried to different parts of the body. The target organs or the specific tissues on which include the heart. As a result the heart beat fast, resulting in supply of more oxygen to our muscles. The blood to the digestive system and skin is reduced due to contraction of muscles around small arteries in these organs. This diverts the blood to our skeletal muscles. The breathing rate also increases because of the contraction of the diaphragm and the rib muscles. All these responses together enable the animal body to be ready to deal with situation. Such animal hormones are part of endocrine system which constitutes a second way to control and coordination in our body.

 

 

Ques 4:  Why are some patients of diabetes treated by giving injections of insulin?

Answer: Diabetes patients as a treatment, they might be taking injections of insulin. This is a hormone which is produced by the pancreas and helps in regulating blood sugar levels. If it is not secreted in proper amounts, the sugar levels in the blood dries is causing many harmful effects.

 

 

Exercise Questions:

Page no. 125

 

Ques 1: Which of the following is a plant hormone?

1. Insulin
2. Thyroxin
3. Oestrogen
4. Cytokinin

Answer: (d) Cytokinin

 

 

Ques 2: The gap between two neuron is called a

1. Dendrite
2. Synapse
3. Axon
4. Impulse

Answer: (b) Synapse

 

 

Ques 3: The brain is responsible for

1. Thinking
2. Regulating the heartbeat
3. Balancing the body
4. (d)All of the above

Answer: (d) all of the above

 

 

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

Answer:  All information from our environment is detected by the specialised tips of some nerve cells. These receptors are usually located in our sense organs such as the inner ear, the nose, the tongue and so on. So, gustatory receptors will detect taste while olfactory receptor will detect smell. We detect that we are touching a hot object by the action of receptors present on various organ or tissue is if olfactory receptors not work properly then we are not able to smell things like perfumes flavour of food.

 

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

Answer:  A neuron consists of three parts;

 

 

Cell body: It is a typical animal cell which contain cytoplasm and a nucleus.

 

Dendrites: A number of long and thin fibres come out from cell body of the neurons, are nerve fibre. The shorter fibre on the cell body of neurons are called dendrites.

 

Axon: The longest fibre on the cell body of neuron is called axon. It has an insulating and protective sheet (or cover) of myelin around it.

 

Function:

The information, acquired at the end of the dendritic tip of a nerve cell, sets off A chemical reaction that creates an electrical impulse.

This impulse travels from the dendrite to the cell body, and then along the axon to its end. At the end of the axon, the electrical impulse sets of the release of some chemicals. These chemicals cross the Gap, or synapse, and start a similar electrical impulse in a dendrite of the next neuron. This is a general scheme of how neuron impulse travel in the body. A similar synapse finally allows delivery of such impulses from neurons to other sales, such as muscles cells or gland.

It is thus no surprise that nervous tissue is made up of an organised network or nerve cells or neurons, is specialised for conducting information via electrical impulses from one part of the body to another.

 

Ques 6: How does phototropism occur in plants?

Answer: Photo means light. The response of plan towards the environment triggers, light we change the direction that plants part grow is called phototropism.

The directional, or dropping, movements can be either towards the light, or away from it so in two different kinds of phototrophic movement, shoot respond by bending to words light while roots Respond by bending away from it.

For example: sunlight bends towards the sun from where the light is coming. This is the response of sunflower towards the plants.

 

 

Ques 7: Which signals will get disrupted in case of a spinal cord injury?

Answer: Reflex actions are in voluntary actions and controlled by the spinal cord thus, get disrupted in case of spinal cord injury.

 

 

Ques 8: How does chemical coordination occur in plants?

Answer: Plants do not have nervous system but still sense the things because of a stimulus such as gravity, Light, chemicals (hormones), water, touch (touch me not plant). Hormones are responsible for the chemical coordination of plants by integrating the behaviour by affecting growth of a plant resulting in movement of the plant part in response to a stimulus. When sunlight falls on the shoot from one side, the auxin hormone causes the shady side of the suit to grow faster, making the shoot and towards sunlight.

 

 

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

Answer:  Controlled movement must be connected to the recognition of various events in the environment, followed by only the correct movement in response. In other words, living organism must use system providing control and coordination. In keeping with the general principles of body organisation in multi-cellular organisms, specialised tissues are used to provide these control and coordination activities.

• Coordination is needed for all human activities like, thinking and behaviour. I was breathing process, hearts beats, we dance, read, write by the action of our nervous system. Our nervous system gets information from surroundings and process it and then respond according to it. The endocrine system (hormonal system) helps in integrating various metabolic activities like a reproduction, development, all reflex actions (cope up with various give up situations).

 

• The hormonal system in plants helps in process of photosynthesis; they need carbon dioxide, water and sunlight. The stomatal opening in leaves opens up to allow in carbon dioxide gas, the water roots bend towards water in the stem grows towards sunlight, the tendrils in climbing plants are supported by the hormonal system of the plant body.

Thus, we have need of control and coordination system in organisms.

 

 

Ques 10: How are involuntary actions and reflex actions different from each other?

Answer: In voluntary actions are not controlled by us they are independent process means there is no stimulus involved in these actions but reflects action is also in-voluntary, but they involve stimulus means functions or respond according to eat.

 

For example: in-voluntary actions: heartbeat, breathing process.

Reflex actions: Stepping out in bright light, changes in size of pupil of eyes.

 

 

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

Answer:

 

Nervous system	Hormonal system
Made up of neurons (nerve cells)	Made up of secretory cells (glands)
Messages transmitted in the form of electrical impulses	Messages transmitted in the form of chemicals called hormones
Messages transmitted along nerve fibre	Messages transmitted along blood stream
Effect of messages usually last for a very short while	Effect of message usually lasts longer
Message travel very quickly	Messages travel more slowly

 

 

Ques 12: What is the difference between the manner in which movement takes place in a sensitive plant and the movement in our legs?

Answer: The movement of sensitive plant leaves takes place due to the sudden loss of water in the pad like swelling (Called pulvini) At the base of all leaves. Pulvini limp Gets drooped and folded due to the loss of water. On the other hand, the movement of our legs take place due to pull in the muscles of legs on the leg bones.