NIOS Class 10 Science and Technology Chapter 23 Control and Coordination

NIOS Class 10 Science and Technology Chapter 23 Control and Coordination Solutions to each chapter is provided in the list so that you can easily browse through different chapters NIOS Class 10 Science and Technology Chapter 23 Control and Coordination and select need one. NIOS Class 10 Science and Technology Chapter 23 Control and Coordination Question Answers Download PDF. NIOS Study Material of Class 10 Science and Technology Notes Paper 212.

NIOS Class 10 Science and Technology Chapter 23 Control and Coordination

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Also, you can read the NIOS book online in these sections Solutions by Expert Teachers as per National Institute of Open Schooling (NIOS) Book guidelines. These solutions are part of NIOS All Subject Solutions. Here we have given NIOS Class 10 Science and Technology Chapter 23 Control and Coordination, NIOS Secondary Course Science and Technology Solutions for All Chapters, You can practice these here.

Control and Coordination

Chapter: 23


1. Can you think of a real-life example, when team work helped you to achieve something that you could not have done by yourself? Please write about this incidence in 3-5 sentences.

Ans: There is no single correct answer. There may be diverse examples. For instance, in farming, a group of people till the land, another group sows the seeds, someone else takes care of the crops and only then everyone enjoys the bounty of a good harvest.

2. Give one example of coordination of a process taking place in our body which is brought about by both the nervous system and hormonal system.

Ans: Secretion of digestive juices.


1. The structural and functional unit of nervous system is (encircle the correct alternative out of the following)

(a) Nephron. 

(b) Neuron. 

c) Synapse. 

(d) Axon.

Ans: (a) Nephron. 

2. Consider that you are passing by a garbage disposal area and you immediately cover your nose. Arrange the events below in a logical order by marking them from 1 to 5 to trace the events that happen in the nervous system from detection of foul smell (stimulus generation) to covering your nose (response).

(i) At the end of the axon, electrical impulse releases chemicals. 

(ii) Stimulus received on the dendritic cells of a neuron sets off a chemical reaction that creates an electrical impulse. 

(iii) Electrical impulse transmitted through cell body and axon

(iv) The chemicals cross the synapse and reach the next neuron. Similarly, the electrical impulse crosses several neurons. 

(v) Finally, the impulse is delivered from neuron to the gland that helps in recognition of the foul smell and muscle cells that help in covering the nose.

Ans: The sequence should be: ii, iii, i, iv, v

3. With the help of a suitable example, explain the term ‘stimulus.’

Ans: A stimulus is an agent or an environmental change which can initiate a response in the body. The stimuli can be of several types. It could be physical (touch, prick, pressure), auditory, chemical, radiant (light), heat or cold, or electrical.


Fill in the blanks:

(i) The central nervous system consists of ________ and _____________.

Ans: Brain and spinal cord.

(ii) The two functions of the cerebrum are _________ and ____________. 

Ans: Intelligence and consciousness.

(iii) The major function of cerebellum is to maintain ________ of the body. 

Ans: Balance.

(iv) The ________________ part of brain controls the activity of all internal organs of our body. 

Ans: Medulla/ medulla oblongata.

(v) The outer and inner region of the cerebrum are composed of _______ and ___________ matter respectively.

Ans: Gray matter, white matter


1. Name the two types of reflexes.

Ans: Natural reflex and conditioned reflex.

2. Given below are the different components of a reflex arc in a haphazard manner. Arrange them in the correct order in the space provided below: Sensory neuron, Effector, Stimulus, CNS, Receptor, Response, Motor neuron.

Ans: Natural reflex and conditioned reflex.

3. Now that you are aware of the well-thought out voluntary actions that are coordinated by the cerebrum and immediate response actions or reflex actions, co-ordinated by the spinal cord, try to identify whether the following situations.

Ans: Correct response has been provided in italics for the column on ‘Appropriate Action.’ However, there is no single correct reason for the choice that the learner makes. The evaluator needs to keep in mind that the learner is providing logical reasons for their choice. 


1. How many pairs of cranial nerves are present in our body?

Ans: 12 pairs.

2. Name the two parts of autonomic nervous system.

Ans: Sympathetic and parasympathetic.


1. Fill in the blanks:

(i) A hormone is transported by the ________ to the target organ. 

Ans: Blood.

(ii) Hypoactivity of thyroid gland causes  ________ leading to cretinism in young children.

Ans: Goitre.

(iii) Pancreas secretes two hormones, which help in the ________ of glucose in our body.

Ans: Metabolism.

2. Each of the following statements has one correct response. Please choose the correct option and encircle it. 

(i) If a pathologist were to collect a hormone, where would it be collected from?

(a) Blood. 

(b) Brain. 

(c) Specific endocrine gland.

(d) Any part of the body.

Ans: (a) Blood. 

(ii) Hyperactivity of the pituitary gland causes: 

(a) Dwarfism.

(b) Gigantism.

(c) Cushing’s disease.

(d) Cretinism. 

Ans: (c) Cushing’s disease.

(iii) The neurons that carry impulses from sense organs to the brain or spinal cord are: 

(a) Sensory neuron.

(b) Motor neuron.

(c) Association neuron.

(d) Connecting neuron.

Ans: (a) Sensory neuron.

(iv) The parts of a reflex are connected to: 

(a) Brain.

(b) Spinal cord. 

(c) Both brain and spinal cord. 

(d) A synapse. 

Ans: (c) Both brain and spinal cord.

(v) Two neurons are connected to each other through: 

(a) Their axons. 

(b) Their dendrons. 

(c) The dendrites of the first neuron and the dendrites of the second one. 

(d) Synapse. 

Ans: (d) Synapse. 

(vi) An axon is: 

(a) A nerve fibre 

(b) A bundle of dendrites.

(c) A bundle of nerve fibres. 

(d) The sheath of a nerve fibre. 

Ans: (d) The sheath of a nerve fibre. 

(vii) An individual reported to the neuro-physician with a body temperature much higher than normal. After several investigations, the neuro- physician diagnosed that a tumour in a specific area of the brain was causing this symptom. Where do you thing the tumour may have been located? 

(a) Cerebrum.

(b) Cerebellum. 

(c) Hypothalamus. 

(d) Diencephalon. 

Ans: (c) Hypothalamus.

(viii) Where is the subconscious mind located? 

(a) Thalamus. 

(b) Hypothalamus. 

(c) Cerebellum. 

(d) Cerebrum. 

Ans: (d) Cerebrum. 

(ix) Hyposecretion of insulin causes: 

(a) Diabetes.

(b) Goitre. 

(c) Cretinism. 

(d) Gigantism.

Ans: (a) Diabetes.

(x) Which part of our brain helps in maintaining the balance of our body? 

(a) Cerebrum. 

(b) Diabetes. 

(c) Medulla. 

(d) Hypothalamus. 

Ans: (b) Diabetes.

(xi) Sudha likes to sleep in and someone always has to wake her up in the morning. However, during exams she is able to get up without an alarm or any other help. Which part of the nervous system helps her to deal with this situation?

(a) Parasympathetic nervous system. 

(b) Medulla. 

(c) Sympathetic nervous system. 

(d) Cerebrum.

Ans: (c) Sympathetic nervous system. 


A. Tick the correct answer of the following.

1. The three protective coverings over the brain are also called:

(A) Membranes. 

(B) Layers. 

(C) Meninge. 

(D) Sheaths. 

Ans: (C) Meninge. 

2. Which part of the brain controls the body temperature? 

(A) Cerebrum.

(B) Cerebellum. 

(C) Hypothalamus. 

(D) Medulla oblongata.  

Ans: (C) Hypothalamus. 

3. The spinal cord is extended from the medulla up to the whole length of the vertebral column and lies within the: 

(A) Neural canal. 

(B) Vertebral canal. 

(C) Spinal canal. 

Ans: (C) Spinal canal. 

4. Which one of the following hormones is secreted by the pancreas?

(A) Prolactin.

(B) Thyroxin.

(C) Adrenalin. 

(D) Insulin.

Ans: (D) Insulin.

B. Answer briefly:

1. What is the nature of the membranes covering the brain? What is the name of the fluid that fills the space between these membranes? What is its role?

Ans: Three layers of membranes known as meninges protect the brain and spinal cord. The delicate inner layer is the pia mater. The middle layer is the arachnoid, a web-like structure filled with fluid that cushions the brain. The tough outer layer is called the dura mater.

The subarachnoid space is a space between your arachnoid mater and pia mater. It’s filled with cerebrospinal fluid.

Its roles are mentioned below:

(i) Cushioning: CSF acts as a shock absorber, protecting the brain from impacts and bumps to the head.

(ii) Buoyancy: It helps to support the weight of the brain within the skull.

(iii) Waste Removal: CSF carries away waste products from the brain and spinal cord.

(iv) Chemical Balance: It helps to regulate the chemical environment around the brain.

(v) Infection Protection: CSF acts as a barrier against the spread of infection.pen_spark

2. Describe the three regions of the brain.

Ans: Three regions of the brain are mentioned below:

(i) Forebrain: The largest and most complex part of the brain, responsible for higher-order functions like thinking, planning, decision-making, and sensory processing. It includes the cerebrum, which is further divided into two hemispheres (left and right), and the diencephalon, which contains structures like the thalamus and hypothalamus.

(ii) Midbrain: A smaller region located between the forebrain and hindbrain. It acts as a relay centre for information travelling between the upper and lower parts of the brain. The midbrain also plays a role in regulating movement, vision, hearing, and sleep.

(iii) Hindbrain: Located at the back of the brain, the hindbrain is responsible for basic bodily functions like breathing, heart rate, digestion, and balance. It consists of the medulla oblongata, pons, and cerebellum.

3. Differentiate between the following pairs of terms: 

(i) Sensory nerve and motor nerve. 

Ans: The sensory nerve carries the signal from the different body parts then it transfers this signal to the main if CNS whereas the motor does its reverse works it transfer the action reaction from CNS to the different part of the body.

(ii) Cerebrum and cerebellum. 


It Consists of 80% of the brainThe doesn’t consist of that amount as Compared to small
t helps in intelligence of brain.Its control blood pressure 

(iii) Sympathetic and parasympathetic nervous system.

Ans: The sympathetic nervous system works in the sudden like instant action and reaction of the body whereas the parasympathetic nervous system works in a slow way and consumes more energy.

4. Define the following terms: 

(i) Receptor. 

Ans: Through the receptors the sense of the different object is felt by us or the body and works accordingly.

(ii) Synapse.

Ans: A synapse is a small gap at the end of a neuron that allows a signal to pass from one neuron to the next

(iii) Hormone.

Ans: Hormones are chemical substances that act like messenger molecules in the body. After being made in one part of the body, they travel to other parts of the body where they help control how cells and organs do their work.

(iv) Neuron.

Ans: Neurons are nerve cells that send messages all over your body to allow you to do everything from breathing to talking, eating, walking, and thinking. Until recently, most neuroscientists (scientists who study the brain) thought we were born with all the neurons we were ever going to have.

(v) Impulse. 

Ans: The signal of the different activity is transfer through the neuron and this system is known as the impulse which is like the signal transfer.

(vi) Stimulus.

Ans: Stimulus is an event or any change in the external environment that evokes a specific functional reaction in an organ or tissue. stimulus can be internal or external.

(vii) Effecto.

Ans: The stimulus acts differently which then reflects by the effector. This effect does a different reflection.

5. Given below is a table regarding various hormones secreted by the pituitary gland, and functions of these secretions. Fill in the blanks (1 to 4);

Hormones secreted                       Functions

(i) Somatotropic hormone ______________(1)____________.

(ii) __________(2)____________ Helps in the metabolism of glucose in our body.

(iii) Thyroid hormone ____________(3)__________ .

(iv) __________(4)_____________ In males it stimulates the secretion of testosterone. 


Hormones secreted  Functions
Somatotropic hormonesGrowth of the body is regulated.
Thyroxinhelps in the metabolism of glucose inour body
thyroid hormonesControl basal metabolic rate
Luteinizing hormonesIn males it stimulates the secretion oftestosterone.

6. Imagine that you did not score good marks in your science exam. Do you?

(a) Tear the mark sheet and not let your parents know about it?

(b) Decide that you are not a good student and cannot study science any further?  

(c) Discuss your mistakes with the teacher and ask for help from the teacher or another student who has done well and is willing to help you.

Please choose one of the three options above and provide two reasons for your choice

Ans: Do yourself.

7. Imagine that you have gone out with three friends. One of them starts smoking and offers the cigarette to the rest of you. One of your friends accepts the offer hesitatingly and also encourages you to try smoking. One amongst you refuses to smoke and says that he did not know that he was in bad company. This person leaves the group in a huff. You also do not want to smoke but at the same time you have been friends with this group for many years now and would like to continue your friendship.

Please describe in 2-4 sentences how you will communicate with your friends in an attempt to save your friendship without accepting their offer to smoke.

Please note: There is no single correct answer. The learner needs to demonstrate use of assertive communication skills.

Ans: If a friend is addicted to smoking that’s not mean that we left that friend. If we remain in our position strictly then no one can make up for going in wrong ways. And we should make friends so that he must stop smoking day by day.

8. After a week, you go out again with the two friends who had asked you to try smoking a cigarette. This time they tell you that it is smart or stylish to smoke and in order to be part of the group, you should also smoke. Would you like to continue/ not continue being friends with them?

Please state your decision and provide at least two reasons for your decision.

Please note: There is no single correct answer. The purpose of this activity is to enable the learner to appreciate that friends never pressurise to do things that someone is uncomfortable with. The learner also needs to realise that exploitative relationships, including friendships should be terminated.

Ans: After making him understand that at this age smoking is injurious to health, but again he does it then I should not be trying to remain a friend of mine or her as he doesn’t seem to come in a good way.

9. When a barefoot person accidentally steps on a pin, what will be her/ his immediate response? Explain how this reaction is processed by the nervous system?

Ans: As when a bare foot person accidentally steps a pin in his feet then the receptor get this signal and transfers to the central nervous system and then after this the effector transfers this signal and we keep our legs from that.

10. Give one function performed by each of the following: 

(i) Cerebrum. 

Ans: The largest part of the brain.

(ii) Cerebellum. 

Ans: Different involuntary activity is maintained by this.

(iii) Hypothalamus.

Ans: The hormonal concentration goes on by this.

(iv)  Medulla oblongata. 

Ans: The medulla oblongata plays a critical role in transmitting signals between the spinal cord and the higher parts of the brain and in controlling autonomic activities, such as heartbeat and respiration

(v) Cerebrospinal fluid.

Ans: protect the spinal cord and work as resistance.

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