Question 1

Question 2(b)Assertion (A): Cerebellum enables us to remember, think and reason.Reason (R): It is the largest portion of the brain and occupies the whole central area.Both A and R are true.Both A and R are false.A is true and R is false.A is false and R is true.

Accepted Answer

Both A and R are false.Explanation — The main function of cerebellum are muscular coordination and body balance. Cerebrum, the largest portion of the brain, is the seat of intelligence, consciousness and will power. Hence, it enables us to remember, think and reason. Therefore both the Assertion and the Reason are incorrect.

Question 2

Question 1(a)Differentiate between the following pairs of terms on the basis of what is indicated within the brackets :Stimulus and response (definition)

Accepted Answer

Difference between Stimulus and Response on the basis of definition:StimulusResponseAny change in the environment that usually results in change in the activity of the body.The activity of the body due to the stimulus.

Question 3

Question 1(c)Differentiate between the following pairs of terms on the basis of what is indicated within the brackets :Motor nerve and Sensory nerve (function)

Accepted Answer

Difference between Motor nerve and Sensory nerve on the basis of their function:Motor NerveSensory NerveMotor nerve carries impulses from the brain and spinal cord to the muscles and glands.Sensory nerve carries impulses from the sense organs to the spinal cord or brain.

Question 4

Question 1(e)Differentiate between the following pairs of terms on the basis of what is indicated within the brackets :Cerebrum and Medulla oblongata (function)

Accepted Answer

Difference between Cerebrum and Medulla oblongata on the basis of their function:CerebrumMedulla oblongataThe cerebrum is the seat of intelligence, consciousness and will power. It controls all the voluntary activities.Medulla oblongata controls the activities of the internal organs.

Question 5

Question 1(f)Differentiate between the following pairs of terms on the basis of what is indicated within the brackets :Cerebrum and Spinal cord (arrangement of white and grey matter)

Accepted Answer

Difference between Cerebrum and Spinal cord on the basis of arrangement of white and grey matter:CerebrumSpinal cordIn Cerebrum, the outer portion contains grey matter and inner portion contains white matter.In Spinal cord, the inner part contains grey matter and the outer part contains white matter.

Question 6

Question 2Draw a neat and labeled diagram of a neuron and answer the following questions :(a) What are the two main parts of a neuron?(b) Is this structure unicellular or multicellular?(c) Which part of the neuron contains nucleus?(d) Name the two parts of the human body where neurons are found abundantly.(e) How are neurons significant to us?

Accepted Answer

Labeled diagram of a neuron is shown below:(a) Axon and Cyton(b) Unicellular(c) Cyton(d) Brain and Spinal cord(e) Neurons are significant to us as they are the fundamental building blocks of the nervous system. Neurons carry impulses between sense organs and brain or spinal cord as well as between themselves. They keep us informed about the outside world and bring about control and coordination in our body. They also help in regulating our involuntary activities.

Question 7

Question 3With the help of a suitable example, describe reflex action.

Accepted Answer

The peripheral nervous system and spinal cord together control certain actions where the brain is not involved, e.g. when we touch a hot object or get pricked by a pointed object, we instantly remove our hand, without thinking about it. Such an action is called a reflex action.

Question 8

Question 4(a)Briefly differentiate between the following by giving examples:Voluntary and involuntary action.

Accepted Answer

Difference between Voluntary and involuntary action is given below:Voluntary ActionInvoluntary ActionVoluntary actions occur knowingly.Involuntary actions occur unknowingly.Cerebrum controls voluntary actions.Medulla oblongata and Spinal cord controls involuntary actions.Eating apple, watching TV are examples of voluntary actions.Breathing, beating of heart are examples of involuntary actions.

Question 9

Question 4(b)Briefly differentiate between the following by giving examples:Inborn and acquired reflexes.

Accepted Answer

Difference between Inborn and acquired reflexes is given below:Inborn ReflexesAcquired ReflexesNo previous experience or learning is required for inborn reflexes.Acquired reflexes develop with experience and learning during the lifetime.Blinking, coughing, sneezing, vomiting are examples of inborn reflexes.Typing on the keyboard, playing a musical instrument are examples of acquired reflexes.

Question 10

Question 1(e)Peripheral nervous system consists of different types of nerves which connect the central nervous system to all parts of the body. Cranial nerves, spinal nerves, sympathetic and parasympathetic nerves are all connected to different parts of the body. Which of the following does not belong to cranial nerves ?Olfactory nervesAuditory nervesOptic nervesSympathetic nerves

Accepted Answer

Sympathetic nervesReason — Cranial nerves emerge from the brain. Some of the cranial nerves are — the olfactory (for nose), optic (for eyes) and auditory (for ears). While cranial nerves are a part of Somatic nervous system, Sympathetic nerves are a part of Autonomic nervous system.

Question 11

Question 3(a)Write one important role of Cerebrum.

Accepted Answer

Intelligence and memory.

Question 12

Question 3(b)Write one important role of Cerebellum.

Accepted Answer

Muscular Coordination.

Question 13

Question 3(c)Write one important role of Medulla oblongata.

Accepted Answer

Breathing and digestion.

Question 14

Question 3(d)Write one important role of Receptors.

Accepted Answer

Receive the stimulus.

Question 15

Question 3(e)Write one important role of Spinal cord.

Accepted Answer

Control reflexes below neck.

Question 16

Question 4Write the specific terms/structures for the ‘pathway of a reflex arc’ in a proper logical sequence, starting with stimulus and ending with response/reflex action.

Accepted Answer

'Pathway of a reflex arc' is shown below:

Nervous System

Assertion Reason Type Questions

Long Answer Questions

Objective Type Questions

Short Answer Questions