NCERT Exemplar Class 11 Biology Solutions Chapter 21 Neural Control and Coordination

Access NCERT Exemplar Class 11 Biology Chapter 21 (Multiple Choice Questions)

The detailed answers to the MCQ solutions are given below:

Question:1

Chemicals that are released at the synaptic junction are called
(a) Hormones
(b) Neurotransmitters
(c) Cerebrospinal fluid
(d) Lymph

Answer:

The answer is option (b), Neurotransmitters

Explanation: Neurotransmitters facilitate the transmission of impulses at the synaptic junction.

Question:2

The potential difference across the resting membrane is negatively charged. This is due to the differential distribution of the following ions
a. Na⁺ and K⁺ ions
b. CO³⁺⁺ and Cl^- ions
c. Ca⁺⁺ and Mg⁺⁺ ions
d. Ca⁴⁺ and Cl^- ions

Answer:

The potential difference across the resting membrane is negative. This is due to the differential distribution of Na+ and K+ ions.

Question:3

Resting membrane potential is maintained by
(a) Hormones
(b) Neurotransmitters
(c) Ion pumps
(d) None of the above

Answer:

The answer is option (c) Ion pumps

Explanation: In a resting neuron, there exist concentration gradients across the resting membrane for Na+ & K+. The ionic gradients are maintained by Ion pumps (Na-K pumps).

Question:4

The function of our visceral organs is controlled by

(a) Sympathetic and somatic neural system
(b) Sympathetic and parasympathetic neural system
(c) Central and somatic nervous system
(d) None of the above

Answer:

The answer is option (b), the Sympathetic and parasympathetic neural system

Explanation: Option (a) is related to the peripheral nervous system, and option (c) is not related to the regulation of visceral organs. But option (b) controls the functioning of visceral organs.

Question:5

Which of the following is not involved in the Knee reflex?
(a) Muscle spindle
(b) Motor neuron
(c) Brain
(d) Inter neurons

Answer:

The answer is option (c) Brain

Explanation: Muscle spindles, motor neurons, and interneurons are part of the reflex arch, unlike the brain.

Question:6

An area in the brain that is associated with strong emotions is
(a) Cerebral cortex
(b) Cerebellum
(c) Limbic system
(d) Medulla

Answer:

The answer is option (c) Limbic system

Explanation: The limbic system, along with the hypothalamus, is associated with emotions.

Question:7

Mark the vitamin present in Rhodopsin
(a) Vit A
(b) Vit B
(c) Vit C
(d) Vit D

Answer:

The answer is option (a) Vit A

Explanation: Rhodopsin is related to eye vision, and vitamin A is directly related to vision.

Question:8

Human eyeball consists of three layers, and it encloses
(a) Lens, iris, optic nerve
(b) Lens, aqueous humor, and vitreous humor
(c) Cornea, lens, iris
(d) Cornea, lens, optic nerve

Answer:

The answer is option (b) Lens, aqueous humor, and vitreous humor

Explanation: The Human eyeball has three layers- sclera, choroid, and retina. These three layers enclose the lens, aqueous humor, and vitreous humor.

Question:9

Wax gland present in the ear canal is called
(a) Sweat gland
(b) Prostate gland
(c) Cowper's gland
(d) Sebaceous gland/ ceruminous gland

Answer:

The answer is option (d) Cowper's gland

Explanation: Other glands are not related to the ear.

Question:10

The part of the internal ear responsible for hearing is
(a) Cochlea
(b) Semicircular canal
(c) Utriculus
(d) Sacculus

Answer:

The answer is option (a) Cochlea

Explanation: The Cochlea is the inner part of the ear that facilitates hearing.

Question:11

The organ of Corti is a structure present in
(a) External ear
(b) Middle ear
(c) Semi-circular canal
(d) Cochlea

Answer:

The answer is option (d) Cochlea

Explanation: The Organ of Corti is present at the sensory ridge present at the basilar membrane, which is present in the cochlea.

Find Answers to the NCERT Exemplar Class 11 Biology Chapter 21 (Long Questions)

Question:1

Explain the process of the transport and release of a neurotransmitter with the help of a labelled diagram showing a complete neuron, axon terminal, and synapse.

Answer:

Neurotransmitters help in the transmission of impulses at the junction between two neurons, called a chemical synapse. In the synapse, there exist synaptic vesicles in the axon terminal called a synaptic knob. These vessels contain neurotransmitters. The impulses from the nerves reach the axon terminal and travel through it as electrical signals. When the impulse reaches the end of the axon, it picks up the neurotransmitters present in it and attaches them to the chemo-receptors that are present on the dendrite membrane of the next neuron. This attachment of chemicals (acetylcholine) with chemo-receptors leads to depolarization of the membrane, generating a nerve impulse across the nerve fiber. Acetylcholine is inactivated and hydrolyzed by the enzyme found in the postsynaptic membrane- acetylcholinesterase. The hydrolyses facilitate the repolarization of the membrane.

Question:2

Name the parts of the human forebrain, indicating their respective functions.

Answer:

The forebrain comprises the cerebrum, thalamus, and hypothalamus. Their functions are as follows:

Cerebrum:

It has motor and sensory functions.

Thalamus:

It helps in coordination and motor signalling.

Hypothalamus:

It helps in maintaining the body temperature and also the regulation of feelings like hunger and thirst.

Question:3

Explain the structure of the middle and internal ear with the help of a diagram.

Answer:

The structure of the human ear is divided into three parts- the external ear, the middle ear, and the internal ear.

Structure of the Middle Ear: The middle ear is composed of three bones or ossicles- malleus, incus, and stapes. All three bones are attached to each other in a chain-like manner. The malleus is attached to the tympanic membrane, and the stapes is attached to a membrane of the cochlea called the oval window. The tympanic membrane is the one that separates the middle ear from the external ear. It is also called the eardrum. Not only that, but it also helps in catching the sound waves and transmitting them to the bony ossicles. From the bony ossicles, the waves are transferred to the inner ear. The eustachian tube connects the pharynx to the middle ear. tympanic membrane and bony ossicles. The tympanic membrane separates the middle ear from the external ear, and the middle ear is connected to the pharynx by the eustachian tube.

Structure of Inner Ear: The Inner ear is composed of a fluid-filled chamber called the labyrinth. It is divided into two parts- an outer bony labyrinth and an inner membranous labyrinth. The bony labyrinth consists of channels filled with a fluid called endolymph. The portion that is coiled in the labyrinth is the cochlea. The cochlea consists of two large ear canals- the upper vestibular canal and the lower vestibular canal. The two canals are separated by a cochlear duct. Semi-circular canals help in maintaining balance and posture of the body, and the cochlea helps in sending audio signals to the brain.

Access Answers to the NCERT Exemplar Class 11 Biology Solutions Chapter 21 (Short Questions)

Question:1

Answer:

Question:2

What is the difference between electrical transmission and chemical transmission?

Answer:

Question:3

The neural system and computers share certain common features. Comment in five lines. (Hint: CPU, input-output devices).

Answer:

1. The brain is the controlling and command center, just like the CPU (central processing unit) in a computer system.

2. The sense organs are like the input devices of a computer system.

3. Eyes and ears can be related to a web camera, scanner, and headphones.

4. Nerves are just like the cable wires in a computer.

5. The responses of the body are like the output material of the computer.

Question:4

If someone receives a blow on the back of the neck, what would be the effect on the person's CNS?

Answer:

A blow on the back of the neck can cause serious damage to the medulla oblongata and the spinal cord, which in turn can cause serious problems in the normal functioning of the respiratory, cardiovascular, and gastric systems. It can also cause paralysis.

Question:5

What is the function described to the Eustachian tube?

Answer:

The eustachian tube helps in equalizing pressures on both sides of the eardrum, and it is also involved in the reception and transmission of sound waves into the internal ear.

Question:6

Label the following parts in the given diagram using arrows.
(a) Aqueous chamber
(b) Cornea
(c) Lens
(d) Retina
(e) Vitreous chamber
(f) Blind spot

Answer:

NCERT Exemplar for Chapter 21 Neural Control and Coordination (Very Short Answer Type Questions)

Question:1

Rearrange the following in the correct order of involvement in electrical impulse movement: Synaptic knob, dendrites, cell body, Axon terminal, Axon.

Answer:

Dendrites, Cell body, Axon, Axon terminal, Synaptic knob.

Question:2

Comment on the role of the ear in maintaining the balance of the body and posture.

Answer:

The vestibular apparatus present in the internal ear consists of the semicircular canals and otolith. The semi-circular canals send signals to the brain in order to maintain balance and posture of the body.

Question:3

Which cells of the retina enable us to see coloured objects around us?

Answer:

Cone cells

Question:4

Arrange the following in the order of reception and transmission of sound waves from the eardrum: Cochlear nerve, external auditory canal, eardrum, stapes, incus, malleus, and cochlea.

Answer:

External auditory canal, Eardrum, Malleus, Incus, Stapes, Cochlea, Cochlear nerve.

Question:5

During resting potential, the axonal membrane is polarised, indicating the movement of +ve and -ve ions leading to polarization diagrammatically.

Answer:

Question:6

Name the structures involved in the protection of the brain.

Answer:

The skull and Cerebrospinal Fluid (CSF).

Question:7

Our reactions, like aggressive behavior, use of abusive words, restlessness, etc., are regulated by the brain; name the parts involved.

Answer:

The limbic system and hypothalamus is related to emotions.

Question:8

What do grey and white matter in the brain represent?

Answer:

The outer region of the cerebrum is composed of grey matter, which is also called the cerebral cortex. The grey matter represents the high concentration of cell bodies of the neuron. The inner region of the cerebrum is composed of white matter, which is also called the cerebral medulla. The white matter represents the high concentration of axons, which gives it a lighter appearance. Hence, the medulla is lighter in color and is called white matter.

Question:9

Where is the hunger center located in the human brain?

Answer:

The hunger center is located in the Hypothalamus in the human brain.

Question:10

Which sensory organ is involved in vertigo (sensation of oneself or objects spinning around)?

Answer:

Ears: semi-circular canals in the internal ears are involved in the sense of vertigo.

Question:11

While travelling at a higher altitude, a person complains of dizziness and a vomiting sensation. Which part of the inner ear is disturbed during the journey?

Answer:

Semi-circular canal

Question:12

Complete the statement by choosing the appropriate match among the following-

Answer:

(a)-(iii)

(b)-(iv)

(c)-(ii)

(d)-(i)

Also, check the NCERT Books and the NCERT Syllabus here

• NCERT Books Class 11 Biology

• NCERT Syllabus Class 11 Biology

• NCERT Books Class 11

• NCERT Syllabus Class 11

Approach to Solve Questions of NCERT Exemplar Class 11 Biology Solutions Chapter 21

Breaking down complex topics like neurons, synapses, and brain functions into simple parts makes it easier to understand and remember. Drawing diagrams, memorising sequences like nerve impulse transmission, and practising application-based questions help in answering both straightforward and tricky questions confidently.

• Read the Neural Control and Coordination Class 11 NCERT Exemplar carefully to understand neuron structure, synapse, and brain parts.

• Practice labelled diagrams of neurons, synapses, the brain, and sense organs.

• Memorise the steps of nerve impulse transmission and the reflex arc.

• Understand the differences between the sympathetic and parasympathetic nervous systems.

• Solve all NCERT exemplar solutions for class 11, focusing on reasoning and application.

Also, read the NCERT Solution subject-wise

• NCERT Solutions for Class 11 Maths

• NCERT Solutions for Class 11 Physics

• NCERT Solutions for Class 11 Chemistry

• NCERT Solutions for Class 11 Biology

Important Topic of Neural Control and Coordination Class 11 NCERT Exemplar

Below are the important topics from the chapter that students can go through to help them in the CBSE board exams, as well as other entrance exams:

• Structure and Function of a Neuron
• Nerve Impulse Transmission
• Synapse and Neurotransmitters
• Central and Peripheral Nervous System
• Reflex Action and Reflex Arc
• Sense Organs (Eye, Ear)
• Brain Structure and Functions
• Sympathetic and Parasympathetic Systems
• Neuromuscular Junction and Excitation–Contraction Coupling
• Ion Channel Types and Gating Mechanisms

NCERT Exemplar Class 11 Solutions

• NCERT Exemplar Class 11 Mathematics Solutions
• NCERT Exemplar Class 11 Chemistry Solutions
• NCERT Exemplar Class 11 Physics Solution

Advantages of NCERT Exemplar Class 11 Biology Chapter 21 Solutions

The Neural Control and Coordination chapter explains how the nervous system controls body functions through neurons, synapses, and neural impulses. Solving exemplar questions offers several advantages to students, some of which are mentioned below:

• NCERT Exemplar Class 11 Biology Chapter 21 Solutions gives a strong understanding of the structure of neurons, synaptic transmission, and conduction of nerve impulses.
• These questions improve the ability to answer diagram-based questions based on parts of the brain, reflex arcs, and neural pathways.
• Students will learn how to write answers in the correct format in the exam, improving scores in both school exams and competitive exams like NEET.
• Regular practice will increase the visual memory and improve retention of concepts, which boosts confidence in solving conceptual and application-based questions.
• Solving different types of questions improves problem-solving skills and reduces stress.

Important Questions of Neural Control and Coordination Class 11 NCERT Exemplar

Neural Control and Coordination is an important chapter for NEET as it explains how the nervous system functions, including nerve impulse transmission, reflexes, and sense organs. Practising previous years’ questions helps students focus on key concepts and understand the type of questions frequently asked in exams.

Question 1: Which of the following is not involved in the Knee reflex?

Option 1. Muscle spindle

Option 2. Motor neuron

Option 3. Brain

Option 4. Inter neurons

Answer:

An automatic response channel that does not directly engage the brain is known as the reflex arc. It consists of parts, including motor neurons, which send signals to muscles for contraction, interneurons, which let sensory and motor neurons in the spinal cord communicate, and muscle spindles, which sense changes in muscle length.

Hence, the correct answer is option (3) Brain

Question 2: Resting membrane potential is maintained by

Option 1. Hormones

Option 2. Neurotransmitters

Option 3. Ion pumps

Option 4. None of the above

Answer:

The sodium-potassium pump and leak channels are examples of ion pumps and channels that preserve a cell's resting membrane potential:
Potassium-sodium pump
For every ATP molecule, this pump transports two potassium ions into the cell and three sodium ions out of it. The potassium ion concentration gradient produced by this action adds to the resting membrane potential.

Hence, the correct answer is option (3): Ion pumps.

Question 3: The Potential difference across the resting membrane is negatively charged. This is due to the differential distribution of the following ions.

Option 1. Na⁺ and K⁺ ions

Option 2. CO₃^2-and Cl^- ions

Option 3. Ca²⁺ and Mg²⁺ ions

Option 4. Ca²⁺ and Cl^- ions

Answer:

The potential difference across the resting membrane is negative. This is due to the differential distribution of Na⁺ and K⁺ ions. The electrical charge differential across a cell membrane caused by the combined forces of ions and their permeability is known as the membrane potential. It is essential for both cellular communication and general bodily processes.

Hence, the correct answer is option (1) Na⁺ and K⁺ ions.

Question 4: Which part of the neuron is responsible for receiving impulses from other neurons?

Option 1. Axon

Option 2. Dendrites

Option 3. Cell body

Option 4. Axon terminal

Answer:

Dendrites are short, branched extensions of the neuron that receive nerve impulses from sensory receptors or other neurons and transmit them toward the cell body. They increase the surface area for receiving signals.

Hence, the correct answer is option (2) Dendrites.

Question 5: Which neurotransmitter is released at the neuromuscular junction?

Option 1. Dopamine

Option 2. Acetylcholine

Option 3. Noradrenaline

Option 4. Serotonin

Answer:

At the neuromuscular junction, motor neurons release acetylcholine, which binds to receptors on the muscle fiber membrane and initiates muscle contraction.

Hence, the correct answer is option (2) Acetylcholine.

Must Read NCERT Notes subject-wise

• NCERT Notes for Class 11 Maths

• NCERT Notes for Class 11 Physics

• NCERT Notes for Class 11 Chemistry

• NCERT Notes for Class 11 Biology

NCERT Exemplar Class 11 Biology Solutions Chapter Wise

The NCERT exemplar chapter-wise solutions for class 11 biology are given below-