This vital chapter of NCERT Solutions for Class 10 Science Chapter 6, Control and Coordination, helps us understand how living organisms respond to their environment and maintain harmony within their bodies. Whether it's pulling your hand away from a hot surface, feeling hungry at meal times, or a plant bending towards sunlight, these coordinated responses are controlled by the nervous and endocrine systems in animals and hormones in plants. This chapter is part of the comprehensive NCERT Solutions Class 10 Science series, which covers all chapters in detail.
The chapter equips students with essential skills to comprehend the structure and functioning of the nervous system, understand reflex actions, explore how hormones regulate body processes, and learn about coordination mechanisms in plants through tropic movements. Every solution has been designed keeping CBSE board exam patterns in mind, ensuring students develop both conceptual clarity and problem-solving confidence. By mastering this chapter, students build a strong foundation for human physiology, neuroscience, and endocrinology topics in higher classes.
NCERT Solutions for Class 10 Science Chapter 6 - All Exercise Questions
Q.
Which of the following is a plant hormone?
(a) Insulin
(b) Thyroxin
(c) Estrogen
(d) Cytokinin
Q.
The gap between two neurons is called a
(a) dendrite.
(b) synapse.
(c) axon.
(d) impulse.
Q.
The brain is responsible of
(a) thinking
(b) regulating the heart beat
(c) balancing of the body
(d)all of the above
Q.
What is the function of receptors in our body? Think of situations where receptors do not work properly? What problems are likely to arise?
Q.
Draw the structure of a neuron and explain its function.
Q.
How does phototropism occur in plants?
Q.
Which signals will get disrupted in case of a spinal cord injury?
Q.
How does chemical coordination occur in plants?
Q.
What is the need for a system of control and coordination in an organism?
Q.
How are involuntary actions and reflex actions different from each other?
Q.
Compare and contrast nervous and hormonal mechanisms for control and coordination in animals.
Q.
What is the difference between the manner in which movement takes place in a sensitive plant and the movement in our legs?
Class 10 Chapter 6 Science Questions & Answers – Control and Coordination
Q1. Which of the following is a plant hormone?
(a) Insulin
(b) Thyroxin
(c) Estrogen
(d) Cytokinin
Solution: d) Cytokinin
Explanation: Insulin, thyroxin and oestrogen are animal hormones.
Q2. The gap between two neurons is called a
(a) dendrite.
(b) synapse.
(c) axon.
(d) impulse.
Solution: b) Synapse
Explanation: Dendrite and axon are the parts of a neuron. Impulse is the electrical signal that travels through a neuron.
Q3. The brain is responsible of
(a) thinking
(b) regulating the heart beat
(c) balancing of the body
(d)all of the above
Soluton: d) all of the above
Explanation: Our brain is a part of the nervous system that plays an important role in the control and coordination of higher animals. Thinking, regulating heart beat and balancing of the body are some of the functions that are controlled by the brain.
Q4. What is the function of receptors in our body? Think of situations where receptors do not work properly? What problems are likely to arise?
Solution: The receptors are the sensory structures that on receiving environmental stimuli generate a nerve impulse. For example, our skin possesses many receptors that respond to the environmental stimuli such as increase or decrease in temperature, pain, etc. Taste receptors present on tongue help in identifying different tastes.
Functions of the receptors are:
- They sense the external stimuli.
- They also trigger impulse after perceiving stimuli.
When the receptors are damaged, the external stimuli, transferring signals to the brain are not felt. For example, when we drink hot coffee or tea, taste receptors on the tongue gets damaged. These damaged taste buds do not allow us to enjoy our food for a little while as they are not able to perceive the external stimuli i.e., taste of food.
Q5. Draw the structure of a neuron and explain its function.
Solution: Neuron is the structural and functional unit of nervous system. The parts of a neuron are cyton (cell body), axon, and dendrites.
Functions of the parts of a neuron:
Dendrite: It receives information from the axon of another neuron and conducts the message in the form of an impulse in the cyton (cell body).
Cyton (cell body): It consists of nucleus, mitochondria, and other cell organelles and concerned with the growth and maintenance of the neuron.
Axon: It helps in conducting messages in the form of impulse away from the cyton (cell body).
Q6. How does phototropism occur in plants?
Solution: Phototropism refers to the orientation of organisms in response to light. In plants, phototropism occurs due to the presence of a plant hormone called auxin. Auxin is synthesised at the shoot tips of the plants and help the plant cells to grow longer. In a case, when light is coming from one side of a plant, the plant hormone auxin diffuses towards the side of the plant shoot where no light is coming. The cells of the shoot which is away from the light start growing longer under the influence of plant hormone auxin and this causes bending of the plant towards light (phototropism).
Q7. Which signals will get disrupted in case of a spinal cord injury?
Solution: In case of a spinal cord injury, the signals coming from the nerves and the receptors and the signals reaching the effector organ will be disrupted.
Q8. How does chemical coordination occur in plants?
Solution: Plants do not possess a nervous system. Plants respond to the external and internal stimuli by showing different types of movements. In plants, growth, development and response to the stimuli is controlled and coordinated by certain chemical substances produced in their cells called hormones. A plant hormone is an organic compound which is synthesised at plant parts away from where they act and when required diffuses to the area of action. The five major types of plant hormones are auxins, gibberellins, cytokinins, abscisic acid and ethylene. These plant hormones either act as growth promoters or growth inhibitors. Auxins, gibberellins, cytokinins are growth promoters and abscisic acid and ethylene act as growth inhibitor.
Q9. What is the need for a system of control and coordination in an organism?
Solution: An organism comprises millions of cells, tissues, organs and organ systems. In an organism, all the organ systems work in coordination with each other and are responsible for the sustenance and survival of an organism in its environment. The more complex is the organism, the more coordination is required. It is very much necessary that various organ systems of an organism should work together in controlled and coordinated manner so that different body parts can function as a single unit and respond appropriately to the stimuli. In the absence of this system of control and coordination, our body will not be able to function properly. In animals, the control and coordination are provided by the nervous system and endocrine system whereas in plants nervous system is absent.
Q10. How are involuntary actions and reflex actions different from each other?
Solution: Involuntary actions cannot be consciously controlled. For example, we cannot consciously control the contraction and relaxation of our heart muscles. Involuntary actions are directly under the control of the brain. On the other hand, the reflex actions such as removal of hand just after getting pricked by a thorn shows sudden response and do not involve any thinking process. This clearly shows that the reflex actions are not under the control of brain as the involuntary actions are.
Q11. Compare and contrast nervous and hormonal mechanisms for control and coordination in animals.
Solution:
| Character |
Nervous Control and Coordination |
Hormonal Control and Coordination |
| Form of Information |
Nerve impulse |
Chemical messenger |
| Mode of transmission of information |
Through axons and dendrites |
Through blood |
| Flow of information |
Rapid |
Slow |
| Response |
Quick |
Slow |
| Duration of effect |
Short-lived |
Prolonged effects |
Q12. What is the difference between the manner in which movement takes place in a sensitive plant and the movement in our legs?
Solution: The movement that takes place in a sensitive plant such as Mimosa pudica is an example of the response to touch stimulus. In response to the stimulus of touch and for this movement to occur, the plant cells change their shape by changing the amount of water in them. Movement in our legs is a voluntary action. In a voluntary action, the signals are passed to the brain and hence are consciously controlled. In animal muscle cells, when a nerve impulse reaches the muscle cells, the muscle cells move by changing their shape. Muscle cells possess special proteins that on receiving the nerve impulse change their shape and arrangement which further cause the movement of the organ.
More Resources of NCERT Solutions for Class 10 Science
NCERT Solutions for Class 10 Science Chapter 6 – FAQs
Q1. What is the difference between nervous and hormonal control in animals?
Nervous control involves the transmission of electrical impulses through neurons for rapid, short-term responses to stimuli. The nervous system uses electrochemical signals that travel quickly along nerve cells, producing immediate but temporary effects like withdrawing your hand from a hot surface. Messages are precise and directed to specific organs. Hormonal control involves chemical messengers (hormones) secreted by endocrine glands that travel through the bloodstream to target organs. Hormonal responses are slower but longer-lasting, regulating processes like growth, metabolism, and reproduction. For example, adrenaline hormone prepares the body for emergency situations by increasing heart rate and blood pressure. While nerve impulses act in milliseconds, hormones may take seconds to hours to show effects, but their impact persists much longer.
Q2. What are reflex actions and how do they differ from voluntary actions?
Reflex actions are automatic, involuntary responses to stimuli that occur without conscious thought, controlled by the spinal cord through reflex arcs. Examples include blinking when something approaches your eye, pulling your hand away from a hot object, or knee-jerk response. The pathway involves: receptor → sensory neuron → spinal cord → motor neuron → effector (muscle), bypassing the brain for speed. Voluntary actions are conscious, deliberate responses controlled by the brain, such as picking up a pen, walking, or speaking. These require thinking and decision-making. Reflex actions are faster because the response pathway is shorter and doesn't involve processing in the brain, making them crucial for protecting the body from harm. The reflex arc allows the body to respond in fractions of a second, much faster than voluntary actions.
Q3. What are plant hormones and how do they control plant growth and movement?
Plant hormones (phytohormones) are chemical substances produced in small amounts that regulate various growth and developmental processes in plants. Auxins promote cell elongation, root formation, and apical dominance; they are responsible for phototropism (bending toward light) and geotropism (response to gravity). Gibberellins stimulate stem elongation, seed germination, and flowering. Cytokinins promote cell division and delay aging in leaves. Abscisic acid inhibits growth, causes stomatal closure during water stress, and induces seed dormancy. Ethylene promotes fruit ripening and leaf fall. Plant movements include tropic movements (directional growth responses like phototropism and geotropism caused by unequal distribution of auxins) and nastic movements (non-directional responses like the folding of touch-me-not leaves or opening and closing of flowers, caused by changes in water pressure in cells). Unlike animals, plants cannot move from place to place, so these hormones coordinate growth responses to environmental stimuli.RetryClaude can make mistakes. Please double-check responses. Sonnet 4.5