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Updated on 30 Jun 2026, 13:54 IST
Control and Coordination Class 10 Notes help students understand how living organisms respond to changes in their surroundings. This CBSE Class 10 Science Chapter 6 explains the nervous system, reflex action, human brain, plant hormones, tropic movements, endocrine glands, animal hormones, and feedback mechanism in a simple exam-focused way.
In animals, control and coordination are carried out mainly by the nervous system and the endocrine system. The nervous system gives fast responses through nerve impulses, while the endocrine system gives slower but longer-lasting responses through hormones. Plants do not have nerves or muscles, so they coordinate their activities through plant hormones and growth movements.
These notes are useful for NCERT revision, school exams, pre-board preparation, CBSE board exams, MCQs, assertion-reason questions, case-based questions, diagram-based questions, and quick last-minute revision.
Control and coordination is the process by which organisms detect changes in their environment and respond in a proper way. In animals, this is done through the nervous system and endocrine system, while in plants it is done through plant hormones and movement responses.
This chapter is important for CBSE Class 10 Science Notes because it includes definitions, comparison tables, labelled diagrams, reasoning questions, MCQs, assertion-reason questions, and application-based questions.
| Topic | What You Will Learn |
| Control and Coordination | How organisms respond to stimuli |
| Nervous System | Nerve impulse, neuron, brain, spinal cord and nerves |
| Reflex Action | Fast automatic response controlled mainly by spinal cord |
| Human Brain | Forebrain, midbrain and hindbrain functions |
| Plant Coordination | Hormonal control in plants |
| Plant Hormones | Auxin, gibberellin, cytokinin, abscisic acid and ethylene |
| Tropic Movements | Directional growth movements in plants |
| Nastic Movements | Non-directional movements in plants |
| Endocrine System | Hormones and ductless glands |
| Feedback Mechanism | Regulation of hormone secretion |
Students can download the Control and Coordination Class 10 Notes PDF for offline revision. The PDF includes definitions, labelled diagrams, comparison tables, reflex arc, neuron structure, human brain, plant hormones, endocrine glands, important questions, MCQs, and quick revision points.
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Control and coordination is the process by which living organisms detect stimuli and produce suitable responses. A stimulus may be light, heat, touch, sound, smell, gravity, water, chemicals or any change inside or outside the body.
For example, when a person touches a hot object, the hand is pulled away immediately. When a plant shoot receives light from one side, it bends toward the light. These responses are not random. They happen because organisms have systems to control and coordinate their activities.
| Term | Meaning | Example |
| Stimulus | A change that produces a response | Heat, light, touch, sound |
| Response | Reaction to a stimulus | Pulling hand away from heat |
| Receptor | Structure that detects stimulus | Skin receptors, eye receptors |
| Effector | Organ that produces response | Muscle or gland |
| Coordination | Working together of body parts | Brain, nerves and muscles acting together |
Control and coordination is important because different body parts must work together to produce a correct response. Without coordination, organs would work independently and the body would not be able to respond properly to danger, food, light, temperature or internal changes.
Movement and locomotion are not the same. Movement means a change in position of the whole body or a body part. Locomotion means movement of the entire organism from one place to another.
| Basis | Movement | Locomotion |
| Meaning | Change in position of body or body part | Movement of whole organism from one place to another |
| Seen in | Animals and plants | Mostly animals |
| Example | Plant shoot bending toward light | Dog running, bird flying |
| Key point | All movements are not locomotion | All locomotion involves movement |
The nervous system is a fast control and coordination system in animals. It receives information from receptors, processes it, and sends instructions to muscles or glands through electrical signals called nerve impulses.
The nervous system helps in fast responses such as blinking, pulling the hand away from heat, walking, writing, balancing the body and reacting to sudden changes.
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Animals have two main coordination systems: the nervous system and the endocrine system. The nervous system works quickly through nerve impulses, while the endocrine system works more slowly through hormones released into the blood.
| Feature | Nervous System | Endocrine System |
| Type of signal | Electrical impulses | Chemical messengers called hormones |
| Speed | Very fast | Slower |
| Duration of effect | Short-lasting | Long-lasting |
| Medium of transport | Neurons | Bloodstream |
| Target area | Usually specific and localised | May affect many organs |
| Example | Reflex action | Growth, puberty, blood sugar control |
| Main organs | Brain, spinal cord, nerves | Endocrine glands |
In short: Nervous control is fast and short-lived, while hormonal control is slower but longer-lasting.
A neuron is the structural and functional unit of the nervous system. It is a specialised cell that receives and transmits nerve impulses. A neuron mainly has three parts: dendrites, cell body and axon.
| Part of Neuron | Function |
| Dendrites | Receive impulses from receptors or other neurons |
| Cell body | Contains nucleus and controls cell activities |
| Axon | Carries impulses away from the cell body |
| Nerve ending | Passes impulse to another neuron, muscle or gland |
| Synapse | Small gap between two neurons |
Dendrite → Cell body → Axon → Nerve ending → Synapse → Next neuron / muscle / gland
Dendrites receive signals in. Axon carries signals away.
A nerve impulse begins when a receptor detects a stimulus. The receptor generates an electrical impulse. This impulse travels through the dendrite, reaches the cell body and then passes along the axon.
At the end of the axon, the impulse reaches a small gap called the synapse. The electrical signal causes the release of chemicals, which cross the synapse and start a new impulse in the next neuron.
Stimulus → Receptor → Sensory neuron → Central nervous system → Motor neuron → Effector → Response
A synapse is the small gap between the ending of one neuron and the dendrite of another neuron. It allows the nerve impulse to pass from one neuron to the next through chemical messengers.
A reflex action is a quick, automatic and involuntary response to a stimulus. It is controlled mainly by the spinal cord and helps protect the body from harm. The pathway followed by nerve impulses during a reflex action is called the reflex arc.
For example, when a person touches a hot object, the hand is withdrawn immediately without conscious thinking. This happens because the spinal cord sends a quick message to the muscles before the brain fully processes the pain.
Reflex action is an automatic response that does not require conscious control. It is very fast and protects the body from injury.
The reflex arc is the nerve pathway involved in a reflex action. It includes receptor, sensory neuron, spinal cord, motor neuron and effector.
Receptor → Sensory neuron → Spinal cord → Motor neuron → Effector
| Step | What Happens |
| 1 | Heat receptors in the skin detect heat |
| 2 | Sensory neuron carries impulse to spinal cord |
| 3 | Spinal cord processes the message quickly |
| 4 | Motor neuron carries impulse to arm muscles |
| 5 | Arm muscles contract and hand is pulled away |
Hot object
↓
Receptor in skin
↓
Sensory neuron
↓
Spinal cord
↓
Motor neuron
↓
Muscle
↓
Hand withdrawn
Reflex action is controlled mainly by the spinal cord because the response must be very fast. If the signal had to travel to the brain first and then return to the muscles, the response would take more time. The brain receives the information slightly later, which is why we become aware of pain after the hand has already moved away.
The human brain is the main coordinating centre of the body. It controls thinking, memory, emotions, voluntary actions, balance, posture and many involuntary actions such as heartbeat and breathing.
The brain is protected by the skull. It works with the spinal cord to form the central nervous system.
The human brain has three main parts:
| Brain Part | Main Structures | Functions |
| Forebrain | Cerebrum, hypothalamus | Thinking, memory, intelligence, voluntary actions, hunger and thirst |
| Midbrain | — | Reflex movements of head, neck and eyes |
| Hindbrain | Cerebellum, pons, medulla | Balance, posture, coordination, breathing, heartbeat and blood pressure |
The forebrain is the largest and most developed part of the brain. It includes the cerebrum and hypothalamus.
The cerebrum is the largest part of the brain. It controls intelligence, memory, learning, emotions, thinking and voluntary actions.
Writing an answer, solving a question, reading a sentence and deciding to raise your hand are controlled by the cerebrum.
The cerebellum is a part of the hindbrain. It controls posture, balance and coordination of voluntary movements.
Walking in a straight line, cycling, dancing and writing neatly require proper coordination by the cerebellum.
The medulla controls many involuntary actions that are essential for survival.
The nervous system is divided into the central nervous system and peripheral nervous system.
| Part | Includes | Function |
| Central Nervous System | Brain and spinal cord | Processes information and controls responses |
| Peripheral Nervous System | Nerves from brain and spinal cord | Connects CNS with the rest of the body |
Actions in the body may be voluntary, involuntary or reflex. These actions differ based on whether they are under conscious control and how fast they occur.
| Type of Action | Meaning | Controlled By | Example |
| Voluntary action | Action done under conscious control | Brain | Writing, walking, speaking |
| Involuntary action | Action not under conscious control | Brain stem / autonomic control | Heartbeat, breathing, digestion |
| Reflex action | Sudden automatic response to stimulus | Spinal cord | Pulling hand away from heat |
Muscles move when they receive nerve impulses from the nervous system. The impulse causes changes in muscle cells, making them contract. When muscles contract and relax, movement occurs.
Muscles usually work in pairs. One muscle contracts while the other relaxes. This allows body parts to move in different directions.
When the arm bends at the elbow, one muscle contracts while the opposite muscle relaxes. When the arm straightens, the action is reversed.
Plants do not have a nervous system, muscles or sense organs like animals. Still, they respond to light, gravity, water, touch and chemicals. They coordinate their activities with the help of plant hormones and special types of movements.
Plant responses are usually slower than animal responses because many plant movements depend on growth.
| Basis | Animals | Plants |
| Coordination system | Nervous system and endocrine system | Plant hormones |
| Speed of response | Usually fast | Usually slow |
| Movement | Muscles and nerves | Growth or turgor changes |
| Response type | Reflex action, voluntary action, hormonal action | Tropic and nastic movements |
| Example | Hand withdrawn from heat | Shoot bends toward light |
Plant hormones, also called phytohormones, are chemical substances that control growth, development and movement in plants. They are produced in very small amounts and act on different parts of the plant.
Plant hormones help in cell elongation, cell division, stem growth, fruit ripening, dormancy, stomatal closure and bending responses.
| Plant Hormone | Main Function |
| Auxin | Promotes cell elongation and helps in phototropism |
| Gibberellin | Promotes stem growth |
| Cytokinin | Promotes cell division |
| Abscisic acid | Inhibits growth and helps close stomata during stress |
| Ethylene | Helps in fruit ripening |
Auxin is produced at the shoot tip. When light comes from one side, auxin moves toward the shaded side of the shoot. Cells on the shaded side elongate faster than cells on the lighted side. As a result, the shoot bends toward light.
This is why plant shoots show positive phototropism.
Tropic movements are directional growth movements in plants in response to a stimulus. The direction of movement depends on the direction of the stimulus. If the plant part grows toward the stimulus, it is called positive tropism. If it grows away from the stimulus, it is called negative tropism.
| Movement | Stimulus | Example |
| Phototropism | Light | Shoot bends toward light |
| Geotropism / Gravitropism | Gravity | Roots grow downward |
| Hydrotropism | Water | Roots grow toward water |
| Chemotropism | Chemicals | Pollen tube grows toward ovule |
| Thigmotropism | Touch | Tendrils coil around support |
| Type | Meaning | Example |
| Positive tropism | Growth toward the stimulus | Shoot growing toward light |
| Negative tropism | Growth away from the stimulus | Root growing away from light |
Nastic movements are non-directional movements in plants. In these movements, the direction of response does not depend on the direction of the stimulus. These movements are usually faster than tropic movements and are often caused by changes in water pressure inside cells.
The leaves of the touch-me-not plant fold when touched. This response does not depend on the direction of touch, so it is a nastic movement.
| Basis | Tropic Movements | Nastic Movements |
| Direction | Directional | Non-directional |
| Depends on stimulus direction | Yes | No |
| Speed | Usually slow | Usually fast |
| Growth involved | Usually growth-dependent | Usually not growth-dependent |
| Reversibility | Usually irreversible | Usually reversible |
| Example | Shoot bends toward light | Mimosa leaves fold on touch |
The endocrine system is made up of ductless glands that secrete hormones directly into the blood. Hormones are chemical messengers that regulate growth, metabolism, blood sugar, emergency responses and secondary sexual characters.
Hormones act only on specific target organs even though they travel through the blood.
| Endocrine Gland | Hormone | Main Function |
| Pituitary gland | Growth hormone | Controls body growth |
| Thyroid gland | Thyroxine | Controls metabolism |
| Adrenal gland | Adrenaline | Prepares body for emergency |
| Pancreas | Insulin | Controls blood sugar level |
| Testes | Testosterone | Controls male secondary sexual characters |
| Ovaries | Oestrogen | Controls female secondary sexual characters |
The pituitary gland is often called the master gland because it controls the activity of many other endocrine glands. It secretes growth hormone, which regulates growth of the body.
| Condition | Result |
| Deficiency in childhood | Dwarfism |
| Excess in childhood | Excessive growth |
The thyroid gland secretes thyroxine. Thyroxine controls the rate of metabolism in the body. Iodine is necessary for the production of thyroxine.
Iodised salt is recommended because iodine is needed to produce thyroxine. Lack of iodine can cause deficiency of thyroxine, which may lead to goitre. Goitre causes swelling in the neck region.
Adrenaline is secreted by the adrenal glands during stress, fear, anger or emergency. It prepares the body for quick action.
Insulin is secreted by the pancreas. It helps control blood sugar level by allowing body cells to take up glucose from the blood.
If the pancreas does not produce enough insulin, blood sugar level rises. This condition is known as diabetes.
The feedback mechanism is the process by which the body regulates hormone levels. It helps maintain the correct amount of hormone in the blood. Most hormonal feedback in the body works through negative feedback.
In negative feedback, if hormone level becomes too high, secretion is reduced. If hormone level becomes too low, secretion is increased.
When thyroxine level in the blood falls, the pituitary gland releases more thyroid stimulating hormone. This stimulates the thyroid gland to produce more thyroxine. When thyroxine level becomes normal, the pituitary reduces thyroid stimulating hormone secretion.
Low thyroxine → More TSH from pituitary → Thyroid secretes more thyroxine → Thyroxine level becomes normal → TSH secretion reduces
When blood sugar level rises, the pancreas secretes insulin. Insulin helps body cells absorb glucose from the blood. As blood sugar level becomes normal, insulin secretion decreases.
High blood sugar → Pancreas secretes insulin → Cells absorb glucose → Blood sugar becomes normal → Insulin secretion decreases
Students should practise neat and labelled diagrams because this chapter commonly includes diagram-based questions.
| Diagram | Important Labels |
| Structure of neuron | Dendrite, cell body, nucleus, axon, nerve ending |
| Reflex arc | Receptor, sensory neuron, spinal cord, motor neuron, effector |
| Human brain | Cerebrum, cerebellum, medulla, pons |
| Phototropism in shoot | Light source, shoot tip, auxin movement, bending |
| Endocrine glands | Pituitary, thyroid, adrenal gland, pancreas, testes, ovaries |
| Common Mistake | Correct Concept |
| Thinking reflex action is controlled by the brain | Reflex action is mainly controlled by the spinal cord |
| Confusing stimulus and response | Stimulus is the change; response is the reaction |
| Thinking plants have nerves | Plants do not have a nervous system |
| Confusing tropic and nastic movement | Tropic is directional; nastic is non-directional |
| Writing all plant movements are fast | Many plant movements are slow because they depend on growth |
| Writing all hormones act fast | Hormonal responses are usually slower but longer-lasting |
| Confusing insulin and adrenaline | Insulin controls blood sugar; adrenaline prepares body for emergency |
| Forgetting iodine’s role | Iodine is needed to produce thyroxine |
| Writing auxin bends shoot directly | Auxin causes unequal growth, which bends the shoot |
| Confusing voluntary and involuntary actions | Voluntary actions are conscious; involuntary actions are automatic |
A. Brain
B. Neuron
C. Spinal cord
D. Hormone
Answer: B. Neuron
A. Cerebrum
B. Spinal cord
C. Thyroid gland
D. Pancreas
Answer: B. Spinal cord
A. Insulin
B. Thyroxine
C. Adrenaline
D. Growth hormone
Answer: C. Adrenaline
A. Auxin
B. Abscisic acid
C. Ethylene
D. Insulin
Answer: A. Auxin
A. Cerebrum
B. Cerebellum
C. Medulla
D. Hypothalamus
Answer: B. Cerebellum
A. Thyroid
B. Pancreas
C. Adrenal
D. Pituitary
Answer: B. Pancreas
A. Geotropism
B. Phototropism
C. Hydrotropism
D. Chemotropism
Answer: B. Phototropism
A. Phototropism
B. Geotropism
C. Nastic movement
D. Chemotropism
Answer: C. Nastic movement
Assertion: Reflex actions are faster than voluntary actions.
Reason: Reflex actions are controlled mainly by the spinal cord and do not require conscious thinking.
Answer: Both Assertion and Reason are true, and Reason is the correct explanation of Assertion.
Assertion: Plants bend toward light due to auxin.
Reason: Auxin causes faster cell elongation on the shaded side of the shoot.
Answer: Both Assertion and Reason are true, and Reason is the correct explanation of Assertion.
Assertion: Hormonal responses are usually slower than nervous responses.
Reason: Hormones are transported through blood to reach target organs.
Answer: Both Assertion and Reason are true, and Reason is the correct explanation of Assertion.
Assertion: Iodised salt is recommended in diet.
Reason: Iodine is required for the synthesis of thyroxine.
Answer: Both Assertion and Reason are true, and Reason is the correct explanation of Assertion.
A student touches a hot metal pan accidentally and immediately pulls the hand away. After a moment, the student feels pain and realises that the pan was hot. The teacher explains that this response happened through a reflex arc.
Control and Coordination is an important Class 10 Science chapter because it explains how animals and plants respond to their surroundings. In animals, coordination is done through the nervous system and endocrine system. In plants, coordination is done through plant hormones and movements such as phototropism, geotropism and nastic movement.
For scoring well in this chapter, students should focus on neuron structure, reflex arc, functions of the brain, plant hormones, tropic and nastic movements, endocrine glands, animal hormones and feedback mechanism. Practise labelled diagrams, comparison tables, MCQs, assertion-reason questions and short-answer questions for better exam preparation.
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In the current CBSE Class 10 Science syllabus, Control and Coordination is Chapter 6. In earlier syllabus editions and some older study material, it was numbered Chapter 7. The chapter content itself has not changed — only the numbering.
Control and coordination refer to the way living organisms manage their body activities and respond appropriately to changes in their surroundings. In animals, this is achieved using the nervous system and the endocrine system. In plants, it is achieved through hormones and specific types of movement, since plants lack a nervous system entirely.
A reflex action is a spontaneous, automatic, and involuntary response to a stimulus, controlled by the spinal cord rather than the brain. It allows the body to react to potentially harmful stimuli — such as a hot object — faster than would be possible if the signal had to travel all the way to the brain and back.
Nervous control acts through electrical impulses carried by neurons, producing very fast but short-lived and highly localised responses. Hormonal control acts through chemical messengers carried in the bloodstream, producing slower but longer-lasting and more widespread responses. The two systems often work together to produce a complete and balanced response.
Phototropism is the directional growth movement of a plant part in response to light. Shoots typically grow toward light (positive phototropism), while roots typically grow away from it (negative phototropism). This movement is controlled by the redistribution of the hormone auxin within the plant.
The feedback mechanism is the process by which the body regulates hormone levels to maintain a stable internal balance. In a typical negative feedback loop, when a hormone's level falls below normal, its secretion increases; when the level rises above normal, secretion decreases. The regulation of thyroxine through TSH from the pituitary gland is a standard example used to explain this concept.
Iodised salt provides a steady source of dietary iodine, which is essential for the thyroid gland to produce thyroxine. Without adequate iodine, thyroxine production falls and the thyroid gland enlarges to compensate, resulting in a condition called goitre.
The human brain contains approximately 86 billion neurons, reflecting the immense complexity of the nervous system and its capacity for processing information.
Tropic movements are directional and growth-dependent, meaning the direction of the plant's response depends on the direction of the stimulus, and the movement is generally slow and irreversible. Nastic movements are non-directional and turgor-dependent, meaning the response does not depend on the direction of the stimulus, and the movement is generally fast and reversible.
The cerebellum, located in the hindbrain, coordinates voluntary movements and is primarily responsible for maintaining the body's posture and balance. Activities requiring precise physical coordination, such as cycling or writing, rely heavily on proper cerebellar function.