Looking for accurate SEBA Class 10 Science Chapter 7 (Control and Coordination) solutions for the 2026–27 academic year? Access step-by-step textual exercise answers, in-text question solutions, and clear biological diagrams designed to help you score 100% in your HSLC board exams.
Blue question
Q1. What is the difference between a reflex action and walking?
Answer: A reflex action is an involuntary, rapid, and automatic response to a stimulus that occurs without conscious thinking. Walking is a voluntary action controlled by the brain that requires conscious thought and is done according to our will.
Q2. What happens at the synapse between two neurons?
Answer: At the synapse, electrical impulses trigger the release of chemical signals from the end of one neuron. These chemicals cross the gap and bind to receptors on the next neuron to generate a new electrical impulse.
Q3. Which part of the brain maintains the posture and equilibrium of the body?
Answer: The cerebellum, located in the hindbrain, maintains the posture, balance, and equilibrium of the body.
Q4. How do we detect the smell of an incense stick (agarbatti)?
Answer: Olfactory receptors in the nose detect the chemical particles of the smell and send electrical signals to the forebrain, which interprets and recognizes the smell.
Q5. What is the role of the brain in a reflex action?
Answer: Reflex actions are directly controlled by the spinal cord for a fast response, so the brain has no direct role in triggering them. However, the brain receives the sensory information and registers the event after the reflex action has taken place.
SEBA Class 10 Science Chapter 7 Solutions
Q6. What are plant hormones?
Answer: Plant hormones (phytohormones) are chemical substances naturally produced in plants that regulate their growth, development, and responses to the environment. Examples include auxins, gibberellins, and cytokinins.
Q7. How is the movement of leaves of a sensitive plant different from the movement of a shoot towards light?
Answer: The folding of leaves in a sensitive plant is a nastic movement that is fast, non-directional, and independent of growth. The bending of a shoot towards light is a tropic movement (phototropism) that is slow, directional, and dependent on plant growth.
Q8. Give an example of a plant hormone that promotes growth.
Answer: Auxin is an example of a plant hormone that promotes cell elongation and growth.
Q9. How do auxins promote the growth of a tendril around a support?
Answer: When a tendril comes in contact with a support, auxins diffuse towards the side away from the support. This side grows faster than the side in contact, causing the tendril to bend and coil around the support.
Q10. How can you design a simple experiment to demonstrate hydrotropism in plants?
Answer: Place a porous clay pot filled with water inside a box containing dry soil and plant a young seedling nearby. After a few days, observe that the roots bend and grow towards the moist region around the water pot, demonstrating positive hydrotropism.
Class 10 Science Chapter 7 Question Answer SEBA 2026-27
Q11. How does chemical coordination take place in animals?
Answer: Chemical coordination in animals takes place through hormones, which are chemical messengers secreted directly into the bloodstream by endocrine glands to reach and regulate target tissues or organs.
Q12. Why is the use of iodized salt advisable?
Answer: The use of iodized salt is advisable because iodine is essential for the thyroid gland to produce thyroxine hormone, which regulates carbohydrate, protein, and fat metabolism, and prevents goiter.
Q13. How does our body respond when adrenaline is secreted into the blood?
Answer: When adrenaline is secreted into the blood during emergency or stressful situations, it increases the heart rate, elevates breathing rate, raises blood pressure, and diverts more blood to skeletal muscles to prepare the body for immediate action.
Q14. Why are some patients with diabetes treated by giving injections of insulin?
Answer: Some diabetic patients are treated with insulin injections because their pancreas produces insufficient insulin, which is needed to regulate and lower high blood glucose levels.
Control and Coordination Class 10 SEBA Textual Exercise Solutions
Excerise
Q1. Which of the following is a plant hormone?
A) Insulin
B) Thyroxin
C) Oestrogen
D) Cytokinin
Answer: D) Cytokinin
Explanation: Cytokinin is a plant hormone that promotes cell division, shoot initiation, and growth. Insulin, thyroxin, and oestrogen are animal hormones.
Q2. The gap between two neurons is called a:
A) Dendrite
B) Synapse
C) Axon
D) Impulse
Answer: B) Synapse
Explanation: A synapse is the microscopic functional junction between two adjacent neurons where chemical neurotransmitters transmit signals across the gap.
Q3. The brain is responsible for:
A) Thinking
B) Regulating the heartbeat
C) Balancing the body
D) All of the above
Answer: D) All of the above
Explanation: The brain performs complex cognitive functions like thinking (forebrain), regulates vital involuntary functions like heartbeat (medulla), and maintains posture and balance (cerebellum).
Q4. What is the function of receptors in our body? What problems are likely to arise if receptors do not work properly?
Answer: Receptors are specialized sensory structures that detect changes in the environment (stimuli) and convert them into electrical signals for the nervous system. If receptors fail to function properly, the body cannot sense stimuli like pain, heat, or sound, leading to delayed protective responses, impaired spatial awareness, and a higher risk of injury.
Q5. Describe the basic structure of a neuron and state its primary function.
Answer: A neuron consists of three main parts: dendrites that receive incoming signals, a cell body (cyton) that processes information, and a long axon that transmits electrical impulses to other cells. Its primary function is to conduct nerve impulses rapidly throughout the body to enable communication and coordination.
SEBA Class 10 Science Control and Coordination Notes
Q6. How does phototropism occur in plants?
Answer: Phototropism occurs when light shines on one side of a plant shoot, causing the growth hormone auxin to diffuse toward the shaded side. The higher concentration of auxin stimulates cells on the shaded side to elongate faster, causing the shoot to bend toward the light source.
Q7. Which signals will get disrupted in case of a spinal cord injury?
Answer: A spinal cord injury disrupts both sensory signals traveling from body organs up to the brain and motor signals traveling down from the brain to muscles. Involuntary reflex actions controlled by the affected spinal region will also be lost or impaired.
Q8. How does chemical coordination occur in plants?
Answer: Chemical coordination in plants occurs through plant hormones (phytohormones) like auxins, gibberellins, cytokinins, and abscisic acid. These chemical messengers diffuse through tissues to regulate target processes like cell division, stem elongation, leaf fall, and responses to environmental stimuli.
Q9. What is the need for a system of control and coordination in an organism?
Answer: A control and coordination system is necessary to integrate and synchronize the activities of various organs so that the body operates as a unified unit. It enables organisms to respond safely and effectively to internal and external environmental changes.
Q10. How are involuntary actions and reflex actions different from each other?
Answer: The main differences between involuntary actions and reflex actions are:
- Involuntary actions are continuous internal activities regulated primarily by the brain (such as heartbeat and digestion), whereas reflex actions are rapid, sudden responses to external stimuli regulated by the spinal cord (such as withdrawing a hand from a hot surface).
- Involuntary actions occur constantly without an immediate conscious trigger, whereas reflex actions are immediate emergency responses to specific external danger signals.
Q11. Compare and contrast nervous and hormonal mechanisms for control and coordination in animals.
Answer: The main differences between nervous and hormonal mechanisms are:
- The nervous system uses electrical impulses along nerve fibers, resulting in a very fast response, whereas the hormonal system uses chemical messengers carried through the blood, resulting in a slower response.
- Nervous responses are highly specific, short-lived, and localized, whereas hormonal responses are widespread, longer-lasting, and can affect multiple target organs simultaneously.
HSLC Science Chapter 7 Question Answer
Q12. What is the difference between the manner in which movement takes place in a sensitive plant and the movement in our legs?
Answer: The main differences in movement are:
- Movement in a sensitive plant occurs due to changes in the amount of water (turgor pressure) inside cells, causing them to swell or shrink, whereas movement in our legs occurs due to the contraction and relaxation of specialized muscle proteins.
- Plant movement is an involuntary reaction without nerve tissue or specialized proteins, whereas movement in human legs is a voluntary action controlled by nerve impulses sent from the brain and spinal cord.
🔬 Updated Solutions Notice: This page features complete, step-by-step SEBA Class 10 Science Chapter 7 (Control and Coordination) Textual Exercise Solutions updated for the 2026–27 academic session. All explanations, reflex arc diagrams, and plant hormone functions strictly follow the latest revised Assam Board (SEBA) textbook.
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