Home · Schooling · CBSE · Class 10 · Science · Control and Coordination · In-text questions (page 105)
NCERT Class 10 Science Control and Coordination: In-text questions (page 105) Solutions
AI-written, checked on 23 Oct 2026
Solutions written by Shishya, checked — not the board's official answers
Step-by-step working for every question of In-text questions (page 105) in NCERT's Class 10 Science book, chapter “Control and Coordination”, written by Shishya. Each question is in our own short words; open the NCERT chapter for the exact wording and figures.
How these were checked: the solutions were drafted with AI and then read and corrected on 23 Oct 2026. Every numerical final answer is recomputed from the question's own numbers by a calculator check that runs before each release; proofs and explanations were read, not machine-checked. The NCERT textbook is the authority — if something here disagrees with it, follow the book.
Tap “why?” under a step to see the textbook rule it uses — from Shishya's fixed list of NCERT Class 9-10 rules, not written by AI for this page. A step without one has no rule from the list yet.
Stuck on a step?
Ask the AI tutor about this chapter — it gives hints before answers — or snap a photo of your own question to get worked steps. You will be talking to an AI, not a person. For ages 13 and up; the first answer of each is free.
In-text (page 105) Q1
How does a reflex action differ from walking?
- A reflex action is an involuntary, rapid response to a stimulus that does not involve conscious thought.
- The neural pathway for a reflex action is a short reflex arc involving only the spinal cord and peripheral nerves.
- Walking is a voluntary action that requires conscious control and planning by the brain.
- The neural pathway for walking involves the brain, spinal cord, and complex coordination of multiple muscle groups.
- Reflex actions are automatic and protective, while walking is a learned, coordinated movement.
Answer: Reflex action is involuntary and fast (spinal cord only), while walking is voluntary and controlled by the brain.
In-text (page 105) Q2
What happens at the synapse between two neurons?
- When an electrical signal reaches the end of the axon of the first neuron, it triggers the release of chemical messengers called neurotransmitters.
- These neurotransmitters are stored in tiny vesicles within the synaptic knob and are released into the synaptic gap.
- The chemicals diffuse across the gap and bind to specific receptors on the dendrite of the next neuron.
- This binding generates a new electrical impulse in the second neuron, allowing the signal to continue.
- The neurotransmitters are then broken down or reabsorbed to stop the signal and prepare for the next transmission.
Answer: Chemical signals (neurotransmitters) are released from the axon terminal of the first neuron, cross the synapse, and trigger an electrical impulse in the dendrite of the next neuron.
In-text (page 105) Q3
Which part of the brain maintains posture and balance of the body?
- The cerebellum is the part of the brain responsible for maintaining posture and balance.
- It coordinates voluntary movements and ensures smooth muscle activity.
- Damage to the cerebellum leads to loss of balance and coordination.
Answer: Cerebellum
In-text (page 105) Q4
How do we detect the smell of an agarbatti (incense stick)?
- The burning agarbatti releases tiny particles of fragrance into the air.
- These particles mix with the air and move towards our nose through the process of diffusion.
- The olfactory receptors in the nasal cavity detect these fragrance particles.
- The receptors generate electrical signals which are transmitted via olfactory nerves to the brain.
- The brain processes these signals and identifies the specific smell of the agarbatti.
Answer: We detect the smell of an agarbatti because fragrance particles diffuse in the air, are detected by olfactory receptors in the nose, and the resulting signals are interpreted by the brain.
In-text (page 105) Q5
What is the role of the brain in a reflex action?
- A reflex action is an involuntary and rapid response to a stimulus that does not require conscious thought.
- The sensory neuron carries the impulse from the receptor to the spinal cord, which acts as the reflex arc center.
- The spinal cord processes the information and sends the motor impulse to the effector organ to produce the response.
- The brain is not involved in the immediate execution of the reflex action because the pathway bypasses it for speed.
- However, the brain receives a copy of the nerve impulse after the reflex has occurred to register the event.
- This allows the brain to be aware of the stimulus and the response, even though it did not initiate the action.
Answer: The brain is not involved in the immediate reflex action but receives information about it afterwards to register the event.
Other exercises in this chapter
- In-text questions (page 108) — 5 questions
- In-text questions (page 111) — 4 questions
- End-of-chapter exercises — 12 questions
← Control and Coordination: notes, practice and all exercises
Saves these solutions in this browser on this phone. No sign-in; nothing about you is saved or sent. A saved copy is not updated until you save it again. Parts that load from the server when you use them (the AI tutor, adaptive practice, sign-in) still need a connection.