Extra 30 short-answer questions from the Chapter 6 Control and Coordination chapter of Class 10 CBSE Science, along with their answers.
Short Answer Questions
What is the difference between voluntary and involuntary actions?
Answer:
Voluntary actions: Controlled by the cerebrum; actions done consciously, e.g., walking, writing.
Involuntary actions: Controlled by the medulla oblongata and spinal cord; actions happen automatically, e.g., heartbeat, digestion.
What is a neuron? Draw a labelled diagram of a neuron.
Answer:
A neuron is the structural and functional unit of the nervous system.
It transmits electrical impulses between different parts of the body.
Parts: Dendrites, Cell body, Axon, Axon terminals. (Draw a neuron diagram)
What is a reflex action? Give an example.
Answer:
A reflex action is an automatic and rapid response to a stimulus without conscious control.
Example: Pulling your hand away after touching a hot object.
Differentiate between sensory and motor neurons.
Answer:
Sensory Neurons
: Carry impulses from sense organs to the brain/spinal cord.
Motor Neurons: Carry impulses from the brain/spinal cord to muscles or glands.
Explain the role of synapse in nerve impulse transmission.
Answer:
A synapse is a junction between two neurons where nerve impulses pass chemically.
The impulse triggers the release of neurotransmitters, which help the impulse move to the next neuron.
What are meninges? Mention their function.
Answer:
Meninges are protective membranes surrounding the brain and spinal cord.
They protect the CNS from mechanical injuries.
What are the functions of the spinal cord?
Answer:
It transmits signals between the brain and the body.
It controls reflex actions.
What is the function of the cerebrum?
Answer:
Controls voluntary actions, intelligence, reasoning, memory, and emotions.
What is the role of the cerebellum?
Answer:
Maintains balance and coordination of the body.
What is the function of the medulla oblongata?
Answer:
Controls involuntary actions like breathing, heartbeat, and digestion.
What is the endocrine system? How is it different from the nervous system?
Answer:
The endocrine system consists of glands that secrete hormones into the blood.
Difference:
Nervous system: Works through electrical signals; fast response.
Endocrine system: Works through hormones; slow but long-lasting response.
What is the function of the pituitary gland?
Answer:
Known as the master gland, it controls other glands and secretes growth hormone.
Which hormone controls metabolism? Name the gland that secretes it.
Answer:
Thyroxine hormone, secreted by the thyroid gland.
What causes goitre? How can it be prevented?
Answer:
Cause: Deficiency of iodine, leading to thyroid gland swelling.
Prevention: Consuming iodized salt.
Which hormone regulates blood sugar levels? Name the gland that secretes it.
Answer:
Insulin, secreted by the pancreas.
What is the role of adrenaline?
Answer:
Prepares the body for fight or flight response by increasing heart rate and breathing.
What are sex hormones? Name two important sex hormones.
Answer:
Hormones that regulate sexual development.
Testosterone (male) and Oestrogen (female).
What is the role of glucagon?
Answer:
Glucagon, secreted by the
pancreas
,
increases blood sugar levels
.
Which gland is called the "biological clock" of the body? Why?
Answer:
The
pineal gland
, because it
regulates sleep cycles
by secreting
melatonin
.
How do hormones help in growth and development?
Answer:
Growth hormone (GH) promotes body growth.
Thyroxine controls metabolism.
What is phototropism? Give an example.
Answer:
Growth of a plant towards light.
Example: Sunflower bending towards sunlight.
What is geotropism? Give an example.
Answer:
Response of a plant towards gravity.
Example: Roots grow downward (positive geotropism), stem grows upward (negative geotropism).
What is
thigmotropism
? Give an example.
Answer:
Response of a plant to touch.
Example: Climbing vines wrap around a support.
What is hydrotropism? Give an example.
Answer:
Growth of a plant
towards water
.
Example:
Roots growing towards a water source
.
Which plant hormone controls cell division?
Answer:
Cytokinin
.
Which plant hormone is responsible for fruit ripening?
Answer:
Ethylene
.
What is abscisic acid? What is its function?
Answer:
A plant hormone that
inhibits growth
and causes
leaf fall
.
Differentiate between tropic and nastic movements.
Answer:
Tropic movements: Directional growth movements in response to a stimulus (e.g., phototropism).
Nastic movements: Non-directional movements (e.g., Mimosa leaf closing when touched).
Why do some plants droop when touched?
Answer:
Due to the
loss of water
in specific cells, leading to
nastic movement
(seen in
Mimosa
pudica
).
What is chemotropism? Give an example.
Answer:
Growth in response to chemicals.
Example:
Pollen tube growing towards the ovule due to chemical signals
.
