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
.
