Question

Which of the following is/are incorrect?
I) Reflex arc is the pathway that involves the transmission of impulse from CNS to effector organ only
II) Relay neuron connects the sensory and motor neuron.
III) The nerve that carries the impulse towards the CNS is an afferent nerve.
IV) Part of the central nervous system involved in reflex action can be spinal cord, ganglion or brain.
V) Withdrawal of hand or foot on being pricked is not an example of reflex action.

• A. I and V only
• B. II, III and IV only
• C. I, IV and V only
• D. All are correct

Answer 1

The correct option is A I and V only

Reflex action is the nerve mediated, spontaneous, automatic involuntary response to a stimulus acting on a specific receptor without consulting the will of the animal.
The reflex arc is the pathway that involves the transmission of impulse from the sensory organ to the effector organ via the CNS. The impulse from the sensory organ to the CNS is carried by afferent or sensory nerves. Whereas the impulse from the CNS to the effector organ is carried by efferent or motor neurons. The relay neuron present in the spinal cord of CNS connects the sensory and motor neuron. Part of the central nervous system (CNS) involved in the reflex action can be spinal cord, ganglion or brain. Withdrawal of hand or foot on being pricked is an example of reflex action.