Question

Which of the following statements are true?
(i) Sudden reaction in response to the stimulus is called reflex action.
(ii) Sensory neurons carry signals from the spinal cord to muscles.
(iii) Motor neurons carry signals from receptors to spinal cord.
(iv) Reflex arc is the process in which the nerve impulse is carried and the response is generated.

• A. (i) and (ii)
• B. (i) and (iii)
• C. (i) and (iv)
• D. (i),(ii) and (iii)

Answer 1

The correct option is C (i) and (iv)

$\bullet$ With respect to the statements given, (ii) and (iii) are incorrect.
$\bullet$ Sensory neurons are responsible for carrying signals from the receptors to the spinal cord and brain whereas motor neurons are responsible for carrying signals from the spinal cord to muscles.
$\bullet$ Reflex actions are always immediate and happen without much of the thinking process. Moving your hand immediately on touching a hot object is an example of reflex action.
$\bullet$ Reflex arc can be explained as a process in which nerve impulse is carried and the response is generated by effector organs. They show the response by either contracting the muscle or by secreting a product.