Question

Which of the following statements are true?

(i) Sudden action in response to something in the environment is called reflex action

(ii) Sensory neurons carry signals from the spinal cord to muscles

(iii) Motor neurons carry signals from receptors to the spinal cord

(iv) The path through which signals are transmitted from a receptor to a muscle or a gland is called the reflex arc.

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

Answer 1

The correct option is C

(i) and (iv)

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

The explanation of the correct options:

1. Reflex action is a sudden and automatic response to the external environment.
2. Reflex action helps to adapt fast to an adverse circumstance.
3. A reflex arc is a neural pathway during a reflex action. Signal transmission takes place from a receptor to a muscle or a gland.

The explanation of the incorrect options :

Option A:

1. Sensory neurons are the nerves that send information to the brain.
2. Physical and chemical inputs from the environment activate the sensory neurons.
3. Sensory neurons do not carry signals from the spinal cord to the muscles.

Option B:

1. Motor neurons consist of a long axon and short dendrites.
2. Motor neurons carry signals from the Central nervous system to effectors.
3. Motor neurons do not carry signals from receptors to the spinal cord.

Final Answer: The true statements are that the sudden action in response to something in the environment is called reflex action and the path through which signals are transmitted from a receptor to a muscle or a gland is called the reflex arc.