Any factor that can bring a change in the body of an organism is called:

1. Response
2. Stimulus
3. Reflex
4. Impulse

Gyri and sulci are richly found in :

1. Renal cortex
2. Cerebral cortex
3. Spinal cortex
4. Adrenal cortex

The figure given below shows a simple reflex, brought out by spinal cord, when a person touches a hot iron.

Which of the options given below will be correct for the receptor and effector in the diagram shown above ?

1. Iron and finger
2. Muscles and skin
3. Skin and muscles
4. Finger and arm

Assertion (A): Effectors are the part of our body which, on receiving stimulus, set up waves of impulses towards the central nervous system.

Reason (R): The specialized epithelial cells of certain organs are capable of receiving stimuli which can be light, sound, heat, pain, hunger, etc.

1. Both A and R are True
2. Both A and R are False
3. A is True and R is False.
4. A is False and R is True.