The purplish red pigment rhodopsin contained in the rods type of photoreceptor cells of the human eyes is a derivative of
1. vitamin-C
2. vitamin-D
3. vitamin-A
4. vitamin-B

When a neuron is at resting state, i.e., not conducting any impulse, the axonal membrane is

The nerve centres which control the body temperature and the urge for eating are contained in
1. hypothalamus
2. pons
3. cerebellum
4. thalamus

Alzheimer’s disease in humans is associated with the deficiency of
1. dopamine
2. glutamic acid
3. acetylcholine
4. Gamma Amino Butyric Acid (GABA)

Which one of the following does not act as a neurotransmitter?
1. Acetylcholine
2. Epinephrine
3. Norepinephrine
4. Cortisone

Which of the following pesticides is an acetylcholinesterase inhibitor?
1. Aldrin
2. BHC
3. Endosulfan
4. Malathion

Identify the correct statement:
1. In amniotes, last nerve is spinal accessory.
2. In non-amniotes, last nerve is vagus.
3. Optic is shortest nerve.
4. Olfactory nerves have mixed fibres.

A person is wearing spectacles with concave lenses for correcting vision. While not using the glasses, the image of a distant object in his case will be formed:
1. on the blind spot
2. behind the retina
3. in front of the retina
4. on the yellow spot

Unidirectional transmission of a nerve impulse through nerve fibre is due to the fact that
1. nerve fibre is insulated by a medullary sheath
2. sodium pump starts operating only at the cyton and then continues into the nerve fibre
3. neurotransmitters are released by dendrites and not by axon endings
4. neurotransmitters are released by the axon endings and not by dendrites.

Given below is a table comparing the effects of sympathetic and parasympathetic nervous system for four feature (a-d). Which one feature is correctly described?