Which of the following minerals reduces the excitability of nerves and muscles?

1. Potassium

2. Sodium

3. Magnesium

4. Manganese

A frog has its brain crushed. But when pinched on the leg. The leg draws away. It is an

example of

1. neurotransmitter induced responsce

2. simple reflex

3. conditioned reflex

4. automated motor response.

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 has 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 relesed 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?

The black pigment in the eye which reduces the internal reflection is located in

(a) retina

(c) cornea

(b) iris

(d) sclerotic.

Hearing impairment affects which part of brain?

(1) Frontal lobe

(2) Parietal lobe 

(3) Temporal lobe

(4) Cerebellum

One common example of simplex reflex is 
(1) tying your shoe laces while talking to another person and not looking at them 

(2) watering of mouth at the sight of a favourite food 

(3) climbing up a stairs in dark without stumbling

(4) closing of eyes when strong light is flashed across them.