In mammalian eye, the 'fovea' is the center of the visual field, where

1. high density of cones occur, but has no rods

2. the optic nerve leaves the eye

3. only rods are present

4. more rods than cones are found

Stimulation of a muscle fibre by a motor neuron occurs at

1. the neuromuscular junction

2. the transverse tubules

3. the myofibril

4. the sacroplasmic reticulum

Injury localised to the hypothalams would most likely disrupt

1. short term memory 

2. coordination during locomotion 

3. executive function, such as decision making 

4. regulation of body temperature 

Which one of the following statements is not correct?

1. Retinal is the light absorbing portion of visual photopigments 

2. In retina the rods have the photopigment rhodopsin, while cones have three different

photopigments

3. Retinal is a derivative of vitamin-C

4. Rhodopsin is the purplish red protein present in rods only 

A diagram showing axon terminal and synapse is given. Identify correctly A-D.

1. A- Receptor                  C-synaptic Vesicles

2. B-Synaptic connection   D-K⁺

3. A-Neurotransmitter        B-Synaptic cleft

4. C-neurotransmitter        D-Ca²⁺        

Parts A, B, C and D of the human eyes are shown in the diagram. Select the option

which gives correct identification along with its functions/characteristics

1. A-retina-contains photoreceptors-rods and cones

2. B-blind spot-has only a few rods and cones

3. C-aqueous chamber-reflects the light which does not pass through the lens

4. D-choroidits anterior part forms ciliary body

Which part of the human ear plays no role in hearing as such but is otherwise very much

required?

1. Eustachian tube

2. Organ of Corti

3. Vestibular apparatus

4. Ear ossicles

A person entering an empty room suddenly finds a snake right in front on opening the

door. Which one of the following is likely to happen in his neurohormonal control system?

1. Sympathetic nervous system is activated releasing epinephrine and norepinephrine

from adrenal medulla

2. Neurotransmitters diffuse rapidly across the cleft and transmit a nerve impulse

3. Hypothalamus activates the parasympathetic division of brain

4. Sympathetic nervous system is activated releasing epinephrine and norepinephrine

from adrenal cortex

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 an resting state, ie, not conducting any impulse, the axonal membrane

is

1. equally permeable to both Na⁺ and K⁺ ions

2. impermeable to both Na⁺ and K⁺ ions

3. comparatively more permeable to K⁺ ions and nearly impermeable to Na⁺ ions

4. comparatively more permeable to Na⁺ ions and nearly impermeable to K⁺ ions