In the human eye, the visual acuity is highest at:

1. Macula lutea

2. Optic disc

3. Fovea centralis

4. Optic chiasma

Reissner's membrane separates:
1. Scala vestibuli and Scala media
2. Tympanic cavity and Pharynx
3. Fenestra rotundus and Fenestra ovalis
4. Scala media and Scala tympani

The resting membrane potential is established primarily due to:
1. Sodium-potassium pump
2. Efflux of potassium
3. Influx of sodium
4. Influx of chloride

A characteristic of human cornea is :
1. absence of blood circulation 
2. cause cataract in old age
3. has lacrimal glands for secreting tears
4. secreted by conjunctiva and glandular layer

Most sensory receptors function by producing depolarising potentials. Which of the following function by hyperpolarization rather than depolarization ?

1. proprioceptors
2. nociceptors
3. olfactory receptors
4. rods and cones

The depolarization of the axonal membrane is due to:

1. Influx of sodium ions

2. Efflux of sodium ions

3. Influx of potassium ions

4. Efflux of the potassium ions

Immediately after an action potential has peaked, which cellular gates open?

1. Sodium
2. Chloride
3. Calcium
4. Potassium

The stapes sends its vibrations to 
1. Incus 
2. Round window
3. Tympanic membrane
4. Oval window

In a chemical synapse, when an impulse arrives at the axon terminal, it:
1. leads to the opening of the calcium channels at the post-synaptic membrane.
2. Stimulates the fusion of synaptic vesicles towards the pre-synaptic membrane.
3. causes the binding of the neurotransmitter of its receptors on the post-synaptic neuron.
4. activates the opening of the potassium channels in the axon terminal.

Above the rows of hair cells of Organ of Corti, there is a thin elastic membrane called:
1. Reissner's membrane
2. Basilar membrane
3. Tectorial membrane
4. Tympanic membrane