Which of the following is the part of mid brain of rabbit?

• Diencephalon

• Cerebrum

• Corpora quadrigemina

• None of the above

Now-a-days cornea transplantation is very popular. The reason is that it

• is easy to preserve

• transplanted very easily

• can be easily obtained

• does not link with blood supply and immune system

Unidirectional transmission of a nerve impulse through nerve fibre is due to the fact that

• nerve fibre is insulated by a medullary sheath

• sodium pump starts operating only at the cyton and then continues into the nerve fibre

• neurotransmitters are released by dendrites and not by axon endings

• neurotransmitters are released by the axon endings and not by dendrites.

224.

Cornea transplant in humans is almost never rejected. This is because

• it is composed of enucleated cells

• it is a non-living layer

• its cells are least penetrable by bacteria

• it has no blood supply

Assertion : All motor neurons are efferent neurons.

Reason : Motor neurons conduct nerve impulses from the spinal cord to the brain.

• If both assertion and reason are true and reason is the correct explanation of assertion

• If both assertion and reason are true but reason is not the correct explanation of assertion

• If assertion is true but reason is false.

• If both assertion and reason are false

Given is the diagrammatic representation of the sectional view of cochlea. Select the correct option regarding it.

• A - Organ of corti-responsible for maintenance of balance of the body and posture.

• B- Scala vestibuli-filled with perilymph that ends at the oval window.

• C- Scala tympani-terminates at the round window which opens to the middle ear.

• D- Basilar membrane - nerve impulses are generated against it.

Assertion: The optic nerves leave the eye at the point called blind spot.

Reason: Only cone are densely packed at the blind spot, hence is the name.

• If both assertion and reason are true and reason is the correct explanation of assertion.

• If both assertion and reason are true but reason is not the correct explanation of assertion.

• If assertion is true but reason is false.

• If both assertion and reason are false.

Which of the following is correctly labelled

• A: Reissner's membrane

• B: Scala vestibuli

•  C : Basilar membrane

• D: Tectorial membrane

The release of chemical messenger from synaptic vesicles is under the influence of these ion(s).

• Cl^- 

• Fe and S²⁺

• Ca²⁺

• Mg²⁺ and Sr²⁺

Assertion: Mylein sheath insulates the nerve fibre and prevents its depolarisation.

Reason: Nerve impulses are conducted more rapidly in non - myelinated nerve fibres than in myelinated ones.

• If both assertion and reason are true and reason is the correct explanation of assertion.

• If both assertion and reason are true but reason is not the correct explanation of assertion.

• If assertion is true but reason is false.

• If both assertion and reason are false