Unmyelinated nerve fiber is:

1. Not enclosed by a Schwann cell and hence not enclosed by a myelin sheath.

2. Enclosed by a Schwann cell that does not form a myelin sheath.

3. Not enclosed by a Schwann cell but enclosed by a myelin sheath formed by oligodendrocytes.

4. Not found in the autonomous and the somatic neural system.

The brain stem does not include :
1. Mid-brain 
2. Medulla oblongata
3. Pons Varolii
4. Cerebellum 

Which of the following is a major coordinating center for sensory and motor signaling for the cerebrum?
1. Hypothalamus
2. Thalamus
3. Corpora quadrigemina
4. Amygdala

The sensory neuron enters the spinal cord through:
1. The dorsal root of the spinal nerve
2. The ventral root of the spinal nerve
3. Either dorsal or ventral root depending on the point of origin 
4. Both dorsal and ventral roots of the spinal nerves

From inside to outside the correct order of the following cells in the retina would be:
1. Ganglion cells - Photoreceptor cells - Bipolar cells
2. Ganglion cells - Bipolar cells - Photoreceptor cells
3. Bipolar cells - Photoreceptor cells - Ganglion cells
4. Photoreceptor cells - Ganglion cells - Bipolar cells

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