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
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
Good vision depends on adequate intake of carotene rich food.
Select the best option from the following statements.
I. Vitamin-A derivatives are formed from carotene.
II. The photopigments are embedded in the membrane discs of the inner segment.
III. Retinal is a derivative of vitamin-A.
IV. Retinal is a light absorbing part of all the visual photopigments.
(1) (I) and (II)
(2) (I), (III) and (IV)
(3) (I) and (III)
(4) (II), (III) and (IV)
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
Cornea transplant in humans is almost never rejected. This is because
1. its cells are least penetrable by bacteria
2. it has no blood supply
3. it is composed of enucleated cells
4. it is a non-living layer