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
Which of the following types of cells are found in retina ?
1. Neuroglial cell
3. Schwann cell
4. Amacrine cell
5. Purkinje cell
The black pigment in the eye which reduces the internal reflection is located in
(a) retina
(c) cornea
(b) iris
(d) sclerotic.
Which of the following is true for the function of labelled parts in the diagram below?
(1) A - Blind spot - Image is formed here
(2) B - Fovea - No visual activity is present
(3) C - Cornea - Helps to hold lens in place
(4) D - Iris - Visible coloured portion of eye
How macula lutea and corpus luteum are related ?
(1) Contribute in maintain pregnancy
(2) Both are a source of hormones
(3) Both are characterised by their yellow colour
(4) Both are found in human ovaries
The cornea is a very important component of the human eye. The main function of the cornea is to
(1) bend the light before it reaches the lens
(2) provide structural support to the eye
(3) contain a concentrated amount of cone cells in the correct orientation
(4) change the shape of the lens to enable the image to be focused on the retina