In the mammalian eye, the ‘fovea’ is the center of the visual field, where?
1. high density of cones occur, but has no rods
2. the optic nerve leaves the eye
3. only rods are present
4. more rods than cones are found
A gymnast is able to balance his body upside down even in total darkness because of:
1. cochlea
2. vestibular apparatus
3. tectorial membrane
4. the organ of Corti
Which one of the following statements is not correct?
1. | Retinal is the light-absorbing portion of visual photo pigments |
2. | In retina, the rods have the photopigments rhodopsin while cones have three different photopigments. |
3. | Retinal is a derivative of Vitamin C |
4. | Rhodopsin is the purplish protein present in rods only. |
Parts A, B, C and D of the human eye are shown in the diagram. Select the option which gives correct identification along with its functions/characteristics:
1. | B-blind spot has only a few rods and cones |
2. | C-aqueous chamber reflects the light which does not pass through the lens |
3. | D-choroid- its anterior part forms the ciliary body |
4. | A-retina - contains photoreceptors rods and cones |
Which part of the human ear plays no role in hearing as such but is otherwise very much required?
1. Eustachian tube
2. Organ of Corti
3. Vestibular apparatus
4. Ear ossicles
A person entering an empty room suddenly finds a snake right in front on opening the door. Which one of the following is likely to happen in his neurohormonal control system?
1. | Sympathetic nervous system activated releasing epinephrine and norepinephrine from adrenal medulla |
2. | Neurotransmitters diffuse rapidly across the cleft and transmit a nerve impulse |
3. | Hypothalamus activates the parasympathetic division of the brain |
4. | Sympathetic nervous system is activated releasing epinephrine and norepinephrine from the adrenal cortex |
1. vitamin-C
2. vitamin-D
3. vitamin-A
4. vitamin-B
Given below is a diagrammatic cross-section of a single loop of human cochlea.
1. | B: Tectorial membrane C: Perilymph D: Secretory cells |
2. | C: Endolymph D: Sensory hair cells A: Serum |
3. | D: Sensory hair cells A: Endolymph B: Tectorial membrane |
4. | A: Perilymph B: Tectorial membrane C: Endolymph |
Which one of the following is the correct difference between rod cells and cone cells of our retina?
Features | Rod cells | Cone cells | |
(a) | Visual acuity | High | Low |
(b) | Visual pigment contained | Iodopsin | Rhodopsin |
(c) | Overall function | Vision in poor light | Colour vision and detailed vision in bright light |
(d) | Distribution | More concentrated in centre of retina | Evenly distributed all over retina |
1. a
2. b
3. c
4. d
Bowman's glands are located in the:
1. proximal end of uriniferous tubules
2. anterior pituitary
3. female reproductive system of cockroach
4. olfactory epithelium of our nose