Tag: human brain and sense organs

Questions Related to human brain and sense organs

Match column I with column II and select the correct option from the codes given below.

Column I Column II
A. Cornea (i) Provides opening for light to enter
B. Iris (ii) Transducens blue, green and red light
C. Lens (iii) Controls the amount of light that enters
D. Optic nerves (iv) Alters the shape of lens
E. Pupil (v) Transmit information to the CNS
F. Ciliary muscles (vi) Focus light directly on retina
G. Fovea (vii) Bends light and protects inner eye


biology human brain and sense organs introduction to sense organs eyes and their function the structure and function of the eye

  1. A - (vii), B - (iii), C - (vi), D - (v), E - (i), F - (iv), G - (ii)

  2. A - (i), B - (ii), C - (iii), D - (iv), E - (v), F - (vi), G - (vii)

  3. A - (vii), B - (vi), C - (v), D - i(v), E - (iii), F - (ii), G - (i)

  4. A - (vii), B - (iv), C - (vi), D - (v), E - (i), F - (iii), G - (ii)

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Correct Option: A

Rhodopsin is found in

biology human brain and sense organs introduction to sense organs eyes and their function the structure and function of the eye

  1. Rods only

  2. Whole of retina

  3. Cones only

  4. Ganglion cells

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Correct Option: A
Explanation:

Rhodopsin is found in specialized light receptor cells called rods. These are light-sensitive tissue present in the retina. They provide vision in low light. Other light receptor cells in the retina, called cones, are responsible for vision in bright light.

Thus, the correct answer is 'rods only.'

The portion of the eye which is differently coloured in different people and gives characteristically coloured eyes is the

biology human brain and sense organs introduction to sense organs eyes and their function the structure and function of the eye

  1. Retina

  2. Cornea

  3. Sclera

  4. Iris

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Correct Option: D
Explanation:

Retina is the innermost layers of the eyeball. The cornea is the transparent anterior window of the outer layer of the eyeball located within otherwise opaque sclera. Iris is the colored part of the eye that imparts characteristic color of eyes to different people. 

So, the correct answer is option D.

A comb-like vascular structure pectin, used for nourishment and focussing in the eyes of

biology human brain and sense organs introduction to sense organs eyes and their function the structure and function of the eye

  1. Amphibians

  2. Birds

  3. Mammals

  4. Reptiles

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Correct Option: B
Explanation:

In the eye of the bird, a comb-like structure is present. It is called as pectin. It is soft and vascular. It is a rectangular plate. It projects into the vitreous humor from the blind spot. So, the correct answer is option B.

The entry of light in a photographic camera is controlled by the shutter and iris diaphragm, comparable structure in human eye are

biology human brain and sense organs introduction to sense organs eyes and their function the structure and function of the eye

  1. Cornea and iris

  2. Eyelids and iris

  3. Ciliary muscles and pupil

  4. Ciliary body and iris

Show answer
Correct Option: B
Explanation:

Iris is the part of the eye, which acts like the diaphragm of a camera, dilating and constricting the pupil to allow more or less light into the eye. The iris works like a shutter in a camera. It has the ability to enlarge and shrink, depending on how much light is entering the eye.
The two eyelids act to protect the front of the eye and excessive light by their closure. The inner layer of the cornea is made up of transparent tissue, which allows light to pass. The pupil is the dark opening in the centre of the coloured iris, that controls how much light enters the eye. The ciliary body is a structure located behind the iris which produces aqueous fluid that fills the front part of the eye and thus maintains the eye pressure. It also allows focusing of the lens. 

Thus, the correct answer is the option (B).

Which animal have porphyropsin instead of pigment rhodopsin in rods? 

biology human brain and sense organs introduction to sense organs eyes and their function the structure and function of the eye

  1. Fish

  2. Birds

  3. Reptiles

  4. Mammals

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Correct Option: A
Explanation:

In the rods of fresh water fishes, rhodopsin is replaced by the purple photolabile pigment porphyropsin. This participates in a retinal cycle identical in form with that of rhodopsin, but in which new carotenoids replace retinene and vitamin A.

The retina of the eye acts as a

biology human brain and sense organs introduction to sense organs eyes and their function the structure and function of the eye

  1. Lens of the camera

  2. Aperture of the camera

  3. Film of the camera

  4. Shutter of the camera

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Correct Option: C
Explanation:

The back of the eye is lined by a layer called as the retina, which acts like the film inside a camera. The retina is a thin layer of nerve tissue, that contains photoreceptors. Photoreceptors convert light rays into electrical impulses, which are then sent through the optic nerve to the brain, where an image is perceived. As with a camera, if the film is bad in the eye (i.e., the retina is damaged or diseased), no matter how well the rest of the eye is functioning, a good picture is not possible.

Ora serrata is

biology human brain and sense organs introduction to sense organs eyes and their function the structure and function of the eye

  1. A serrated junction between the retina and ciliary body

  2. Oral cavity of protochoradates

  3. Gland present in oral cavity of frog

  4. Present in utriculus of ear

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Correct Option: A
Explanation:

The ora Serrata is a toothlike junction between the peripheral retina and the pars plana and is composed of forward extensions of the retina and backward extensions of the ciliary body. So, the correct answer is option A.

The normal eye which can sufficiently refract light rays from an object 20 ft. (6 mt.) away to focus clear object on retina is called as

biology human brain and sense organs introduction to sense organs eyes and their function the structure and function of the eye

  1. Myopic

  2. Emmetropic

  3. Hypermetrophic

  4. No specific name

Show answer
Correct Option: B
Explanation:

A myopic eyed person focuses the light rays from a distant object in front of the retina, it can not focus distant objects sharply on the retina. Emmetropic eyes are characterized by sharp focusing of parallel light rays from distant objects on the retina when the ciliary muscle is completely relaxed to make the person see all the distant objects clearly. Hypermetropic eyes can not sufficiently bend the parallel light rays from the distant object to focus it on the retina in time.

The visual unit of a compound eye of an insect is

biology human brain and sense organs introduction to sense organs eyes and their function the structure and function of the eye

  1. Ommatidium

  2. Rods

  3. Rhabdom

  4. Cones

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Correct Option: A
Explanation:

The compound eyes of arthropods are composed of units called as ommatidia. An ommatidium contains a cluster of photoreceptor cells surrounded by support cells and pigment cells.