Biology Multiple Choice Questions on “Neural Control and Coordination – Eye-1”.
1. In which of these structures are the eyes located?
a) Glenoid cavity
b) Acetabulum
c) Pores
d) Orbits
Answer: d
Clarification: The eyes are located in two sockets present in the skull known as orbits. The orbits are bony cavities in the front part of the skull in which the eye and its appendages are accommodated and protected.
2. How many layers does the wall of the eyeball have?
a) 1
b) 2
c) 3
d) 4
Answer: c
Clarification: The wall of the eyeball has three layers. The outermost layer is known as the sclera. The middle layer is known as the choroid and it is bluish in color. The innermost layer is known as the retina.
3. What is the sclera composed of?
a) Mucoid connective tissue
b) Loose connective tissue
c) Dense connective tissue
d) Pigmented connective tissue
Answer: c
Clarification: The eyeball is surrounded by three layers. The sclera is the outermost opaque and fibrous layer that surrounds the eye. It is made up of dense connective tissue and provides protection and form.
4. What is the anterior portion of the sclera known as?
a) Cornea
b) Choroid
c) Retina
d) Iris
Answer: a
Clarification: The sclera is the outermost layer out of the three layers that surround the eyeball. The sclera is made up of dense connective tissue. The anterior portion of the sclera known as the cornea.
5. What is the middle layer of the eye known as?
a) Retina
b) Choroid
c) Cornea
d) Sclera
Answer: b
Clarification: The eyeball is surrounded by three layers, the outermost sclera, the middle choroid and the innermost retina. The choroid is rich in blood vessels to provide nourishment to the eye and is bluish.
6. The iris is a continuation of which of these structures?
a) Retina
b) Cornea
c) Ciliary body
d) Sclera
Answer: c
Clarification: The middle layer of the eye is known as the choroid layer. The choroid id thicker in the anterior portion of the eye and forms the ciliary body. The ciliary body continues forward to form the iris.
7. How many layers of neural cells does the retina possess?
a) 3
b) 2
c) 4
d) 1
Answer: a
Clarification: The retina is the innermost layer of the eyeball. It possesses three layers of neural cells which help in vision. These three layers are the ganglion cells, the bipolar cells and the photoreceptor cells.
8. Identify the part of the eye.
a) Cornea
b) Optic nerve
c) Blind spot
d) Fovea
Answer: d
Clarification: The diagram given is that of an eyeball. The indicated structure lies towards the back of the eye at its posterior pole, on the innermost layer that surrounds the eyeball. It is identified as the fovea.
9. Identify the part of the eye.
a) Ciliary bodies
b) Cornea
c) Iris
d) Lens
Answer: c
Clarification: In the given diagram of the eyeball, the indicated structure lies in the anterior part of the eye just above the lens. It is a continuation of the ciliary bodies and hence, is identified to be the iris.
10. Scotopic vision is a function of cone cells. True or false?
a) True
b) False
Answer: b
Clarification: Scotopic vision or twilight vision is a function of rod cells, while photopic vision or colored vision is a function of cone cells. The rod cells and cone cells are the photopigments present in the retina.
11. At which of these sites will you find a yellowish pigmented spot?
a) A
b) B
c) C
d) D
Answer: c
Clarification: In the given diagram of the eyeball, site C is the fovea. It is a central pit present in the yellowish pigmented spot known as the macula lutea. Visual acuity or resolution is the greatest at this spot.
12. What is retinal?
a) Aldehyde of opsin
b) Isomer of opsin
c) Aldehyde of vitamin A
d) Acid of riboflavin
Answer: c
Clarification: Retinal is an aldehyde of vitamin A and is a component of the light sensitive photopigments, along with opsin. It is present in the retina, which is the innermost layer surrounding the eye.
13. Which of these structures have a bluish appearance?
a) Sclera
b) Cornea
c) Choroid
d) Retina
Answer: c
Clarification: The eyeball is surrounded by three membranes-the outermost sclera, the middle choroid and the innermost retina. The choroid layer is rich in blood vessels and hence gives a bluish appearance.
14. The ciliary body is a part of which of these structures?
a) Choroid
b) Retina
c) Sclera
d) Macula lutea
Answer: a
Clarification: The eyeball is surrounded by three protective layers. The middle layer is known as the choroid, which is rich in blood vessels and has a bluish appearance. The ciliary body is a part of the choroid.
15. Which of these is not a characteristic of the iris?
a) It is opaque
b) It is a part of the sclera
c) It is a continuation of the ciliary bodies
d) It is pigmented
Answer: b
Clarification: The iris is not a part of the sclera, but a part of the middle layer of the eye, known as the choroid. It is opaque, pigmented and forms the colored part of the eye. The iris is a continuation of the ciliary bodies.