Cornea, Choroid, Lens, Aqueous humour, Iris, Vitreous humour — how many of these are refractory media of the eyeball?
(a) 3
(b) 4
(c) 5
(d) 6
WBBSE
Class X
Life Science
01 (d) Nervous System
2023
(b) 4
Explanation
The refractory media of the human eye are the transparent structures that help to refract (bend) light rays to focus them on the retina. These include the cornea, aqueous humour, lens, and vitreous humour. The cornea forms the main refractive surface, while the other three media fine‑tune the focus of light. The choroid and iris are not refracting media; they provide nourishment and regulate light entry, respectively.
Related Questions
More WBBSE Easy level questions
1/12
Q.
Write two differences between axon and dendron.
A.
Axon Dendron 1. Single, long process in a neuron. 1. Several, short...
Q.
Draw a scientific diagram of the vertical section of a human eyeball and label the...
A.
Vertical section of a human eyeball Or The anaphase stage of mitotic...
Q.
Which of the following is not a structural feature of an Axon? (a) Node of...
A.
(c) Nissl granule Explanation A neuron consists of three parts — cell...
Q.
Write the names of two structural parts of axon.
A.
Two parts are: Axon hillock Myelin sheath Explanation: The axon hillock is...
Q.
Blind spot is the part of the eye devoid of light sensitive cells formed at...
A.
True. Explanation: The blind spot is an area on the retina where...
Q.
Accommodation is the ability of the retina of the eye to adjust the focal length...
A.
False. Explanation: Accommodation is the ability of the lens of the eye...
Q.
Name any two structural parts of Neurone
A.
Axon and Dendron. Explanation: The axon carries impulses away from the cell...
Q.
Explain the causes of Myopia and Hyperopia
A.
Defect Cause Myopia (Near-sightedness) This defect occurs when the eyeball becomes too...
Q.
Choose the odd one and write it: Olfactory nerve, Vagus nerve, Optic nerve, Auditory nerve
A.
Vagus nerve Explanation: Vagus nerve is a mixed nerve (both sensory and...
Q.
State True or False: The focal length of lens increases in case of seeing distant...
A.
True Explanation: When seeing distant objects, the ciliary muscles relax, causing the...
Q.
Reflex action is fast, spontaneous and ____.
A.
involuntary Explanation Reflex actions are rapid and involuntary responses to stimuli that...
Q.
Decide which of the following sequence is correct — (a) Receptor → Effector → Sensory...
A.
(c) Receptor → Sensory Nerve → Nerve Centre → Motor Nerve →...