08: The Nervous System : Icse-x-biology

Change Unit Change Subject Last Menu

ICSE-X-Biology

08: The Nervous System

with Solutions - page 2

Note: Please signup/signin free to get personalized experience.

Note: Please signup/signin free to get personalized experience.

10 minutes can boost your percentage by 10%

Note: Please signup/signin free to get personalized experience.

#1-d
Name the cells of the retina and their respective pigments which get activated (1) in the dark and (2) in the light.
digAnsr: I
Ans : In the dark: Cells - rod cells, Pigment - rhodopsin
In the light: Cells - cone cells, Pigment - iodopsin

Qstn #2
With reference to the human ear, answer the questions that follow:

#2-a
Give the technical term for the structure found in the inner ear.
Ans : The middle ear or membranous labyrinth has two structures inside it, the cochlea and the semi-circular canals.

#2-b
Name the three small bones present in the middle ear. What is the biological term for them collectively?
Ans : Malleus, incus and stapes

#2-c
Name the part of the ear associated with (1) static balance (2) hearing (3) dynamic balance. (d) Name the nerve, which transmits messages from the ear to the brain.
Ans : Static balance - Utriculus and sacculus (inner ear)
Hearing - Internal ear Dynamic balance - Semi-circular canals (inner ear) Collectively they are termed as ossicles.

Qstn #3
The figure below compares a part of our eye with a part of a photographic camera.

#3-a
name the corresponding parts of the eye the camera shown here that are comparable in function.
Ans : Cornea is comparable to the lens cover of the camera. The iris and pupil act like the aperture of a camera.

#3-b
Explain the mode of working and the functions of the parts of the eye mentioned above
Ans : The cornea is the eye's main focusing element. It takes widely diverging rays of light and bends them through the pupil; the rays are further converged by the lens.

Qstn #4
Given below is a diagram depicting a defect of the human eye. Study the same and answer the questions that follow:

#4-a
Name the defect shown in the diagram
Ans : Myopia

#4-b
Give two possible reasons for this defect
Ans : The two possible reasons for myopia are either the eye ball is lengthened from front to back or the lens is too curved.

#4-c
Name the parts labelled 1 to 4
Ans : 1-vitreous humour, 2-blind spot, 3-lens, 4-pupil

#4-d
Name the type of lens used to correct this eye defect
Ans : Concave lens

#4-e
Draw a labelled diagram to show how the above mentioned defect is rectified using the lens named above.
Ans :

Qstn #5
The figure below is the sectional view of a part of the skull showing s sense organ: