Question

Why is it said that – ?
(a) The ozone layer is a protective shell of the earth.
(b) Water is life.
(c) Seawater is useful even though it is not potable.

Answer 1

a)The ozone layer acts as a filter for the shorter wavelength and highly hazardous ultraviolet radiation (UVR) from the sun, protecting life on Earth from its potentially harmful effects.


b)Water is essential simply because it's a liquid at Earth-like temperatures. Because it flows, water provides an efficient way to transfer substances from a cell to the cell's environment.

c)
Human kidneys can only make urine that is less salty than salt water. Therefore, to get rid of all the excess salt taken in by drinking seawater, you have to urinate more water than you drank. Eventually, you die of dehydration even as you become thirstier.

Answer 2

Dear Student,

◆ Answers -

(a) The ozone layer is a protective shell of the earth.

• Ozone protects the earth from harmful radiations
• Our skin is prevented from contact with UV-B radiation by ozone.
• Hence, it's called protective shell of earth.

(b) Water is life -

• Water is essential for our daily activities.
• All organisms are made of most part by water.
• Hence, water is called life.

(c) Seawater is useful even though it is not potable.

• Even though we dont drink sea water, it is essential for aquatic life which we eat as food.
• Also it grows phytoplanktons which release oxygen in air.
• Hence, seawater is useful.

Thanks dear. Hope this helps you...