Previous Year Question
Ozone protects biosphere from
Infra-red rays
Ultraviolet rays
X-rays
Gama rays
Correct Answer: B
Detailed Solution
The concentration of Ozone is relatively high in the Stratosphere, forming what is commonly called the Ozone Layer.
The Ozone Layer absorbs a significant portion of harmful Ultraviolet (UV) Radiation coming from the Sun and thereby protects life on Earth.
Solar UV Radiation is mainly divided into UV-A, UV-B and UV-C.
UV-C is extremely harmful, but it is almost completely absorbed by atmospheric Oxygen and Ozone.
Most UV-B is also absorbed by the Ozone Layer. The UV-B that reaches the Earth's surface can cause DNA damage, skin cancer and cataracts.
Most UV-A passes through the Ozone Layer and reaches the Earth's surface.
Therefore, from the viewpoint of protecting the Biosphere, the most important function of the Ozone Layer is to block harmful Ultraviolet Radiation, particularly UV-B and UV-C.