UGC NET Questions (Paper – 1)

The ozone layer is particularly effective at absorbing biologically harmful UV-B radiation from the sun. Without this filtering,much higher levels of UV-B would reach Earth’s surface. This would greatly increase the incidence of skin cancer,eye damage and harm to other organisms. Hence absorption of ultraviolet-B radiation is the key protective function described in the question.

Option A:
Ultraviolet-B radiation has enough energy to damage DNA and biological tissues. The ozone layer absorbs most of this band,thereby shielding living organisms. Because the question refers specifically to the protective role of the ozone layer,UV-B is the correct type of radiation.

Option B:
Infrared radiation is associated mainly with heat and plays a role in the greenhouse effect. The ozone layer is not primarily known for absorbing infrared radiation. Therefore this option does not match the protective function highlighted in the stem.

Option C:
Visible light is the portion of the spectrum that enables human vision. Most visible light passes through the atmosphere with little absorption by ozone. Since the ozone layer’s key biological protection is not related to visible light,this option is inappropriate.

Option D:
Radio waves are long wavelength electromagnetic waves used in communication. They are not strongly absorbed by the ozone layer and are not especially harmful to living tissues at natural levels. Thus they are unrelated to the protective role mentioned in the question.