What is the primary role of the ozone layer in the atmosphere?

• A. To absorb harmful UV radiation
• B. To trap greenhouse gases
• C. To regulate global temperatures
• D. To provide oxygen for breathing

Answer: (A)

The primary role of the ozone layer in the atmosphere is to absorb harmful UV (ultraviolet) radiation. The ozone layer is comprised of ozone (O3) molecules located in the stratosphere and serves as a protective shield for the Earth. By absorbing a significant amount of UV radiation from the sun, the ozone layer helps prevent these high-energy rays from reaching the Earth’s surface, where they can cause detrimental effects on living organisms, including skin cancers in humans and damage to crops and aquatic ecosystems.

This protective function is critical because excessive UV radiation can lead to mutations in DNA, adversely affecting both human health and the environment. The concentration of ozone in the stratosphere is specifically designed to target these harmful UV wavelengths, thus playing a vital role in maintaining ecological balance.

The other choices, while related to atmospheric processes, do not correctly describe the primary function of the ozone layer. For example, trapping greenhouse gases is a responsibility more associated with the lower atmosphere, particularly the troposphere, rather than the ozone layer. Similarly, regulating global temperatures and providing oxygen for breathing are functions tied to broader atmospheric dynamics and the biosphere, rather than the specific protective role of the ozone layer.