What role does the ozone layer play in protecting living organisms?

• A. It reflects most sunlight
• B. It absorbs harmful ultraviolet radiation
• C. It generates heat to warm the Earth
• D. It blocks all forms of electromagnetic radiation

Answer: (B)

The correct choice highlights the ozone layer's critical function in absorbing harmful ultraviolet (UV) radiation from the Sun. This absorption is vital because UV radiation can cause various detrimental effects on living organisms, including skin cancer in humans, cataracts, and other health issues. Additionally, UV radiation can severely affect ecosystems, damaging phytoplankton in oceans, which are essential for the food chain and produce a significant portion of the Earth's oxygen.

While it may seem that reflecting sunlight could protect living organisms, this isn't the primary role of the ozone layer. Instead, the ozone layer specifically interacts with UV radiation, which is more harmful than visible light. Generating heat to warm the Earth does not accurately describe the properties of the ozone layer; instead, it plays a role in the atmosphere's thermal characteristics. Lastly, the assertion that the ozone layer blocks all forms of electromagnetic radiation is incorrect because it primarily focuses on UV radiation, allowing other wavelengths of the electromagnetic spectrum, like visible light and infrared, to pass through. Thus, the primary protective function of the ozone layer is its ability to absorb harmful UV radiation.