The depletion of the ozone layer will result in the earth surface receiving more

Step 1: Analyze the question The question asks which type of radiation reaches the earth's surface in greater amounts when the ozone layer thins out.

Step 2: Explain the concept The ozone layer (O₃) is found in the stratosphere. Its main job is to absorb most of the harmful ultraviolet (UV) radiation, especially UV-B, from the sun. Chemicals such as CFCs (chlorofluorocarbons, from old refrigerators, aerosol sprays and air conditioners) break down ozone molecules and thin the layer.

Step 3: Work through the options

• A. Gamma rays: These are almost entirely absorbed higher in the atmosphere, and ozone is not the main shield against them. Not correct.
• B. Infra-red rays: These are heat rays. They are related to the greenhouse effect and global warming, not to ozone depletion. Not correct.
• C. Ultraviolet rays: Ozone absorbs these. When the layer is depleted, more UV reaches the earth. Correct.
• D. X-rays: These are also absorbed high in the atmosphere, and ozone is not what blocks them. Not correct.

Step 4: Answer The correct answer is C. ultraviolet rays.

Effects of increased UV on living things:

• Skin cancer and sunburn in humans
• Cataracts (eye damage)
• Reduced crop yields and damage to plankton
• Weakened immune systems

Exam tip: Remember "Ozone = UV shield" and "CO₂ = infra-red/heat trap." WASSCE often tests the difference between ozone depletion (UV) and the greenhouse effect (heat/infra-red), so keep them separate in your mind.