- A Increased plant growth resulting from a noticeably higher rate of photosynthetic activity overall under most conditions encountered
- B Increased skin cancer (melanoma), cataracts, immune suppression, and damage to marine ecosystems (phytoplankton)
- C Cooler surface temperatures caused by greater UV reflection off high-altitude cloud cover as frequently observed in practice
- D Increased global rainfall caused by enhanced ionization occurring within the upper atmosphere in many documented cases
Correct answer: B. Increased skin cancer (melanoma), cataracts, immune suppression, and damage to marine ecosystems (phytoplankton)
Explanation: UV-B causes DNA damage (thymine dimers), which the ozone layer normally prevents. Increased UV-B exposure leads to: (1) Skin cancer (melanoma, BCC, SCC); (2) Cataracts; (3) Immune suppression; (4) Damage to phytoplankton (base of marine food chain); (5) Reduced agricultural yields.
Concept context
Pollution, global warming, ozone depletion, deforestation, and sustainability. Important for NEET and general awareness.