Which term best describes the study of how biological traits change over generations within populations?

• A. Evolution
• B. Euphotic Zone
• C. Food
• D. Endothermic

Answer: (A)

Understanding evolution means looking at how heritable traits in a population change over generations due to genetic variation and forces like natural selection, genetic drift, mutation, and gene flow. This shift in allele frequencies over time explains how populations adapt to their environments and can lead to new species. That makes evolution the best term for describing the study of trait changes across generations.

The other options don’t fit this idea. The euphotic zone is just the sunlit layer of the ocean where photosynthesis happens, a habitat description rather than a process of trait change. Food refers to nutrients and energy sources, not a study of how traits evolve. Endothermic describes a physiological trait about body temperature regulation, not the study of how traits change across generations.