The changes of living organisms over generation is referred to as

1. Analyze the question The question asks for the term describing the change of living organisms (all living things, not only humans) over successive generations.

2. Explain the concept Evolution is the gradual change in the inherited characteristics of populations of organisms over many generations. The term for this in biology is organic evolution, because "organic" refers to living things. It covers how species arise, change and adapt through processes such as natural selection, mutation and genetic variation.

3. Evaluate each option

• A. Human evolution: This covers only the evolution of humans (Homo sapiens) from earlier hominids. It is too narrow, because the question refers to living organisms in general.
• B. Organic evolution: This is the change in living organisms over generations, giving rise to new species and adaptations. This fits the question exactly.
• C. Physical evolution: This is not a standard biological term for the change of living organisms.
• D. Chemical evolution: This refers to the formation of complex organic molecules from simple inorganic ones on the early Earth, before life began. It is about the origin of life, not the change of living organisms.

4. Answer The correct option is B. organic evolution.

5. Exam tip Link the words to their meaning:

• Chemical evolution = chemicals forming the first life.
• Organic evolution = living things changing over time.
• Human evolution = humans only.

If a question says "living organisms" and "generations", think "organic evolution".