Which of the following is one of the five themes of science?

• A. Photosynthesis
• B. Evolution
• C. Mitosis
• D. DNA replication

Answer: (B)

Evolution ties together many areas of biology because it explains how life changes over time, how species are related, and how new traits arise through genetic variation and natural selection. It provides a unifying framework that connects genetics, anatomy, fossils, ecology, and behavior, helping us understand both the commonalities and the differences among living things.

The other options are specific processes within cells or metabolism rather than broad, cross-cutting themes. Photosynthesis is a biochemical pathway that captures light energy; mitosis is the process of cell division; DNA replication is the copying of genetic material. While essential for life, these are particular mechanisms, not overarching ideas that organize and unify many biological phenomena the way evolution does.