Which branch of biology focuses on the study of heredity and variation in organisms?

The branch of biology that focuses on the study of heredity and variation in organisms is genetics. Genetics examines how traits and characteristics are passed down from one generation to the next through genes, which are segments of DNA. This field explores concepts such as inheritance patterns, genetic variation, and the molecular mechanisms underlying these processes. By understanding genetics, scientists can investigate how specific traits are inherited, how genetic disorders occur, and how evolutionary processes influence the variation within and between species.

The other branches listed have distinct focuses and do not primarily deal with heredity and variation. Evolution studies the changes in species over time, botany is the study of plants, and microbiology focuses on microorganisms. While each of these fields may touch upon concepts of variation in a broader sense, they do not focus specifically on heredity and genetic inheritance in the way genetics does.