Which of the following studies the science of heredity and variation of inherited traits among related organisms?

The study of heredity and the variation of inherited traits among related organisms is known as genetics. This field focuses on understanding how traits are passed from parents to offspring through genes, the basic units of heredity. Genetics involves the analysis of DNA, gene expressions, and the ways in which traits can be influenced by environmental factors, allowing scientists to study both hereditary conditions and evolutionary processes.

Other fields mentioned in the options have distinct focuses that do not pertain directly to heredity and inherited traits. Botany studies plant life, ecology examines interactions between organisms and their environments, and biochemistry explores the chemical processes within and related to living organisms. While these fields can have overlapping interests with genetics, particularly in understanding how certain traits may impact an organism's adaptability or survival, they do not focus primarily on the principles of heredity and genetic variation.