What subject is primarily represented by the term "bio-"?

The term "bio-" is derived from the Greek word "bios," which means "life." It primarily indicates a connection to life and living organisms, making it most closely associated with life sciences. This encompasses various fields that study living beings, such as biology, ecology, and medicine.

In contrast, the other subjects listed—mathematics, earth sciences, and physical sciences—focus on non-living systems and abstract concepts (in the case of mathematics) or the physical aspects of the Earth and universe. Therefore, "bio-" specifically highlights the study of life and living processes, reinforcing its primary representation in the life sciences.