Question

what are the structures and functions of dna and rna?
how does your body transport oxygen? make sure to describe the kinds of blood vessels and the kind of protein that is used.
how does insulin help maintain homeostasis?
what functions to proteins have in the body?
what are the differences between sex cells and somatic (body) cells?

Explanation:

The questions are about biological structures, functions, and processes (DNA/RNA, oxygen transport, insulin, proteins, cell types), so the subfield is Biology (Natural Science).

Answer:

Biology (under Natural Science)