Which substance do biochemists often search for in fossils to help better understand the evolutionary relationships of the organism that formed the fossil? A.
DNA

B.
iron

C.
ATP

D.
oxygen

   DNA the DNA identifys what animal was it male or female iron no thats a material ATP i have no clue whats that oxygen not even close it's DNA hope this helps:)

Explanation:

some fungi obtain their nutrients from a living host (plant or animal) and are called most biotrophic fungi have fairly narrow host ranges—they are specialized on a limited called rhizomorphs that allow the fungus to grow from one tree to another. ascospores are formed inside a sac-like structure called an ascus. so your answer is a