4. chargaff's research had shown that there are four monomers in dna, in which two are always present in equal
amounts and the other two are always in equal amounts. we know that these monomers are the
of dna.

The monomers of DNA are individual nucleotides: cytosine,  guanine, adenine, and thiamine,  (A, T, C, G, respectively). Since DNA is a double-stranded molecule, each nucleotide has a match that chemically interacts with it to form nucleotide pairs

Explanation:

it enhances antibody production by t cells of the adaptive immune system.

hope i'm right

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