Which of the following structures contributes to dna's ability to function as a template for the production of new dna or mrna molecules? a. location of covalent bonds between the nitrogenous base b. orientation of deoxyribose sugar next to phosphate groups c. complementary base pairing between nitrogenous bases (a, t, c, g) d. presence of phosphate groups in the backbone of the molecule

c. Complementary base pairing between nitrogenous bases (A, T, C, G)

Explanation:

The sequence of nucleotide help to copy it and form a new DNA or mRNA.

what's the rest of the question

white blood cells or wbc s are mainly 2 types-

1.agranulocytes

2.granulocytes

the monocytes or macrophages of agranulocytes , dendritic cells which are accessory leucocytes, and b cells which is one type of lymphocytes   identify the antigens present on the pathogen's surface. these three cells are called antigen presenting cells(apc) which are phagocytes and destroy the antigens by secreting antitoxins. besides this leukocyte is always plays vital role in the immunity of the body.