The synthesis of nucleotides requires several amino acids. Identify each amino acid as a precursor in the synthesis of purines, pyrimidines, both purines and pyrimidines, or neither purines nor pyrimidines.

answer///multiple alleles;

above statement is not a true statement about the open ocean because the open ocean has low levels of nutrients. most of the photosynthetic activity on earth occurs in the open ocean within the photic zone. organisms in the deep ocean are exposed to frigid temperatures and total darkness but it does not begin at the low-tide mark.