The four nucleotides found in human DNA (G, A, T, and C) combine in groups of three to create potentially 64 different amino acids, but only 20 amino acids, one start codon, and three stop codons are used to construct proteins. Why is this so?
a. 64 amino acids are initially produced, but 42 of them are unstable and degrade immediately.
b. 64 amino acids are produced, but the body only integrates 42 of them into proteins.
c. Different nucleotide combinations code for the same amino acid.
d. Many amino acids are not considered complete until they bind with a second amino acid.