Question

1. how many unique possible combinations of nucleotide bases are there to make the amino - acids needed by protein synthesis? 20 64 60 24

Explanation:

Step1: Recall genetic code concept

In the genetic code, there are 4 nucleotide bases (adenine - A, thymine - T, guanine - G, cytosine - C in DNA; uracil - U replaces T in RNA). Codons are triplets of nucleotides that code for amino - acids.

Step2: Calculate number of combinations

The number of possible combinations of 4 bases taken 3 at a time is calculated using the formula for permutations with repetition. Since each position in the codon can have 4 choices, the total number of combinations is $4\times4\times4=4^{3}=64$.

Answer:

64