Question

1. there are 20 different amino acids and there are 64 mrna codons.

describe the connection between amino acids and codons.

• each codon sequence codes for multiple amino acids.
• each amino acid is only coded for by one codon sequence.
• an amino acid can be coded for by more than one codon sequence.

Explanation:

In the genetic code, a codon (a sequence of 3 mRNA nucleotides) codes for an amino acid. There are 64 codons and 20 amino acids. A single codon codes for only one amino acid (so the first option is wrong as a codon doesn't code for multiple amino acids). However, since there are more codons than amino acids, most amino acids are encoded by more than one codon (this is called degeneracy of the genetic code). So the third option is correct because an amino acid can be coded for by more than one codon sequence, while the second option is wrong as an amino acid is not only coded by one codon.

Answer:

C. An amino acid can be coded for by more than one codon sequence.