Question

A sequence of how many nucleotides in messenger RNA makes a codon for an amino acid

• A. Four
• B. One
• C. Two
• D. Three

Answer 1

The Correct Option is D

The question asks about the number of nucleotides in a messenger RNA (mRNA) sequence that constitute a codon. A codon is a sequence found in mRNA that corresponds to a specific amino acid.

In the genetic code, each codon consists of three nucleotides. This is often referred to as a triplet. For example, the mRNA codon "AUG" codes for the amino acid Methionine. The reason for having three nucleotides in a codon is based on the need to code for all 20 amino acids using four possible nucleotides (adenine, uracil, cytosine, and guanine).

The possible number of codons can be calculated by raising the number of nucleotide types (4) to the power of the length of the codon (3):

4^3 = 64

This results in 64 possible codons, which provides enough combinations to code for all amino acids, including stop signals that indicate the end of protein synthesis.

Therefore, the correct answer is Three, as each codon in mRNA consists of three nucleotides.