If a specific gene code for a polypeptide is 120 amino acids long, approximately how many nucleotides long is the mRNA that codes for this polypeptide?

Question

a
360
b
40
c
30
d
480

Answer 1

To determine the length of the mRNA that codes for a polypeptide consisting of 120 amino acids, we need to consider that each amino acid is coded for by a sequence of three nucleotides (codons) in the mRNA.

Here's the calculation:

1. Each amino acid is encoded by 3 nucleotides.
2. Therefore, for 120 amino acids, the total number of nucleotides in the mRNA would be:

$$120\text{ amino acids}\times 3\text{ nucleotides/amino acid}=360\text{ nucleotides}$$

Thus, the mRNA that codes for this polypeptide is approximately 360 nucleotides long.

The correct answer is:

a) 360