Suppose that the coding region of a gene contains 1,800 base pairs, with 570 in exon 1, with 420 in exon 2, and with 810 in exon 3 (not counting the stop codon).The protein translated from this gene will consist of _______ amino acids.
A) 190
B) 597
C) 600
D) 819
E) 1,800

Question

Quizplus · Accepted Answer

To determine the number of amino acids in the protein, we need to consider the number of codons (three-nucleotide sequences) that will be translated from each exon, as well as the stop codon at the end. 
Exon 1 has 570 base pairs, which represents 190 codons. 
Exon 2 has 420 base pairs, which represents 140 codons. 
Exon 3 has 810 base pairs, which represents 270 codons. 
Adding up the codons from each exon gives us a total of 600 codons, but we must subtract one for the stop codon, giving a final count of 599 codons. Each codon codes for one amino acid, so the protein translated from this gene will consist of 599 amino acids.

Suppose That the Coding Region of a Gene Contains 1,800