AP BIOLOGY

LABORATORY REVIEW

MOLECULAR BIOLOGY

Question [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
How many codons are in this mRNA molecule?AUG UAA ACC GAG CCA UAG
A
18
B
6
C
1
D
5
Explanation: 

Detailed explanation-1: -The three-letter nature of codons means that the four nucleotides found in mRNA-A, U, G, and C-can produce a total of 64 different combinations. Of these 64 codons, 61 represent amino acids, and the remaining three represent stop signals, which trigger the end of protein synthesis.

Detailed explanation-2: -Three of these codons are stop codons: UAA, UAG, and UGA. The remaining 61 codons encode 20 amino acids. Out of these 61 codons, the codon AUG (which encodes the amino acid methionine) also serves as a the start signal (start codon) for translation initiation.

Detailed explanation-3: -This leads to a total of 10 codons in the mRNA sequence AUGGCAGUGCCA as AUG, UGG, GGC, GCA, CAG, AGU, GUG, UGC, GCC, CCA.

Detailed explanation-4: -AUG is the codon for methionine, and is also the start codon.

There is 1 question to complete.