This table shows the codons found in messenger RNA (attached). Using this information, what sequence of nucleotides in the template strand of DNA could code for the polypeptide sequence Val-His-Thr? A. GUA-CAU-ACC
B. GTA-CAT-ACC
C. CAT-GTA-TGG
D. CAU-GUA-UGG

Please explain, I'm very confused about this topic and I want to learn about it. No false answers or you will immediately be reported. Thanks in advance!

A

Explanation:

The correct answer would be option A - GUA-CAU-ACC

Looking at the table of codons, for the amino acid Val, the first base (which is on the 1st column in the 6th row) is G while the second base (2nd column, 2nd row) is U. The third column can be any of U, C, A, or G (6th column, 4th row). Hence, GUA is plausible

For the amino acid His, the first base is C (1st column, 2nd row), the second is A (4th column, 4th row) while the last could be any of the 4 bases. Hence, CAU is plausible.

For the amino acid Thr, the first base is A (first column, 5th row), the second is C (3rd column, 2nd row) while the 3rth could be any of the 4 nucleotide bases. Hence, ACC is plausible.

Therefore, the correct sequence of nucleotides for Val-His_Thr would be GUA-CAU-ACC