Question

Which of the following represents a DNA mutation in the template strand that would convert serine to cysteine? (CODON TABLE)

a) 5-GCT-3 to 5-GCA-3
b) 5-AGC-3 to 5-TGC-3
c) 5-AGC-3 to 5-UGC-3
d) 5-AGU-3 to 5-UGU-3
e) 5-TCG-3 to 5-TCC-3

Answer 1

Option c) 5-AGC-3 to 5-UGC-3 represents a DNA mutation in the template strand that converts serine to cysteine.

Step-by-step explanation:

The correct answer is option c) 5-AGC-3 to 5-UGC-3. A change from AGC to UGC in the template DNA strand would result in a mutation that converts serine (AGC) to cysteine (UGC).

Remember that in DNA, Adenine (A) pairs with Thymine (T), and Guanine (G) pairs with Cytosine (C). So, in the complementary DNA sequence, the change from T to U represents the corresponding change from A to G in the mRNA sequence.

By transcribing the complementary DNA sequence 5'-TACGACTGACTAGCTA-3' into mRNA and translating it using the codon table, the resulting amino acid sequence is Methionine (start codon)-Asparagine-Leucine-Histidine (stop codon), which represents the peptide encoded by the mutated mRNA sequence.