Question

A) The amino acid serine is coded by the mRNA codon AGU. What is the base sequence of
the DNA gene that originally produced this mRNA codon? (1 point)
TCA
UCA
TCC
AGU

Answer 1

To determine the base sequence of the DNA gene that codes for the mRNA codon AGU, we need to consider the relationships between DNA, mRNA, and codons.

1. The DNA sequence is complementary to the mRNA sequence.
2. The mRNA codon AGU corresponds to the template strand of DNA.

Given that the mRNA codon AGU has the following base pairs:
- A (adenine) pairs with T (thymine) in DNA
- G (guanine) pairs with C (cytosine)
- U (uracil) in mRNA corresponds to A (adenine) in DNA

Therefore, the complementary DNA sequence would be:

- A in mRNA corresponds to T in DNA
- G in mRNA corresponds to C in DNA
- U in mRNA corresponds to A in DNA

Thus, the DNA sequence that produces the mRNA codon AGU is **TCA**.

So, the answer is:
**TCA**.