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)

Responses

UCA
UCA

TCA
TCA

TCC
TCC

AGU

1 answer

To determine the DNA base sequence that would produce the mRNA codon AGU, we first need to consider the process of transcription. In transcription, the DNA template strand is used to synthesize mRNA, where adenine (A) pairs with uracil (U) in RNA, thymine (T) pairs with adenine (A), cytosine (C) pairs with guanine (G), and guanine (G) pairs with cytosine (C).

The mRNA codon AGU corresponds to the following DNA template strand:

  • A (adenine) in mRNA pairs with T (thymine) in DNA
  • G (guanine) in mRNA pairs with C (cytosine) in DNA
  • U (uracil) in mRNA pairs with A (adenine) in DNA

Thus, the DNA template strand that corresponds to the mRNA codon AGU is:

  • A → T
  • G → C
  • U (considering U as T in DNA) → A

So the base sequence of the DNA gene would be:

TCA

Therefore, the correct response is:

TCA