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?
UCA
TCA
TCC
AGU
The base sequence of the DNA gene that originally produced the mRNA codon AGU is TCA.
To determine the base sequence of the DNA gene that produced the mRNA codon AGU, we need to find the complementary DNA sequence.
The mRNA codon AGU corresponds to the DNA codon UCA, since mRNA codons have the same sequence as the complementary DNA strand.
Therefore, the base sequence of the DNA gene that originally produced this mRNA codon is UCA.
To determine the base sequence of the DNA gene that originally produced the mRNA codon AGU, we need to perform the process of transcription, where the information from the DNA is converted into mRNA.
First, we need to know that the mRNA codons are complementary to the DNA codons. The DNA codon is transcribed to form a complementary mRNA codon using the following base pairing rules:
- Adenine (A) in DNA pairs with Uracil (U) in mRNA.
- Thymine (T) in DNA pairs with Adenine (A) in mRNA.
- Guanine (G) in DNA pairs with Cytosine (C) in mRNA.
- Cytosine (C) in DNA pairs with Guanine (G) in mRNA.
Given that the mRNA codon is AGU, we can determine the DNA codon by applying the base pairing rules:
mRNA codon: AGU
Complementary DNA codon:
- A in DNA pairs with U in mRNA, so it becomes T in DNA.
- G in DNA pairs with C in mRNA, so it remains the same.
- U in mRNA pairs with A in DNA, so it becomes T in DNA.
Therefore, the base sequence of the DNA gene that originally produced the mRNA codon AGU is TCA.