Answered

Codons Found in Messenger RNA

\begin{tabular}{|c|c|c|c|c|c|}
\hline \multicolumn{6}{|c|}{ Second Base } \\
\hline First Base & U & C & A & G & Third Base \\
\hline \multirow{4}{}{ U } & Phe & Ser & Tyr & Cys & U \\
& Phe & Ser & Tyr & Cys & C \\
& Leu & Ser & Stop & Stop & A \\
& Leu & Ser & Stop & Trp & G \\
\hline \multirow{4}{}{ C } & Leu & Pro & His & Arg & U \\
& Leu & Pro & His & Arg & C \\
& Leu & Pro & Gin & Arg & A \\
& Leu & Pro & Gin & Arg & G \\
\hline & Ile & Thr & Asn & Ser & U \\
\hline & lle & Thr & Asn & Ser & C \\
& lle & Thr & Lys & Arg & A \\
\hline & Met(Start) & Thr & Lys & Arg & G \\
\hline & Val & Ala & Asp & Gly & U \\
\hline & Val & Ala & Asp & Gly & C \\
\hline & Val & Ala & Glu & Gly & A \\
\hline
\end{tabular}

Using the information from the table, what sequence of nucleotides in the template strand of DNA could code for the polypeptide sequence Phe-Ser-Gin?

A. UUC-UCU-CAA
B. AAG-AGA-GTT
C. TTC-TCT-CAA
D. AAG-AGA-GUU



Answer :

GinnyAnswer
To determine the sequence of nucleotides in the template strand of DNA that codes for the polypeptide sequence Phe-Ser-Gin, follow these steps:

1. Identify the Codons: We know that the peptide sequence Phe-Ser-Gin corresponds to the mRNA codons UUC, UCU, and CAA. This is directly from the problem statement.

2. Determine the Complementary DNA Sequence:
- In mRNA, the bases pair with their complementary bases during transcription to form the template DNA strand:
- Adenine (A) pairs with Thymine (T) in DNA.
- Uracil (U) in RNA pairs with Adenine (A) in DNA.
- Cytosine (C) pairs with Guanine (G).
- Guanine (G) pairs with Cytosine (C).

Using these base pairing rules, convert each mRNA codon to its corresponding DNA template sequence:
- UUC (mRNA) -> AAG (DNA)
- UCU (mRNA) -> AGA (DNA)
- CAA (mRNA) -> GTT (DNA)

3. Combine the Template DNA Sequences: Now put these individual DNA sequences together to form the complete template strand sequence:
- AAG-AGA-GTT

So, the sequence of nucleotides in the template strand of DNA that could code for the polypeptide sequence Phe-Ser-Gin is:

AAG-AGA-GTT

Other Questions