Question

a particular triplet of bases in the template strand of a coding sequence of dna is aaa. the anticodon on the trna that binds the corresponding mrna codon is ______. hint: think about which strand of dna (template strand or coding strand) is identical to mrna sequence...
a ttt
b uua
c uuu
d aaa

Explanation:

• DNA to mRNA transcription:
• The template strand of DNA is used to synthesize mRNA. In DNA - RNA base pairing, adenine (A) in DNA pairs with uracil (U) in RNA, thymine (T) in DNA pairs with adenine (A) in RNA, cytosine (C) in DNA pairs with guanine (G) in RNA, and guanine (G) in DNA pairs with cytosine (C) in RNA.
• Given the DNA template strand triplet \(AAA\), the corresponding mRNA codon is \(UUU\) (because \(A\) in DNA template pairs with \(U\) in mRNA).
• mRNA - tRNA base pairing:
• tRNA anticodon pairs with mRNA codon. The base - pairing rules for mRNA - tRNA are the same as for DNA - RNA (A - U, U - A, C - G, G - C).
• Since the mRNA codon is \(UUU\), the tRNA anticodon that binds to it is \(AAA\) (because \(U\) in mRNA pairs with \(A\) in tRNA).

Answer:

D. AAA