Question

a gene has the sequence atcgattg. what is the sequence of the complementary rna?
uagcuaac
caaucgau
atcgattg
gttagcta
tacgtaac

Explanation:

Step1: Recall base - pairing rules

In transcription from DNA to RNA, A (adenine) in DNA pairs with U (uracil) in RNA, T (thymine) in DNA pairs with A (adenine) in RNA, C (cytosine) in DNA pairs with G (guanine) in RNA, and G (guanine) in DNA pairs with C (cytosine) in RNA.

Step2: Find the complementary RNA sequence

The DNA sequence is ATCGATTG.
For A in DNA, it's U in RNA; for T in DNA, it's A in RNA; for C in DNA, it's G in RNA; for G in DNA, it's C in RNA.
The complementary RNA sequence is UAGCUAAC.

Answer:

A. UAGCUAAC