Question

1. a dna strand has the sequence 5-actggaactagagc-3. what is the sequence of its complementary mrna?

Explanation:

Step1: Recall base - pairing rules

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

Step2: Determine the complementary mRNA sequence

Given DNA sequence 5'-ACTGGAACTAGAGC-3'.
The complementary mRNA sequence is 3'-UGACCUUGAUCUCG-5'. Reading from 5' to 3' (standard way for mRNA), it is 5'-CGAGAUUCAGGUCA-3'.

Answer:

5'-CGAGAUUCAGGUCA-3'