Question

Why both strand of dna not use during transcription

Answer 1

If both the strands of DNA are copied, they would code for RNA molecule with different sequences and in turn when they code for proteins, the sequence of amino acids in the proteins would be different.

If RNA molecules are produced simultaneously , they would be complementary to each other and hence form double stranded RNA due to complementary base pairing. Due to the above reasons, both the starnds of DNA are not copied during DNA replication.