soppose the DNA sequence GCTATATCG was changed to GCGATATCG.?

Question

how would the products of transcription and translation be affected?

Answer 1

First, translate the DNA sequence to an RNA sequence. Then get out your table of codons and check for stop codons in each sequence. If there are none, then transcription should be unaffected. Then look up each codon in turn to determine the amino acids coded for, and see if translation of each sequence gives the same or different A.A. sequences. (my suspish is that the T to G transformation in position 3 will result in an A.A. substitution...think about H bonding between the different classes of bases; purines vs pyrimidines)

Answer 2

Assuming that GCT was the beginning of the codon and that this is the sense sequence, GCU and GCG both code for alanine. If this is the nonsense sequence then CGC and CGU both code for Arginine, so it wouldn't make a difference either way.