Question

A section of DNA is transcribed to produce a strand of mRNA. The original DNA has the following sequence of nitrogen bases:

ATG GCC CAA TCG TGA

Due to a point mutation, transcription results in the mRNA sequence of:
UAC CGG GUU AGU ACU

Transcription in this case will result in
A) a mutated protein that is potentially harmful.
B) the correct sequence of amino acids in the synthesized protein.
C) a situation where protein synthesis does not "stop" translating.
D) the incorrect sequence of amino acids in the synthesized protein.

Answer 1

The correct answer is B.) The correct sequence of amino acids in the synthesized protein.

Answer 2

In the mentioned case, transcription will result in B) the correct sequence of amino acids in the synthesized protein. According to the complementary rule, in the RNA, base complements are A-U (adenine - uracil) and G-C (guanine - cytosine). So, during the transcription of the following sequence of DNA "ATG GCC CAA TCG TGA", the correct sequence of RNA should be "UAC CGG GUU AGC ACU". As can be seen in the mutated sequence, the 4th codon is AGU instead of AGC. The effect the change will have on the synthesized protein will depend on the change in amino acid sequence. Since both AGU and AGC codons are for amino acid Serine. So, there will be no change in the sequence of amino acids in the synthesized protein.