The figure shows a general schema of a genomic region coding for a protein G. The striped box shows the promoter. Transcription starts at the line marked "100".
A. When this gene is transcribed (pre-mRNA), how long (in number of nucleotides) is the transcript?
B. Two different mature transcripts (mRNAs) are produced from this gene; one is approximately 3000 nucleotides long, the other is about 4000 nucleotides long. Explain how two different transcripts can be produced from this gene.
C. Assume that each of the above transcripts (mRNAs) is translated. Given your answers in the part B, what is the approximate size of the two proteins?
Assume gene G was mutated such that the base pair found at position 200 was changed from an A/T to a G/C. Transcription and translation of the altered gene G still occurs.
D. Would the first transcript be the same length, shorter or longer than the first transcript produced from the wild type gene G? Give all possible answers and explain your thinking.
E. Would the protein produced be the same length, shorter or longer than the protein produced from the wild type gene G? Give all possible answers and explain your thinking.
Now assume gene G was mutated such that only the base pair found at position 4100 was changed from a C/G to an A/T. Transcription and translation of gene G still occur.
F. Would the first transcript be the same length, shorter or longer than the first transcript produced from the wild type gene G? Give all possible answers and explain your thinking.