How can a mutation in non-coding DNA change the activity of a cell?
A - OCR Gateway - GCSE Biology - Question 12 - 2020 - Paper 4
Question 12
How can a mutation in non-coding DNA change the activity of a cell?
A. It can change the amino acid sequence in a protein.
B. The base sequence of mRNA may be alte... show full transcript
Worked Solution & Example Answer:How can a mutation in non-coding DNA change the activity of a cell?
A - OCR Gateway - GCSE Biology - Question 12 - 2020 - Paper 4
Step 1
A. It can change the amino acid sequence in a protein.
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Answer
This statement is incorrect. Non-coding DNA does not directly code for proteins; thus, mutations here generally do not alter the amino acid sequence of proteins.
Step 2
B. The base sequence of mRNA may be altered.
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Answer
This might seem plausible, but mutations in non-coding regions usually do not affect the coding sequence directly—it is more likely that they influence regulatory elements.
Step 3
C. The shape of a protein may be changed.
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Answer
This is also not directly applicable, as the shape of a protein is determined by the amino acid sequence coded by the gene. Non-coding mutations do not change the shape of a protein unless they affect protein synthesis indirectly.
Step 4
D. Transcription of mRNA may be stopped.
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Answer
This statement is correct. Mutations in non-coding DNA can affect regulatory regions, which may lead to the stopping of transcription of mRNA, thereby altering the activity of the cell.
