To determine which sequence shows a substitution mutation compared to the original DNA sequence, we need to identify a position where a single nucleotide in the original sequence is replaced with a different nucleotide in one of the provided options.
The original sequence is:
C G T T A C T G C A A T
G C A A T G A C G T T A
Now, let's compare this sequence to each of the provided options for substitutions:
-
First Option:
C G T G A C T G C A A T G C A C T G A C G T T A- DNA mutations:
- First line: T changed to G.
- Second line: A changed to C.
- Both lines show substitutions. This option contains substitution mutations.
- DNA mutations:
-
Second Option:
C G T A C T G C A A T G C A T G A C G T T A- DNA mutations:
- First line: T changed to A.
- Second line: A changed to T.
- Both lines show substitutions. This option contains substitution mutations.
- DNA mutations:
-
Third Option:
C G T T A C T G C A A T G C A A T G A C G T T A- No mutations: The sequences are identical.
- This option does not contain any mutations.
-
Fourth Option:
C G T C T A C T G C A A T G C A G A T G A C G T T A- DNA mutations:
- First line: T changed to C (first line).
- Second line: A changed to G (second line).
- Both lines show substitutions. This option contains substitution mutations.
- DNA mutations:
Conclusion
All options except the third contain substitution mutations. However, if the question asks for just one correct answer showing a substitution mutation, any of the first, second, or fourth options would be correct.
If we must choose a singular answer and the order of preference matters, the first option shows substitutions at clear, simple and different positions, making it a very good example.
Most Suitable Answer: The first option.
1 answer