A frameshift mutation occurs when nucleotides are added or deleted from the DNA sequence in a number that is not a multiple of three, thereby shifting the reading frame of the sequence.
Let's analyze each option for frameshift mutations due to deletion:
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ATG TTT GGC TAA
- Original: ATG AAG TTT GGC TAA has lost one nucleotide (the "A" from "AAG"). This causes a shift in the reading frame, so this is a frameshift mutation.
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ATG AAG TTG GCT AA
- Original: ATG AAG TTT GGC TAA has lost "T" from "TTT" (at position 4). This also shifts the reading frame, so this is a frameshift mutation as well.
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ATG AAG TTT GGC GCA TAA
- Original: This option does not indicate a deletion. Instead, it adds "GCA". Therefore, this is not a frameshift mutation due to deletion.
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ATG UAA GTT TGG CTA A
- This sequence isn't a simple deletion but includes a non-standard base ("U" for uracil), which would not typically be present in a DNA sequence. Thus, it doesn't represent a frameshift mutation due to deletion in the traditional sense.
So, among the options provided, both the first two ("ATG TTT GGC TAA" and "ATG AAG TTG GCT AA") reflect frameshift mutations due to deletion.
However, if you are looking for one specific answer and only one choice is allowed:
Choose ATG TTT GGC TAA (the first option) as it clearly represents a frameshift mutation due to a deletion.