TPR FL7 #12 about an exon

[Gauss44]

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A frameshift mutation involving insertion of one base pair in an exon may result in:

1. a protein product of lower molecular weight

2. loss of meiotic recombination of a gene

3. premature termination by RNA polymerase II

Why is the answer 1. only?

Me: Because #3 would create the problem (of the insertion) and not be stopped by it. #2 has little or nothing to do with transcription. And 1. doesn't really make sense, but it's the only answer left.

What's your reasoning? Do you agree with my above guess?

 

[Jepstein30]

A frameshift mutation involving insertion of one base pair in an exon may result in:

1. a protein product of lower molecular weight

2. loss of meiotic recombination of a gene

3. premature termination by RNA polymerase II

Why is the answer 1. only?

Me: Because #3 would create the problem (of the insertion) and not be stopped by it. #2 has little or nothing to do with transcription. And 1. doesn't really make sense, but it's the only answer left.

What's your reasoning? Do you agree with my above guess?

#1: frameshift mutation could lead to a nonsense mutation where the resulting translation is cut off early due to a termination codon
#2: as you said.. it has nothing to do with transcription/translation and is solely a DNA replication event.
#3: RNA Polymerase II is involved in transcription.. it generates the primary transcript so it is upstream from a frameshift mutation.

seems like you're spot on here..

 

[FeinMS]

When does frameshift mutation occur? At what level can a base inserted/deleted (DNA/pre-mRNA/mRNA, etc)? I was thinking that inserted/deleted base may create a transcription termination factor.

 

[Jepstein30]

When does frameshift mutation occur? At what level can a base inserted/deleted (DNA/pre-mRNA/mRNA, etc)? I was thinking that inserted/deleted base may create a transcription termination factor.

well, this specific frameshift mutation clearly says it occurs at the exon-level. Otherwise, you would have a valid point.