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A genetic disease in which there's a complete loss of enzyme activity. A northern blot was done on tissue sample and revealed normal enzyme amount. What could explain the genetic defect?
-Gene mutation
-Splicing mutation
-Promotor mutation
-Transcriptional defect
-Nonsense mutation
-Silent mutation
-Missense mutation
-Postranslational defect
 

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It's not even missense mutation because mis sense mutation just causes an amino acid replacement and the enzyme may be still functional.
The correct answer is nonsense mutation which causes a non functional enzyme.
 

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I don't get it, isn't Northern blot test supposed to detect RNA sequence too. Or just the length.
:eek:
Blotting will not occur if the probe is not complementary to the mRNA sequence. So yes it detects correct sequence mRNA strands!!
I think the question is designed wrong. They should say normal amount of mRNA and they should not say normal Northern blot.
I think I've seen a similar question in Kaplan Qbank that had a similar theme and concept and I think they mentioned just mRNA they did not say Northern blot.
 
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