In order to test the effects of a new drug, you isolate the messenger RNA molecules from both treated and untreated eukaryotic cells and separate them according to size using gel electrophoresis. In each lane of the gel, the shorter RNA molecules migrate more quickly through the gel and end up near the bottom of the gel while the longer RNAs migrate more slowly and remain near the top. The samples that were loaded into each of the four lanes are as follows: Lane 1: the primary RNA transcripts isolated from the nucleus of untreated cells
Lane 2: the primary RNA transcripts isolated from the nucleus of cells treated with the drug being tested
Lane 3: RNA isolated from the cytosol of untreated cells
Lane 4: RNA isolated from the cytosol of cells treated with the drug being tested
Which of the following conclusions is most likely to be CORRECT?
A)These results suggest that the drug inhibits post-translational processing of this gene.
B)These results suggest that the drug contains a protease that targets this gene product.
C)These results suggest that the drug digests DNA.
D)These results suggest that the drug affects RNA processing.
E)These results suggest that the drug inhibits DNA replication.

Question

In order to test the effects of a new drug, you isolate the messenger RNA molecules from both treated and untreated eukaryotic cells and separate them according to size using gel electrophoresis. In each lane of the gel, the shorter RNA molecules migrate more quickly through the gel and end up near the bottom of the gel while the longer RNAs migrate more slowly and remain near the top.  The samples that were loaded into each of the four lanes are as follows: Lane 1: the primary RNA transcripts isolated from the nucleus of untreated cells
Lane 2: the primary RNA transcripts isolated from the nucleus of cells treated with the drug being tested
Lane 3: RNA isolated from the cytosol of untreated cells
Lane 4: RNA isolated from the cytosol of cells treated with the drug being tested
Which of the following conclusions is most likely to be CORRECT?
A)These results suggest that the drug inhibits post-translational processing of this gene. 
B)These results suggest that the drug contains a protease that targets this gene product. 
C)These results suggest that the drug digests DNA. 
D)These results suggest that the drug affects RNA processing. 
E)These results suggest that the drug inhibits DNA replication.

Quizplus · Accepted Answer

The separation of the primary RNA transcripts in lanes 1 and 2 suggests that the drug may be affecting RNA processing, as the two samples would be expected to contain the same primary transcripts before any processing occurs. Additionally, the separation of the cytosolic RNAs in lanes 3 and 4 could provide further evidence of the drug's effect on RNA processing, as any differences in the size or abundance of the cytosolic RNAs would likely reflect alterations in the processing or stability of the mature RNAs.

In Order to Test the Effects of a New Drug