Question

A scientist observes that a cell has an RNA polymerase deficiency that prevents it from making proteins. Describe three additional observations that would together support the conclusion that a defect in RNA polymerase I activity, and not problems with the other polymerases, causes the defect.

a) The absence of mRNA, tRNA, and rRNA in the cell.
b) Reduced levels of mRNA and rRNA but normal tRNA levels.
c) Accumulation of untranslated mRNA and rRNA fragments.
d) Increased transcription of non-coding DNA sequences.

Answer 1

To support the conclusion that RNA polymerase I is deficient, observations should include reduced rRNA levels, normal tRNA levels, and altered mRNA levels, indicating a specific failure in ribosomal RNA transcription and potential indirect effects on other transcription processes.

Step-by-step explanation:

To conclude that a deficiency in RNA polymerase I activity is responsible for a cell's inability to make proteins, three observations supporting this would include:

Together, these observations would suggest a specific impairment in RNA polymerase I, as difficulties with the other polymerases would result in different patterns of RNA abundance and cell dysfunction.