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.

Short answer

The absence of functional ribosomes in the cell and the absence of RNA polymerase I protein indicate that RNA polymerase I deficiency or mutation causes defects in protein production.

Step-by-step solution

Step 1. Introduction

RNA Polymerase is a significant enzyme participating in transcription. It syntheses RNA by following the DNA strand.

Step 2. Explanation

To observe the RNA polymerase I deficiency causing defects in protein production scientists need to provide evidence that RNA polymerase II and III are functioning properly.

1. The presence of processed mRNA in cytoplasm and transcription of mRNA in the nucleus eliminates RNA polymerase II as a defect.
2. Isolation of snRNA and microRNA from the cells and the presence of tRNA in the cell eliminates RNA polymerase III as a defect.
3. The absence of functional ribosomes in the cell and the absence of RNA polymerase I protein indicate that RNA polymerase I deficiency or mutation causes defects in protein production.