Question

RNA processing a. removes the introns, leaving only the exons. b. is the same as transcription. c. is an event that occurs after RNA is transcribed. d. is the rejection of old, worn-out RNA. e. Both a and c are correct.

Short answer

The short answer is: Option e. Both a and c are correct. RNA processing removes the introns, leaving only the exons (option a), and occurs after RNA is transcribed (option c).

Step-by-step solution

Information about RNA processing

RNA processing is a crucial step in eukaryotic gene expression where the precursor mRNA (pre-mRNA) is modified before it leaves the nucleus. The steps of RNA processing include addition of a 5' cap, removal of introns, and addition of a poly-A tail.

Option a

Removes the introns, leaving only the exons. This statement is true. During RNA processing, introns (non-coding regions) are removed from pre-mRNA through splicing, and only exons (coding regions) remain in the mature mRNA.

Option b

Is the same as transcription. This statement is incorrect. Transcription is the process of synthesizing RNA from a DNA template, while RNA processing involves modifying the synthesized RNA to ultimately form mature mRNA.

Option c

Is an event that occurs after RNA is transcribed. This statement is true. RNA processing takes place after the transcription of RNA (pre-mRNA) from DNA.

Option d

Is the rejection of old, worn-out RNA. This statement is incorrect. RNA processing is not related to rejecting old RNA. The cellular machinery degrades old or damaged RNA to maintain cell function and homeostasis.

Option e

Both a and c are correct. As mentioned earlier, options a (removes the introns, leaving only the exons) and c (is an event that occurs after RNA is transcribed) are both accurate descriptions of RNA processing. Therefore, option e is the correct answer.