[Campbell Biology P.395] Based on the provided text and Figure 17.13, which statement accura... | Practice Question

Based on the provided text and Figure 17.13, which statement accurately describes the role of the spliceosome in pre-mRNA processing?

  • A: The spliceosome is a complex of proteins and DNA that unwinds the pre-mRNA for transcription.
  • B: The spliceosome adds a poly-A tail to the pre-mRNA, preparing it for nuclear export.
  • C: The spliceosome, composed of proteins and small RNAs, removes introns and joins exons to form a continuous mRNA.
  • D: The spliceosome synthesizes new introns to be inserted into the mRNA molecule.

Explanation

The text explicitly states: 'The removal of introns is accomplished by a large complex made of proteins and small RNAs called a spliceosome.' It further notes that 'The spliceosome joins together the two exons that flanked the intron.' Figure 17.13 visually confirms this process.