Do Introns or Exons Leave the Nucleus?

Introns: Sections of mRNA not needed to produce a protein. These are cut out of the mRNA and kept in the nucleus. Exons: Sections of mRNA containing the code to synthesize a protein. These are exported from the nucleus and proceed to the ribosome where they are used to synthesize the protein.

Do exons stay in the nucleus?

Exons are coding sections of an RNA transcript, or the DNA encoding it, that are translated into protein. ... These pre-mRNA molecules go through a modification process in the nucleus called splicing during which the noncoding introns are cut out and only the coding exons remain.

Do introns leave the nucleus while exons are spliced and remain in the nucleus?

Both introns and exons are transcribed, but the RNA transcribed from introns does not leave the nucleus. ... Exons are cut out of the primary transcript, and the introns are spliced together. Introns are cut out of the primary transcript and spliced together at the end of the transcript.