AP Biology / Unit 6: Gene Expression and Regulation
6.3 Transcription and RNA Processing
Notes
Transcription: RNA polymerase makes mRNA from the template strand, 5′ → 3′.
- In eukaryotes, the pre-mRNA gets a 5′ cap, a poly-A tail, and splicing removes introns and joins exons.
- Alternative splicing lets one gene make several proteins.
Practice
Introns are:
Exons are expressed.
The template strand is 3′-TACGGA-5′. The mRNA is:
Complementary with U.
Alternative splicing allows:
Different exon combinations.
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