3.3 - How development is controlled Flashcards
1
Q
What is meant by gene expression?
A
whether genes are switched on or off
2
Q
Before transcription can begin, what stimulates the gene?
A
transcriptional factors
3
Q
How does a transcriptional factor stimulate the gene?
A
forms a pre-initation complex with RNA polymerase
4
Q
Which molecules switch off the transcriptional factors?
A
repressor molecules
5
Q
How do repressor molecules switch off transcriptional factors?
A
repressors bind to transcriptional factors, preventing it from attaching to DNA.
without the transcriptional factor, the DNA cannot be transcribed
6
Q
A
7
Q
How does DNA methylation influence which genes are transcribed?
A
methyl groups attach to DNA which stops RNA polymerase binding and thus prevents transcription to mRNA
8
Q
A
