Question

imagine you are studying the function of a gene in yeast cells called sir2. you want to reduce the expression of sir2 to see what happens if cells dont have it. recall that enhancers are regulatory sequences that bind activating transcription factors (activators) and silencers are regulatory sequences that bind to repressing transcription factors (repressors).
which genetic modifications could help you accomplish this? select all that apply.

• increasing the amount of activator proteins that can bind enhancers near sir2
• increasing the amount of repressor proteins that can bind silencers near sir2
• adding more enhancers near the sir2 gene
• changing the promoter sequence of the sir2 gene so that rna polymerase binds better
• adding more silencers near the sir2 gene

Explanation:

• To reduce \( SIR2 \) expression, we need to promote repression or inhibit activation.
• Increasing activators (first option) or enhancers (third option) or improving promoter - RNA polymerase binding (fourth option) would increase gene expression, so they are incorrect.
• Increasing repressor proteins that bind silencers (second option) and adding more silencers (fifth option) will increase repression, thus reducing \( SIR2 \) expression.

Answer:

B. Increasing the amount of repressor proteins that can bind silencers near \( SIR2 \)
E. Adding more silencers near the \( SIR2 \) gene