Catabolite activator protein (CAP) only binds and activates the lac operon strongly when
- A
Glucose is high (cAMP rises, binds CAP, activating lac transcription)
- B
Lactose is absent (cAMP falls, binds CAP, repressing lac transcription)
- C
Bacteria are dividing (cAMP rises, binds CAP, activating lac transcription)
- Dcheck_circle
Glucose is low (cAMP rises, binds CAP, activating lac transcription)
Explanation
Low glucose → high cAMP → CAP-cAMP binds and recruits RNA pol; high glucose → low cAMP → CAP can't activate (catabolite repression of lac).