IB Biology HL D2.2.11 Hl External Factors Questions
Analyse how an external lactose signal changes repressor binding, promoter access and enzyme production in IB Biology HL D2.2.11.
- Syllabus
- First assessment 2025
- Course
- Biology HL
- Level
- HL
Analyse how an external lactose signal changes repressor binding, promoter access and enzyme production in IB Biology HL D2.2.11.
The diagram shows a nucleosome from the nucleus of a eukaryotic cell.
Explain the role of lactose in the expression of the gene for lactase production.
lactose binds to repressor protein;
repressor protein (with lactose bound) cannot block/bind to the promoter/Y;
RNA polymerase/X binds to the promotor/transcribes the gene;
lactase produced (if lactose present)/lactase production inhibited if lactose absent;