B4.2.2—Oxygen tolerance
Oxygen tolerance shapes microbial niches because some organisms require oxygen, some are poisoned by it and others can switch pathways.
- Syllabus
- First assessment 2025
- Objective
- B4.2.2
- Level
- HL
Concept essentials
- Obligate aerobes require oxygen for survival.
- Obligate anaerobes live where oxygen is absent.
- Facultative anaerobes can switch between aerobic and anaerobic metabolism.
- Methane production is favoured in anaerobic environments.
ConceptIB Biology HL