What prokaryotic adaptation occurred during the oxygen revolution and opened up the possibility for energy-demanding multicellular life-forms?

• A. Electron transport systems
• B. Anaerobic fermentation
• C. Photosynthesis
• D. Emergence of obligate anaerobes
• E. Cellular respiration

Answer: (E)

Verified step by step guidance

1. Understand the context of the oxygen revolution, which refers to the Great Oxidation Event when oxygen levels in Earth's atmosphere significantly increased due to photosynthetic organisms.
2. Recognize that the increase in atmospheric oxygen allowed for the evolution of aerobic respiration, a more efficient way to produce ATP compared to anaerobic processes.
3. Identify that electron transport systems are a key component of cellular respiration, which uses oxygen to produce ATP through oxidative phosphorylation.
4. Acknowledge that the development of cellular respiration allowed organisms to extract more energy from glucose, supporting more complex and energy-demanding life forms.
5. Conclude that the adaptation of cellular respiration during the oxygen revolution was crucial for the evolution of multicellular organisms, as it provided the necessary energy to sustain complex biological processes.