Can energy be harvested by cells from glucose without the presence of oxygen, and if so, what process is primarily responsible for this?

• A. No, oxygen is always required
• B. Yes, through fermentation
• C. Yes, through aerobic respiration
• D. Yes, through photosynthesis

Answer: (B)

Verified step by step guidance

1. Understand that cells can harvest energy from glucose through different metabolic pathways, depending on the presence or absence of oxygen.
2. Recognize that in the absence of oxygen, cells can still produce energy through a process called fermentation.
3. Fermentation is an anaerobic process, meaning it does not require oxygen, and it allows cells to convert glucose into energy.
4. During fermentation, glucose is partially broken down, and the end products can include lactic acid or ethanol, depending on the type of cell.
5. This process is less efficient than aerobic respiration, as it produces less ATP (adenosine triphosphate), but it allows cells to survive and generate energy when oxygen is not available.