Question

1. during a long-distance race, an athlete’s oxygen levels drop as they begin sprinting toward the finish line. muscle cells switch metabolic pathways and atp production decreases.

2a. which pathway becomes dominant when oxygen is low? (1 pt)

a aerobic respiration in the mitochondria
b photosynthesis in the chloroplast
c lactic acid fermentation in the muscle cells cytoplasm

Explanation:

To solve this, we analyze each option:

• Option A: Aerobic respiration requires oxygen, so it's not dominant when oxygen is low.
• Option B: Photosynthesis occurs in plants (chloroplasts), not in animal muscle cells.
• Option C: Lactic acid fermentation is an anaerobic process (no oxygen needed) that occurs in muscle cells when oxygen is scarce, making it the dominant pathway here.

Answer:

C. Lactic acid fermentation in the muscle cells cytoplasm