During a deficiency of oxygen in human tissues, pyruvic acid is converted into lactic acid in the cytoplasm.
Explanation: When oxygen is scarce, cells cannot undergo aerobic respiration (which uses oxygen in the mitochondria) and instead resort to anaerobic respiration, where pyruvate is converted to lactic acid in the cytoplasm.
Why other options are incorrect:
Chloroplast:
Chloroplasts are organelles specific to plant cells and are involved in photosynthesis, not lactic acid production.
Mitochondria:
Mitochondria are the “powerhouse” of the cell and are where most ATP production occurs during aerobic respiration. However, when oxygen is limited, this process cannot happen, and pyruvate is diverted to the cytoplasm for lactic acid production.
Golgi body:
The Golgi body is involved in packaging and distributing proteins and other materials within the cell. It has no role in lactic acid production.