▶️ Answer/Explanation
Oxygen moves from an area of higher concentration in the soil air spaces into the root hair cell, where its concentration is lower, by the passive physical process of diffusion. Osmosis specifically refers to the movement of water molecules across a semipermeable membrane. Respiration is a chemical process that uses oxygen, but it is not the mechanism of entry. Ventilation refers to bulk airflow in animals, not gas entry into plant cells.
✅ Answer: (A) diffusion
✅ Answer: (A) diffusion
▶️ Answer/Explanation
In human respiration, carbon dioxide is the primary gaseous waste product generated in cells. For diffusion to occur from the blood vessel into the alveolus, there must be a concentration gradient where the concentration is high in the blood and low in the alveolar air space. This allows the gas to move naturally down its gradient to be exhaled. Oxygen is a reactant, not a product, of aerobic respiration, so options (C) and (D) are incorrect based on the question’s criteria.
✅ Answer: (B)
✅ Answer: (B)
▶️ Answer/Explanation
Detailed solution
The correct answer is D.
Reasoning:
Diffusion is the net movement of particles from an area of higher concentration to an area of lower concentration. Several factors affect the rate of this passive process:
- Temperature (Option D): Increasing the temperature increases the kinetic energy of the oxygen molecules. This causes them to move more rapidly and collide more frequently, leading to a faster rate of diffusion into the cell.