ZOL2604
ASSIGNMENT 3 2025
UNIQUE NO.
DUE DATE: 2025
, Zoology II (Practical)
QUESTION 1 [10]
Practical applications of osmosis and diffusion in nature:
1. Water uptake by plant roots (osmosis)
o Process:
Plant root hair cells have a higher solute concentration (mainly mineral
ions) than the surrounding soil water. Water moves into the root hair cells
by osmosis through selectively permeable membranes.
o Application in nature:
This is essential for plant hydration, nutrient transport, and maintaining
turgor pressure, which supports the plant’s structure.
o Impact:
Without osmosis, plants would wilt and fail to photosynthesize effectively.
2. Gas exchange in the alveoli of lungs (diffusion)
o Process:
Oxygen diffuses from the alveoli (high O₂ concentration) into pulmonary
capillaries (low O₂ concentration), while carbon dioxide diffuses in the
opposite direction.
o Application in nature:
This diffusion process maintains respiration and is critical for aerobic
metabolism in animals, including humans.
o Impact:
Efficient gas exchange is essential for ATP production and survival.
3. (Extra example for completeness) Salt regulation in marine fish (osmosis)
o Process:
Marine fish live in hypertonic seawater. They lose water by osmosis and
must drink seawater, excreting excess salt via specialized gill cells.
o Application in nature:
Enables survival in saline environments.
ASSIGNMENT 3 2025
UNIQUE NO.
DUE DATE: 2025
, Zoology II (Practical)
QUESTION 1 [10]
Practical applications of osmosis and diffusion in nature:
1. Water uptake by plant roots (osmosis)
o Process:
Plant root hair cells have a higher solute concentration (mainly mineral
ions) than the surrounding soil water. Water moves into the root hair cells
by osmosis through selectively permeable membranes.
o Application in nature:
This is essential for plant hydration, nutrient transport, and maintaining
turgor pressure, which supports the plant’s structure.
o Impact:
Without osmosis, plants would wilt and fail to photosynthesize effectively.
2. Gas exchange in the alveoli of lungs (diffusion)
o Process:
Oxygen diffuses from the alveoli (high O₂ concentration) into pulmonary
capillaries (low O₂ concentration), while carbon dioxide diffuses in the
opposite direction.
o Application in nature:
This diffusion process maintains respiration and is critical for aerobic
metabolism in animals, including humans.
o Impact:
Efficient gas exchange is essential for ATP production and survival.
3. (Extra example for completeness) Salt regulation in marine fish (osmosis)
o Process:
Marine fish live in hypertonic seawater. They lose water by osmosis and
must drink seawater, excreting excess salt via specialized gill cells.
o Application in nature:
Enables survival in saline environments.
