2025 S3/4 CCKS Diffusion and Osmosis in Plants and Humans

Front

Define diffusion.

Back

The net movement of particles/substances from a higher concentration to a lower concentration down a concentration gradient

Front

What is the role of diffusion in nutrient uptake in plants?

Back

Diffusion allows nutrients to enter the root hair cell as they move from areas of higher concentration in the soil to lower concentration in the plant roots.

Front

How does diffusion facilitate gaseous exchange in humans?

Back

Diffusion allows oxygen to move from the alveoli in the lungs (high concentration) into the blood (low concentration)

Carbon dioxide moves from the blood (high concentration) into the alveoli (low concentration) via diffusion.

Front

Define osmosis.

Back

Osmosis is the net movement of water molecules from higher water potential to lower water potential through a partially permeable membrane.

Front

What are the effects of osmosis on plant tissues?

Back

Osmosis can cause plant cells to become turgid (swollen) when water enters, or plasmolysed (shrunken) when water exits, affecting the plant's structure and function.

Front

What are the effects of osmosis on animal tissues?

Back

In animal tissues, osmosis can lead to cell swelling/ bursting if water enters the cell or cell shrinkage (crenation) if water leaves the cell.

This is because they lack a cell wall.