Osmosis & Diffusion

Question 1

Diffusion

Answer 1

Passive movement from an area of high concentration to low concentration

Question 2

Osmosis

Answer 2

Passive movement of water through a selectively permeable membrane from an area of high concentration to low concentration

Question 3

Fully Permeable membrane

Answer 3

Any substance can pass through freely

Question 4

Impermeable membrane

Answer 4

No substance can pass through

Question 5

Selectively Permeable membrane

Answer 5

Controlled entry and exit of molecules

Question 6

Semi-Permeable

Answer 6

Some molecules can pass through depending on size

Question 7

Turgor

Answer 7

The outward pressure of the cytoplasm and vacuole against the cell wall of a plant

Question 8

Diffusion in lungs

Answer 8

• Oxygen diffuses from the atmosphere into the leaf
• Oxygen diffuses from the leaf into the atmosphere
• Water vapour diffuses from the lef into the atmosphere during transpiration

Question 9

Osmosis in animal cells

Answer 9

In low water concentration:
- More water moves into cell & bursts
- Hypotonic cell - a cell where the water is moved in by osmosis

In high water concentration:
- Water moves out of cell by osmosis
- crenation - the cell shrivels

Question 10

Osmosis in plant cells

Answer 10

In high water concentration:
- Water moves into cell & cell wall stops it from bursting
- Water causes turgor pressure giving plant strength and support
(opens stoma, said to be turgid)

In low water concentration:
- Water moves out of cell
- Causes plasmolysis (cell shrinks)
(Cell is said to be flaccid)

Question 11

Osmosis in Amoeba

Answer 11

• Can store or expel water using contractile vacuole (osmoregulation)
• Water can rush in or out of amoeba cells (depends on environment)

Question 12

Food preservation

Answer 12

• Food in a high sugar or salt environment is preserved by osmosis
• Microorganisms lose water and die/can’t reproduce