Diffusion & Osmosis (chpt. 13)

Question 1

Diffusion

Answer 1

The movement of molecules from an area of high concentration to an area of low concentration
Doesn’t need energy (passive)

Question 2

Osmosis

Answer 2

The movement of water from an area of high concentration to an area of low concentration across a selectively permeable membrane
No energy required

Question 3

Active transport

Answer 3

The movement of substances across a cell membrane against a concentration gradient using energy from respiration

Question 4

Osmoregulation

Answer 4

A system that consists of a contractile vacuole, this expels water

Question 5

Contractile vacuole

Answer 5

In amoeba, expels water

Question 6

Isotonic solution

Answer 6

Equal concentrations
Cell remains intact

Question 7

Hypotonic solution

Answer 7

Concentration of solutes is greater inside the cell than out of it
Cell may burst & die

Question 8

Hypertonic solution

Answer 8

Concentration of solutes is greater outside the cell than inside it
Cell may shrivel up & die

Question 9

Turgor pressure

Answer 9

Outward pressure of the cell contents against the cell wall of a plant

Question 10

What happens when a plant doesn’t get water

Answer 10

Wilt

Question 11

Plasmolysis

Answer 11

If placed in a hypertonic solution the cell cytoplasm shrinks

Question 12

Turgid cells

Answer 12

If placed in water the cell swells up

Question 13

2 examples of osmosis in food preservation

Answer 13

Sugar added to jam
Salt added to meat

Question 14

Why is osmosis used in food preservation

Answer 14

When microorganisms land on the food (e.g. jam) they lose water by osmosis and die
This extends the shelf life of the product

Question 15

Example of osmosis

Answer 15

Absorption of water by root hairs