B4 - Diffusion and osmosis Flashcards
1
Q
What is diffusion?
A
Diffusion is the movement of gas from a high concentration to a low concentration.
2
Q
How are leaves adapted to increase the rate of diffusion?
A
- usually a large surface area
- specialist opening cells called stomata
- spaced out stomata
- gaps between spongy mesophyll
3
Q
What is a semi-permeable membrane?
A
A semi-permeable membrane allows the passage of small molecules but not large complex molecules.
4
Q
How can the rate of diffusion be increased?
A
- having a shorter distance to travel
- having a greater difference in concentration
- having a greater surface area for particles to enter or escape from
5
Q
What is osmosis?
A
Osmosis is the movement of water.
6
Q
What does turgid mean?
A
Turgid is when the cell becomes hard and rigid.
7
Q
What does flaccid mean?
A
Flaccid is when the cell becomes soft and floppy.
8
Q
What happens to an animal cell during osmosis and why?
A
- it will swell and burst when too much water enters
- it shrinks when too much water leaves
this is because it does not have a cell wall
9
Q
What does plasmolysed mean?
A
When a plant cell shrinks because it loses too much water.
