Gas And Solute Exchange Flashcards
Name 3 ways substances move?
Substances move by diffusion, osmosis and active transport.
What needs to get into plant cells in order for photosynthesis to happen?
Carbon dioxide and water need to
What has to enter cells in order for respiration to happen?
Glucose and oxygen both have to get inside the cells for respiration to happen.
Why do waste materials have to move out of plants?
So the organism can get rid of them.
Define diffusion?
Diffusion is the movement of particles from an area of high concentration to a low concentration.
True or false gases can diffuse in and out of cells through cell membranes?
True.
What do the exchange surfaces have to allow enough of to pass through them?
They have to allow enough necessary substances to pass through them.
Why are exchange surfaces adapted?
In order to maximise effectiveness.
Name 4 ways exchange surfaces are adapted and why this maximises effectiveness?
- They are thin - this is so substance only have a short distance to diffuse.
- They have a large surface area - this is so lots of substances can diffuse at once.
- In animals the exchange surface had lots of blood vessels - to get stuff into and out of the blood quickly.
- In animals there is gas exchange surfaces - this allows air to move in and out.
True or false exchanging substances gets more difficult the bigger and more complex the organism is?
True
Why does exchanging substances get more harder for bigger and more complex organisms?
Because the place where the substances are needed is further away from the exchange surface.
What does the structure of the leaf allow gases to do?
It allows them to diffuse in and out of cells.
Where does carbon dioxide diffuse?
Carbon dioxide diffuses into the air spaces within the leaf, then it diffuses into the cells where photosynthesis happens.
Where is the exchange surface found on a leaf?
Underneath of the leaf.
What is the underside of the leaf covered with?
Tiny holes called stomata which the carbon dioxide diffuses in through.
What diffuses out of the stomata?
Oxygen and water vapour diffuse out of the stomata?
What is the size of the stomata controlled by?
Guard cells.
What happens when the plant is losing water faster then it’s being replaced by the roots?
The guard cells close the stomata if too much water is being lost.
Why is closing the stomata helpful to the plant?
By closing the stomata it prevents water vapour diffusing out of the stomata. So this preserves water for the plant and stops the plant wilting.
Why does having a flattened shape make the exchange surface on a leaf more effective?
Because having a flattened shape increases the area of the exchange surface so more gases can diffuse into and out of the leaf.
Name two exchange surfaces in a plant?
The underneath of a leaf and the walls of cells inside the leaf.
What does the air spaces inside the leaf maximise?
The air spaces increase the area of the exchange surface so there’s more chance for carbon dioxide to get into cells.
True or false water vapour evaporates from the cells inside the leaf?
True.
How does the water vapour move from the inside the leaf into the air?
Once the water vapour has evaporated from the cells in the leaf then it escapes by diffusion because there’s a lot of it inside the leaf and less of it in the air outside.
Name 3 conditions where evaporation happens the quickest?
In hot, dry and windy conditions.
