Exchanging substances

Cards (9)

Why does gas exchange happen in the lungs?
To transfer oxygen to blood and remove carbon dioxide from it
Where does gas exchange happen in the lungs?
Alveoli
How are the alveoli specialised?
A large surface area, a moist lining for dissolving gases, very thin walls and a good blood supply
How does food absorb into the blood?
The small intestine is covered in villi
How are villi specialised?
They have a single layer of surface cells, a large surface area and a good blood supply to assist quick absorption
How does gas diffuse in and out of cells?
Carbon dioxide diffuses into the air spaces and then into the cells
How is a leaf adapted for gas exchange?
The underneath of the leaf is an exchange surface, oxygen and water vapour diffuse out of the stomata and the size of the stomata is controlled by guard cells
How are fish specialised for gas exchange?
They have gills which let the oxygen escape from the fish's body after it enters through the mouth
How are gills specialised?
They have a large surface area as they are made from gill filaments and each gill is covered in lamellae