nitrogen, oxygen, carbon dioxide, water vapour and other gases.
25
It is the most abundant type of gas in the air. About 78% of air is made up of it.
nitrogen
15
The type of gas needed by living things such as animals to stay alive.
oxygen
15
The carbon dioxide given out by the animals is used up by the ____________.
plants
15
How do humans get oxygen?
breathing
15
__________________ is the process by which air enters and leaves our body.
Breathing
15
What happens to our breathing rate when we exercise?
faster, increase
15
In the lungs, the air tubes branch into tiny tubes that end in air sacs. The air sacs are surrounded by blood vessels. What important process takes place in the air sacs?
gas exchange
15
3 main parts of our respiratory system
nose, windpipe and lungs
15
The _________ in the nostrils remove dust from the air we breathe in.
