| Living things have to remove the harmful effects of waste products. |
|
Some of these waste products are: CARBON DIOXIDE NITROGEN WATER |
|
Animals, such as humans, cats, dogs, remove the harmful effects of the gas carbon dioxide by breathing out. They also breathe out water vapour. |
 |
|
To help them to grow and repair, cells of the body need nitrogen. As the cells wear out and new ones take their place, the nitrogen waste goes from them into the blood and must be removed.
|
 |
| The main organs which remove nitrogen waste from the body are the kidneys. |
 |
