The table below shows the daily water gain and loss for an individual under normal, resting conditions. Under these conditions, the volume of water taken in by the body is equal to the volume of water lost from the body.
| Method of water gain | Volume (cm3\text{cm}^3cm3) | Method of water loss | Volume (cm3\text{cm}^3cm3) |
|---|---|---|---|
| Food | 450 | Urine | 1400 |
| Drink | 1600 | Skin | 550 |
| Metabolism | 350 | Breathing | 320 |
| Faeces | xxx |
Calculate the volume of water, xxx, lost in faeces in one day. Show your working.
Which metabolic process produces water?
Explain why more water is lost through the skin when the person exercises (such as running a race).