If a person is to survive, the internal environment of their body must be controlled - Edexcel - GCSE Biology - Question 4 - 2012 - Paper 1

To find the difference:

1. Calculate the mean volume of urine produced on the cold day:

   $\text{(mean on cold day)} = \frac{890 + 1060 + 930 + 1280 + 680 + 1160}{6} = 1000 \text{ cm}^3$

2. Determine the difference between the mean volumes:

   $1000 \text{ cm}^3 - 400 \text{ cm}^3 = 600 \text{ cm}^3$

Therefore, the difference between the mean volumes is 600 cm³.

On hot days, the body loses water primarily through sweating.

This results in a decreased volume of urine produced, as the body conserves water to maintain hydration.

Conversely, on cold days, less water is lost through sweat, leading to an increased volume of urine production as the body can afford to eliminate more waste.