You answered that water is non-living but was once part of a living thing or that water is non-living and was never part of a living thing.

You are correct in either case!

It is impossible to know the origin of the water in the question. All of the water in the biosphere is involved in the water cycle. Any sample of water is likely to have been part of a living thing during its movement through the water cycle. A small amount of water enters the Earth's atmosphere as ice crystals originating from space. This water joins the cycle as atmospheric water vapour which eventually forms clouds.

Now try question 5

© Shirley Burchill 2009