Question: how do plants keep us alive

Emma Bennett answered on 18 Jun 2011:

In so many different ways. Firstly they undergo a process called photosynthesis which is where they use the energy from the sun to convert carbon dioxide into oxygen and sugars. The oxygen that they put into the air is needed by us (and other animals) so that we can breathe. Carbon dioxide is also a greenhouse gas so removing some of this from the atmosphere might help cool the earth – although during the night when the sun has gone down plants will respire just like us – taking in oxygen and giving out carbon dioxide.

Plants also provide food for humans and are very important in areas where people don’t keep livestock and only have plants to survive from. They also make up the feed which is given to animals which and we can then eat the animals – so directly and indirectly plants help feed us.

Plants are also a fuel source, be it bio-ethanol to run cars on or wood that can be used to heat things up – like a camp fire to cook food on. In fact coal which is used to produce electricity and heat comes from plants that fell into swamps millions of years ago.

The wood from trees can be made into houses that keep us warm during the winter and this helps keep us alive by protecting us from the elements.

A lot of compounds in plants can also be put into medicines that keep us healthy for example poppy’s can be used to produce the pain relief drug morphine.

I’m sure that plants do lots of other things to help keep us alive but I think I’ve covered the main ways, if you can think of any more though then let me know.