why are trees green???

Question: why are trees green???

Asked by jacobs97 to Antonia, Douglas, Hugh, Matt, Tom on 22 Jun 2010 in Categories: General. This question was also asked by megannedwardss.
- Hugh Roderick answered on 18 Jun 2010:
  
  Trees are green because all of the cells that make up the leaves contain little packets (called chloroplasts) of the pigment chlorophyll. And this pigment absorbs red light and blue light, but reflects green light so that is why leaves look green. The reason that trees and all plants have this chlorophyll is that they use it to absorb energy from sunlight and transform it into energy that the tree or plant can use to grow. So when we eat green plants we are getting energy that originally came from the sun, and the same is true if we eat animals that eat green plants or animals that have eaten animal that eat green plants, and so on up the food chain. All the energy that animals are able to get comes originally from the sun, which is why green plants are so important, not just for producing oxygen for us to breath but also energy so we can grow.
- Matthew Hurley answered on 18 Jun 2010:
  
  Chlorophyll is green and trees and plants need chlorophyll to make energy.
- Douglas Blane answered on 19 Jun 2010:
  
  Trees, grass and plant leaves are all green because they have something called chlorophyll in them. This is amazingly useful stuff. Its what plants use to capture the energy in sunlight.
  
  A leaf or blade of grass is a wee factory for capturing sunlight energy and making the building blocks for the rest of the plant. These building blocks all start with a simple sugar called glucose.
  
  That whole bit – from capturing the sunlight to making glucose – is called photosynthesis. Besides being very useful itself – because it’s where all the energy in food comes from – it also has a useful side-effect.
  
  It gives off oxygen which the plant throws away into the air. That’s where all the oxygen we breathe comes from.
  
  So trees are green because they contain chlorophyll, which is doing photosynthesis.
  
  But why green? Well sunlight contains all the colours in it – you can see that when raindrops split it up to make a rainbow.
  
  But chlorophyll only uses the blue light and the red light. So it takes them in and lets the green go on its way.
  
  Trees are green, funnily enough, because they have no use for green light.
- Tom Hardy answered on 22 Jun 2010:
  
  The trees are green because of a molecule called chlorophyll. Chlorophyll absorbs sunlight and uses its energy to synthesise carbohydrates from CO2 and water in a process called photosynthesis.

Question: why are trees green???

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