Fruits and colours

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jolly

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Fruits and colours
« on: 25/06/2007 23:10:35 »
Why are lemons Yellow and oranges orange, what dictates a fruits colour?

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Offline Karen W.

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« Reply #1 on: 26/06/2007 02:47:32 »
 What good Questions!!!!

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paul.fr

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Fruits and colours
« Reply #2 on: 26/06/2007 08:37:33 »
Lemons are yellow because their skins absorb all wavelengths of visible light except for the wavelengths corresponding to the color we know as yellow.

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Offline Karen W.

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« Reply #3 on: 26/06/2007 08:49:22 »
Cool Thanks Paul!

"Life is not measured by the number of Breaths we take, but by the moments that take our breath away."

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paul.fr

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Fruits and colours
« Reply #4 on: 26/06/2007 08:53:38 »
the chemicals in the skin/rind may also have an influence on the colour.

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Offline _Stefan_

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« Reply #5 on: 26/06/2007 12:42:26 »
Yes, it's pigmentation, not structural colour.
Stefan
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jolly

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« Reply #6 on: 28/06/2007 23:19:45 »
Yes fine but why? what is it that made the lemon gain a yellow and not a red or pink colour?

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Offline _Stefan_

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« Reply #7 on: 29/06/2007 07:22:50 »
Because their genes cause them to produce yellow pigments but not red.

http://en.wikipedia.org/wiki/Chromatophore

http://en.wikipedia.org/wiki/Biological_pigment
Stefan
"No testimony is sufficient to establish a miracle, unless the testimony be of such a kind, that its falsehood would be more miraculous than the fact which it endeavors to establish." -David Hume

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jolly

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Fruits and colours
« Reply #8 on: 29/06/2007 22:13:15 »
Because their genes cause them to produce yellow pigments but not red.

http://en.wikipedia.org/wiki/Chromatophore

http://en.wikipedia.org/wiki/Biological_pigment

Is that an answer?

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Offline _Stefan_

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« Reply #9 on: 30/06/2007 05:20:52 »
What kind of answer do you want? Have you tried researching plant biology?
Stefan
"No testimony is sufficient to establish a miracle, unless the testimony be of such a kind, that its falsehood would be more miraculous than the fact which it endeavors to establish." -David Hume

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Offline WylieE

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« Reply #10 on: 03/07/2007 17:38:34 »
Hi Jolly,
 Good question!  I'll give a quick answer now with a bit that I know and try to do some more research and get you a better answer.  So really it depends on how the fruit is dispersed.  So in this case fruit color is similar to flower color.  Plants attract the best pollinators by 'advertising' with colors that the best pollinators like.  It is similar for fruits, although with all the domestication we have done of fruits it isn't that straightforward anymore.  However, fruits that are typically eaten by birds and mammals tend to have bright flashy colors- reds, yellows, orange, things that stand out dramatically against the green forest.  So these fruits seem to say "here I am pick me and disperse the seeds."  Birds and mammals are a great choice for a plant because they will spread the seeds far.
  Some fruits stay green because the plant actually needs to do photosynthesis in the fruit while the seeds are growing.   The whole process of how a fruit changes colors is very fascinating.