I can see how water gets from the roots of a plant tp the leaves
powered by evaporation and capilliary attraction.
However I don't see how sugars etc get from the leaves to the root,
tubers and fruits of a plant. This implies two way flow.
Anyone know the answers to this?

On Nov 18, 7:53*am, harry wrote:
I can see how water gets from the roots of a plant tp the leaves
powered by evaporation and capilliary attraction.
However I don't see how sugars etc get from the leaves to the root,
tubers and fruits of a plant. This implies two way flow.
Anyone know the answers to this?

Remembering way back to school biology, a plant has two fluid
transport systems - 'Xylem up, phloem down'. Xylem takes fluid (and
thus substances in solution) from root to leaf, phloem the reverse.
Wikipedia seems to agree that what I was taught hasn't changed much:
http://en.wikipedia.org/wiki/Phloem.

Regards,
Martin.

On Nov 18, 7:59*am, Martin_Stevens wrote:
On Nov 18, 7:53*am, harry wrote:

I can see how water gets from the roots of a plant tp the leaves
powered by evaporation and capilliary attraction.
However I don't see how sugars etc get from the leaves to the root,
tubers and fruits of a plant. This implies two way flow.
Anyone know the answers to this?

Remembering way back to school biology, a plant has two fluid
transport systems - 'Xylem up, phloem down'. Xylem takes fluid (and
thus substances in solution) from root to leaf, phloem the reverse.
Wikipedia seems to agree that what I was taught hasn't changed much:http://en.wikipedia.org/wiki/Phloem.

Regards,
Martin.

I always found chemistry and physics more interesting than biology.
Apart from girls that is.
So if I have a melon on a plant, does the sustennace come forme the
leaves between the root and the melon or the tip of the vine and the
melon?

harry wrote:
I can see how water gets from the roots of a plant tp the leaves
powered by evaporation and capilliary attraction.
However I don't see how sugars etc get from the leaves to the root,
tubers and fruits of a plant. This implies two way flow.
Anyone know the answers to this?

Vascular bundles!

It is VERY dangerous to think!

Alan

"harry" wrote in message
...
I can see how water gets from the roots of a plant tp the leaves
powered by evaporation and capilliary attraction.
However I don't see how sugars etc get from the leaves to the root,
tubers and fruits of a plant. This implies two way flow.
Anyone know the answers to this?

On Nov 18, 7:55*pm, "alan.holmes" wrote:
It is VERY dangerous to think!

Alan

"harry" wrote in message

...



I can see how water gets from the roots of a plant tp the leaves
powered by evaporation and capilliary attraction.
However I don't see how sugars etc get from the leaves to the root,
tubers and fruits of a plant. This implies two way flow.
Anyone know the answers to this?- Hide quoted text -

- Show quoted text -

I know. It makes my head hurt!