To understand how plants grow we need to understand a bit about their anatomy.
Here is a typical plant with its main features labelled.
Place the correct parts next to their corresponding functions and mark your answer to see if you are correct:
Plants obtain their food through photosynthesis but not all parts of the plant can do this. For example, the roots do not get any light.
So how do root cells get the food they need?
Also, the leaves need water for photosynthesis, but how do they get water from the roots?
There has to be a transport system going up and down the plant...
This system is made up of lots of tubes or vessels that branch throughout the plant, like our circulatory system.
Xylem (pronounced "zy-lem") vessels or tubes reach up to the leaves from the roots. They carry water and mineral nutrients to all parts of the plant, especially the leaves.
Water moves from the soil into the roots by osmosis and then flows steadily up the xylem. As water is lost from the leaf by transpiration more water is drawn up through the xylem to replace it. The roots have root hairs on them, this increases their surface area and so allows more water to be absorbed.
Phloem (pronounced "flo-em") tubes carry the sugars such as glucose made in the leaves to all parts of the plant, including the roots. This sugar can then be stored for example as starch in a potato.
The xylem and phloem tubes are often grouped together as they travel through plants into veins and vascular bundles. For example as they pass through leaves and up stems.