06 How Plants Get Water

All living things need water in order to grow and survive. The water that plants need usually comes from rain falling on the ground and soaking into the soil. A plant's roots are able to get water, but the leaves and stems need water, too. So, since water can't move on its own, the different plant parts must work together to move the water.

Roots absorb water from the ground, but not all plants have the same kind of roots. Some plants have tap roots that grow deep into the ground. Tap roots are good for finding water buried deep below the surface. Plants that live in dry areas with hard dirt often have tap roots. Other plants have diffuse roots. These roots spread out far and are good for making sure a plant is strongly supported. Plants that grow in mud or sand often have diffuse roots.

Water that is absorbed by a plant's roots must get to all the cells in the plant. The stem helps with this job. A plant's stem has two parts. The outside of the stem is made from tough fibers to protect it. The inside of the tube is made of long tubes. These tubes move the nutrients upward from the roots.

WordList

absorb : to soak up

diffuse root : a kind of shallow root that spreads out far

tap root : a kind of root that is long and extends deep into the ground

nutrients : substances found in soil that help a living thing stay healthy

You Practice

I. Answer the following questions.

1) What do all living things need?

2) Where do plants usually get their water from?

3) How are tap roots and diffuse roots different?

4) What is the main job of the stem?

5) Where do diffuse roots usually grow?

II. Opposites—Find words in the reading that mean the opposite of these words.

1) shallow: d _ _ _

2) weakly: s _ _ _ _ _ _ _

3) inside: o _ _ _ _ _ _

4) week: t _ _ _ _

5) downward: u _ _ _ _ _

III. Read these sentences carefully. Write Yes or No for each one.

____ 1) Diffuse roots are deeper than tap roots.

____ 2) A plant's leaves and stems need water.

____ 3) A plant's stem has three parts.

____ 4) The stems of some plants can be eaten.

____ 5) Plants cannot grow in mud or sand.