☰ Year plan · Science

Light, roots and tubes

Week 2 · Theme 1 Systems, Unit 1 Interactions of Organisms, Concept 1.1 Plant Needs (B) · 3 lessons
2

Roots, stem and leaves at work

Discovery Education Science P5: Term 1, Unit 1, pp. 20–23
GoalName the jobs of roots, stem and leaves, and say what xylem and phloem carry.
New words
roots · plant parts that hold the plant and take in water and mineralsxylem · tubes that carry water and minerals up the plantphloem · tubes that carry sugar from the leaves to the rest of the plantstomata · tiny holes in leaves that let air in
Explanation

Each part of a plant has a job. The roots hold the plant in the ground and take in water and minerals through tiny root hairs. The stem holds the plant up and has tubes inside it. The xylem tubes carry water and minerals up from the roots to the leaves. The leaves make food. They collect light, and air enters through tiny holes called stomata. The phloem tubes then carry the sugar made in the leaves to the roots, stems and growing parts. A plant has no heart: it does not pump anything round, the tubes simply carry the materials. Together, roots, stem and leaves work as one system.

PartJob
Rootshold the plant; take in water and minerals
Stemholds the plant up; xylem and phloem tubes run inside
Leavescollect light and air; make food
Worked examples
This chart follows water and sugar through a plant.
date palmwater below
A date palm in the Siwa oasis has roots that spread deep to find water. They also hold the tall tree firmly so the wind cannot push it over.
rootleaves
Farida picks a lettuce. She eats the leaves, which are the parts that make the plant’s food. A carrot is a root and a lettuce is mostly leaves.
Class activity

Plant parts hunt. With a grown-up, choose a small weed or herb plant in the garden or in a pot. Look closely at its roots, stem and leaves with a magnifier if you have one. Draw it and write the job of each part next to your drawing. Put the plant back in the soil and wash your hands.

Practice
1
The yellow part of the plant is a root. Write two jobs of roots.
2
Which tubes carry water and minerals up: xylem or phloem?
3
What is the highlighted part, and what is its main job?
4
Why does a plant not need a heart to move water?