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Adaptations of animals and plants

الأسبوع 2 · المحور الأول، الوحدة الأولى، المفهوم 1.1 «التكيف والبقاء» (ب): التكيفات التركيبية والسلوكية في الحيوانات والنباتات · 3 دروس
3

Plants that fit their place

Discovery Education Science P4: Term 1, Unit 1, pp. 10–18
GoalExplain how plants have adaptations that fit where they live, and compare how different plants solve the same problem.
New words
taproot · one long root that grows deep down to find waterthorn · a sharp point on a plant that protects it from being eatenmangrove · a tree that grows in salty water at the sea shore
Explanation

Plants cannot walk to water or shade, so their bodies fit the place where they grow. Many desert plants lose very little water. The date palm has long roots that reach water deep in the ground and tough leaves with a waxy skin. The acacia, which grows in Sinai and the Eastern Desert, has a very deep taproot, small leaves that lose less water, and thorns that stop animals from eating it. The prickly pear has thick pads that store water and spines instead of leaves. A water lily has the opposite problem: there is plenty of water, and it must stay on top of it. Its wide, flat leaves lie on the water and its long, bendy stems reach up from the mud. Mangroves grow in the salty sea water of the Red Sea coast, with roots that stand above the mud. A pine tree has thin needle leaves that let snow slide off and lose little water. Different plants solve the same problem, getting enough water, in different ways.

PlantPlaceAdaptation
date palmdesert, oasislong roots, tough waxy leaves
acaciadry landdeep taproot, small leaves, thorns
prickly peardesertthick pads store water, spines
water lilypond, riverfloating leaves, bendy stems
mangrovesalty shoreroots above the mud, copes with salt
pinecold mountainneedle leaves
Worked examples
date palmwater far below
Salma looks at a date palm in an oasis. Its long roots search for water far down, and its leaves are tough and waxy. Both help the palm in a hot, dry place.
prickly pearwater inside
A prickly pear has thick, flat pads and sharp spines. The pads hold water for the dry months, and the spines make it hard for animals to eat it.
A pine tree on a snowy mountain has thin needles instead of wide leaves. Snow slides off them, and they lose little water in the freezing air.
Class activity

Plant detective. With a grown-up, visit a garden, a street or a park and find three different plants. For each one, draw its leaves and write where it lives, what problem the place has (little water, shade, wind) and which part may help. If you cannot go out, look at pictures of plants in a book.

Practice
1
The acacia has thorns. What do they do?
2
Why can a water lily’s leaves float?
3
Two plants both live in the desert: the date palm and the prickly pear. Say one way they solve the water problem differently.
4
Mangroves grow in salty water. Is this an adaptation of the plant’s body or of its behaviour?