GoalReview the plants unit: groups, the leaf, photosynthesis, adaptation, human impact and the Red Book.
New words
lichen · lishaynikbiodiversity · biologik xilma-xillikcultivated · madaniy
Explanation
In this lesson we review what we know about plants. Recall the plant groups: algae, mosses, ferns, conifers and flowering plants. In a leaf, with chlorophyll and sunlight, carbon dioxide and water become sugar and oxygen. Plants adapt to their surroundings: a desert plant saves water, a humid-forest plant strives for light. People harm and help plants, and rare species are protected by the Red Book. An interesting example: a lichen is a living partnership between a fungus and an alga. The alga makes food, while the fungus protects it and supplies water. Lichens grow on rocks and trees in the mountains as grey, yellow or dark crusts.
Worked examples
The agave is a desert plant (thick fleshy leaves store water); philodendron is a plant of the humid tropical forest.
A wrong statement about photosynthesis: “The leaf takes in oxygen and gives out carbon dioxide.” Correct: the leaf takes in carbon dioxide and gives out oxygen.
Class activity
“Find the mistake”: the teacher reads six statements about plants, two of them wrong. Pupils spot and correct the wrong ones.
Practice
1
Name the five plant groups.
algae, mosses, ferns, conifers, flowering plants
2
What is a lichen and who lives together in it?
A partnership of a fungus and an alga.
3
Where does a plant with thick, fleshy, spiny leaves grow: in the desert or in the humid tropical forest?
In the desert: thick leaves store water, spines save water.
4
Is planting a tree helpful or harmful to nature? Why?
Helpful: it gives oxygen, protects soil and shelters animals.