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Chapter 7 Plants

Plants can be found everywhere. Plants are very important to
us as they produce most of the food that humans and animals
eat. There is presence of plant even in meat. Meat yielding
animals such as chickens and goats feed on plants. Without
plants they would die. Hence, most of the food that we eat
comes from plants. Plants also give us shelter, fresh air, fuel
and medicine.

Structure of a leaf
A leaf is an organ of a plant and is the principal
appendage of the stem. Typically a leaf is a thin,
fla ened organ, borne above ground and
specialized for photosynthesis. A leaf is on
external part of a plant's stem. Leaves are the
principal structure, in size leaves range from
only several millimeters long to 15 to 18m long,
as in some palm trees.

Leaves are of different colours and sizes. Green leaves derive their colour from a green
pigment called chlorophyll. The presence of addi onal pigments causes other leaf
colours such as red in coleus and purple in cabbage.

leaf of coleus leaf of cabbage
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