plants

1. FUNCTIONS OF A LEAF continued
• PHOTOSYNTHESIS: Photosynthesis is defined as the process which helps leaves
prepare food for the plant with the help of carbon-di-oxide and water in the
presence of sunlight and a green pigment (in leaves) called chlorophyll.
• The food prepared is stored in various parts
of the plant in the form of starch.
• ACTIVITY: In order to see if leaves really do
perform photosynthesis, let us take a leaf and
immerse it in a test tube filled with spirit.
• Place this test tube in a beaker filled with
water; then heat the beaker.
• After the leaf loses its colour, wash it and
pour iodine solution over it.
• We can see that it turns blue-black in
colour; this shows the presence of starch.
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2. ROOTS
• The root is a very important component of the plant system for the
simple reason that in its absence, the plant ceases to exist.
• Roots generally grow under the ground.
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3. TYPES OF ROOTS
• There are two major types of roots which exist in plants.
• TAP ROOTS: In this type of root system, there is a prominent and long root
and a bunch of smaller roots which grow from this main root called lateral
roots.
• Plants showing reticulate venation in leaves have tap roots.
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CORIANDER
RADISH

4. TYPES OF ROOTS continued
• FIBROUS ROOTS: In this type of root system, a group of similar-sized
roots emerge from the base of the plant. They do not have a main root.
• Plants showing parallel venation in leaves have fibrous roots.
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GRASS RICE (PADDY)
WHEAT

5. FUNCTIONS OF ROOTS
• Roots are responsible for absorbing minerals and water from the
soil and transferring them to the stem.
• Another important function of roots is to firmly anchor the plant in
the ground. This is essential to support the upright position of the
plants.
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6. FUNCTIONS OF ROOTS continued
• Roots also perform the function of storing important nutrients and
food for growth.
• There are some roots which are edible.
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CARROTS BEET ROOT RADISH TURNIP

7. FLOWERS
• Flowers are the colourful, seed-
bearing parts of a plant which grow
at the end of the stem.
• They are the reproductive part
of a plant.
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HIBISCUS ROSE
PETUNIA LILY
DAHLIA CHRYSANTHEMUM

8. PARTS OF A FLOWER
• A flower typically consists of the following parts:
• RECEPTACLE: It is the base of a flower to which all the parts of a flower
are attached.
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9. PARTS OF A FLOWER
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10. PARTS OF A FLOWER continued
• SEPALS: They are the green leaf-like parts in the outermost circle of
a flower. All sepals taken together are called Calyx.
• They protect the flower during its bud stage.
• Some flowers have jointed sepals, while some have separate sepals.
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JOINTED SEPALS OF DATURA SEPARATE SEPALS OF ROSE

11. PARTS OF A FLOWER continued
• PETALS: These are colourful, together known as corolla, and are
present inside the sepals.
• They attract insects for pollination and protect the reproductive organs
of the flower.
• Some flowers have jointed petals and some others have separate
petals.
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JOINTED PETALS SEPARATE PETALS

12. PARTS OF A FLOWER continued
• STAMEN: It is the male reproductive part. It consists of anther and
filament.
• The anther is a sac-like structure that produces and stores pollen.
• The filament supports the anther.
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13. PARTS OF A FLOWER continued
• PISTIL/CARPEL: It is the female reproductive part. It is comprised of
three parts- stigma, style and ovary.
• Stigma is the top-most part of a carpel. It is sticky and receives pollen during
pollination.
• The style is the long tube which connects the stigma to the ovary.
• The ovary contains a lot of ovules.
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14. BRAINTEASERS
• Do all flowers have sepals, petals, stamens and pistils?
• Are there flowers that do not have one or more of these?
• Are there flowers which have parts other than these?
• Do all flowers have the same number of sepals, petals, stamens and
pistils?
• Are the number of sepals and petals in a flower always the same?
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