We do see a variety of plants existing all around us near our homes, in the school ground, on the way to the school, in the parks and gardens, isn’t it?
Based on these characters most plants can be classified into three categories: herbs, shrubs and trees, climbers and creepers.
2. Introduction:
Go outside and observe all the plants around you. Do you see that some
plants are small, some very big, while some are just patches of green on
the soil? Some have green leaves, while some others have reddish ones.
Some have huge red flowers, some have tiny blue ones, while some
have none.
3. We do see a variety of plants existing all around us near our homes,
in the school ground, on the way to the school, in the parks and
gardens, isn’t it?
Based on these characters most plants can be classified into three
categories: herbs, shrubs and trees, climbers and creepers.
4. HERBS
Herbs are small plants which have soft stem. Examples: Wheat,
paddy, cabbage, grass, coriander etc.
Grass
Wheat
Paddy
5. SHRUBS
These are bushy and medium- sized plants and they are somewhat
bigger than herbs.
Their branches start from just above the ground. Examples: Lemon,
Coriander, Henna, Rose etc.
6. TREE
These are tall and large plants with hard and woody stem. A single
main-stem arises from the ground.
The main-stem is called trunk. The trunk gives out many branches
at certain height.
The branches carry leaves, flowers and fruits. Examples: Mango,
banyan, acacia, coconut, poplar, willow etc.
Trunk
7. CLIMBER
Plants with weak stem that needs support is called climber.
Examples: Grapevine, money-plant, cucumber, bean etc.
8. CREEPERS
Plants with weak stem that cannot stand upright and spread on the
ground are called creepers. Examples: Pumpkin, Watermelon, sweet
potato etc.
9. PARTS OF PLANT AND THEIR FUNCTION
Each part of the plant has its own work to do. All these parts work
together to keep the plant alive. There are two main parts of plant. One
is shoot and the other is root.
10. ROOT:
The part of the plant that grows under the soil is called as root.
Different plants have different types of roots.
11. THE SHOOT
The part of plant that grows above the soil is called the shoot. Stem,
branches, leaves, flowers and fruits are all the parts of shoot.
Shoot
12. ROOTS
The underground part of a plant is called root. It is usually pale in colour.
The root is a very important component of the plant system, as, without
the presence of roots the plant ceases to exist.
13. FUNCTION OF ROOTS
Roots are responsible for absorbing minerals and water from the soil
and transferring them to the stem.
And the stem becomes capable of transporting these to all parts of
the plant.
14. Another important function of roots helps in holding the plant
firmly to the soil. They anchor the plant to the soil. This is essential
to support the upright position of the plants.
15. Roots also perform the function of storing important nutrients and
food for growth.
There are two major types of roots: Roots are two types: tap root
and fibrous roots.
16. TAP ROOT
This is composed of a main root which grows from the base of the
stem.
Many branches and sub-branches come out of the main root (tap
root). Examples: pea, radish, carrot, mango, marigold, mustard etc.
17. FIBROUS ROOT
In this type, a cluster of thin fibre-like roots arise from the base of
the stem.
These roots spread out in the soil. Examples: Maize, grass, wheat,
millet, etc.
18. AERIAL ROOTS
These are roots of plants and trees that grow above the ground
instead of under the ground.
19. STEM
Stem usually grows above the ground. The stem makes the main
structural framework of the plant. The stem bears leaves, branches,
buds, flowers and fruits.
20. The point from where branches or leaves grow is called as node. The
portion of a stem between two consecutive nodes is called the
internodes.
21. FUNCTIONS OF STEM
The stem gives structural support to the plant. It bears branches,
leaves, flowers and fruits. The stem carries water and minerals from
the roots to different parts of the plant.
23. LEAF
The leaves of plants are majorly responsible for performing two
essential functions for the plant’s survival and growth.
These two functions are called transpiration and photosynthesis.
Leaves and stem together form the shoot.
24. The leaf is a thin, flat and green structure which arises from the
node of the stem.
The green colour of leaves is due to the presence of chlorophyll.
Chlorophyll is a green-coloured pigment.
25. The flat green portion of the leaf is called leaf-blade or lamina. The
leaf is attached to the stem by a short stalk; called petiole.
Small lines present on a leaf are called its vein.
These gives support and transport water and mineral through the
leaf.
A thick vein in the middle of the leaf is called midrib.
26. VENATION
Arrangement of veins in a leaf is called venation. We distinguish
between two major types of leaf venation.
VEINS
27. RETICULATE VENATION
When the veins make a network like structure, it is called reticulate
venation. This type of venation is seen in dicots like guava, mango,
jackfruit, etc.
28. PARALLEL VENATION
When the veins run parallel to each other, it is called parallel
venation .This type of venation is in monocots like banana, wheat,
coconut, leaves of paddy, wheat, grass, etc.
29. PHOTOSYNTHESIS
Green leaves prepare food for plants by using water and carbon
dioxide in the presence of sunlight. This process is called as
photosynthesis.
30. FUNCTIONS OF LEAF
Loss of water vapour from plants through the stomata is as called
transpiration. A major portion of transpiration happens through
stomata.
31. STOMATA
There are many small openings on the lower surface of a leaf. These
are called stomata.
Stomata allow gases to enter or exit the leaf. Unwanted water is also
removed through stomata; in the form of water vapour.
32. REPRODUCTION
Leaves of some plants helps in reproduction also. For e.g. leaves
of Bryophyllum give rise to a new Bryophyllum plant.