CBSE Class 6 Science Getting to know Plants Notes

Topics in the chapter

- From where does a plant come?
- Classification of plants on the growth habit
- Classification on the basis of life cycle
- Parts of plants and their functions

From where does a plant come?

- A plant comes from a seed.
- This seed is covered with seed coats, which protect the seed.
- This seed contain a baby plant inside, it has a tiny root towards the outer side.
- The tiny root is termed as radicle.
- It also has a tiny shoot towards the inner side.
- The tiny shoot is termed as plumule.

Classification of plants on the growth habit

- The plants are classified in five types based on growth habit:
(i) Herbs
(ii) Shrubs
(iii) Trees
(iv) Climbers
(v) Creepers
(i) Herbs

- Have soft, green and weak stems. Usually its height is short and may not have many branches. It is used for food, flavouring, medicine or perfume.
- Examples: rice, wheat, maize,sunflower, mint, etc.

(ii) Shrubs
- They are bushy and have hard stems which do not bend easily.These plants have their stem branching out near the base.
- Examples: lemon, China rose, jasmine, etc.

(iii) Trees
- These are big plants which have strong and long stem. Live for many years.
Examples: mango, neem, banyan,coconut, etc.

(iv) Climbers
- Plant that take support on neighbouring structures and climb up are called climbers. It has weak stems and cannot stand erect.
- Examples: pea, grapes etc.

(v) Creepers
- Plants which creep on the ground and spread out is called creepers. It  has weak stems that cannot stand upright. Example: pumpkin and watermelon.

Classification of Plants on the basis of life cycle

- The Plants are classified in three types on the basis of life cycle:
(i) Annuals
(ii) Biennials
(iii) Perennials

(i) Annuals: Plants whose life cycle is completed in one season.
Examples: wheat and mustard.
(ii) Biennials: Plants whose life cycle requires two seasons for completion. Example: carrot, radish and potato.
(iii) Perennials: Plants whose life cycle runs for more than two seasons. Example: guava, babul and palm trees.

Parts of plants and their function

- Plants are divided in 3 types based on their functions:
(i) Root System
(ii) Shoot System
(iii) Flowers

(i) Root system
- The underground part of a plant is called root.

Types of root system:
(a) Tap root system
- Primary root comes out from the seed after germination. It is also called true roots.
(b) Fibrous root system
- These roots grow from the base of the stem have a bushy appearance. Fibrous roots are thin and almost equal in size.

Functions of roots
- Help to anchor the plant firmly into the ground.
- Root help plants to absorb water and nutrients from soil.

(ii) Shoot system
- All parts of a plant that are above the ground form the shoot system.
Types of shoot system:
(a) Stem
- It holds leaves in position and helps them to spread out as the stem and its branches grow. - It bears flowers, buds, leaves, and fruits.
(b) Leaf
- A leaf is a flat and green structure on a plant, coming out from a node on the stem and always bearing a bud in its axil.
- Parts of leaf are:
- Petiole
- Leaf lamina
- Veins

(iii) Flowers
- A flower is the reproductive organ of a plant.
- Flower gets developed into fruits and the fruits contain seeds with them for next generation.

Parts of flowers:
(i) Pedicle: Stalk of the flower through which the flower is joined to the branch.
(ii) Sepal: Small green leaf-like structure on the thalamus.
(iii) Petals: Petals attract the insects and help in the process of reproduction.
(iv) Stamens: These are male organs of the flower. It consists of two parts:
(a) Anther
(b)Filament

(v) Carpel: It is female organ of the flower. It consists of three parts:
(a) Style
(b) Stigma
(c) Ovary