Getting to Know Plants. Class 6, NCERT NOTES

 

Getting to Know Plants

Introduction

Introduction to plants

Plants are all around us. They help sustain life on earth by creating food and giving out oxygen that we breathe in.

Plants

• Plants are the immovable living organisms all around us.
• They are the primary food providers.
• They are mostly green in colour and use sun as the source of energy to make food.

Herbs, shrubs and trees

• Herbs are the smallest plants and do not have woody stem.
• Shrubs are slightly larger than herbs. They have thin woody stem and branches branching out from the base of the stem. They are smaller than trees.
• Trees are the largest plants and have large and thick woody stem.

Creepers and climbers

Creepers and Climbers are types of plants that need support to grow.

Algae and mosses

• Algae and mosses are the most primitive or simple plants.
• Algae are found mostly floating on water and mosses are seen on surfaces, rocks or bark of trees in humid conditions.

Leaf

Leaf
Leaf is the most important part of the plant. Most leaves of plants are green in colour. There are different shapes and sizes of leaves.
Different parts of a leaf
Leaf has different parts:

• the midrib
• the veins
• the leaf blade/lamina

Transpiration
Transpiration is the loss of water from aerial parts of the plant, especially from leaves. Water is lost in the form of water vapours through tiny openings called stomata, present on the underside of leaves.
Photosynthesis

Photosynthesis is the process by which the plant converts carbon dioxide and water into food using sunlight as the energy source. Photosynthesis happens in green leaves.

Root
Root
The root is the part of the plant that is found under the soil. It provides stability to the plant and also absorbs water and minerals.

Types of roots
There are two types of roots:
 tap root and fibrous root.
Tap roots are seen in large trees and shrubs. Fibrous roots are common in herbs.
Relation between different types of leaves and roots
Leaf venation and the type of roots in a plant are related. Plants with fibrous roots have parallel venation in their leaves. Plants with tap roots have reticulate venation in their leaves.

Stem

Stem
The stem is the main part of the plant. It gives structural support and helps in the transportation of water, minerals, and food. The leaves and branches originate from the stem.

Flower

Flower

A flower is the reproductive part of a flowering plant. The only function a flower serves is reproduction. Different parts of a flower have different functions.

Different parts of flowers and their function

A flower is made up of four important parts. The sepals, the petals, the male stigma and the female style.

Reproduction in flowering plants

Reproduction in flowers happens when the pollen grain from the male androecium fuses with the eggs in the female style.

Seed

A seed is an enclosed dormant embryo of a plant. They are found in the fruits and when sown, gives rise to a new plant.

Parts of a seed

A seed is made up different parts. The . plumule gives rise to the shoot and the radicle grows into the roots. The cotyledons provide nutrition.

Types of seeds

There are two types of seeds on the basis of number of cotyledons. Monocots have single cotyledon. Dicots have two cotyledons.

Food

Food: fruits and vegetables

• Fruits are very different from vegetables.
• Fruits always develop from a flower, while vegetable are parts of the plant that are edible for us, it could be the shoots, the leaves, the roots or even the fruits.
• Tomato is a classic example of a vegetable as a fruit too.