CBSE Class 6 Science Revision Notes Chapter 2: Diversity in the Living World

Diversity in the Living World describes the variety of plants and animals found in different regions and surroundings. In the CBSE Class 6 Science chapter, organisms are grouped by their features, movements, habitats and adaptations.

Diversity in the Living World introduces the wide variety of plants and animals found around us. Plants differ in their stems, leaves, roots, flowers and seeds. Animals differ in their food, movement, body parts and places of living.

These CBSE Class 6 Science Revision Notes Chapter 2 follow the current 2026–27 chapter. Use them to revise biodiversity, plant groups, animal movement, habitats, adaptations and biodiversity conservation.

Key Takeaways

• Biodiversity: The variety of plants and animals found in a particular region forms its biodiversity.
• Plant grouping: Plants can be grouped using their stems, roots, leaf venation and number of cotyledons.
• Habitat: A habitat provides an organism with food, water, air, shelter and other survival needs.
• Adaptation: Special features help plants and animals survive in the conditions of a particular region.

Access Class 6 Science Chapter 2 Diversity in the Living World Notes in 30 Minutes

Revise the chapter in three parts:

• First 10 minutes: Diversity, biodiversity and grouping of plants and animals
• Next 10 minutes: Plant types, leaf venation, roots, monocots and dicots
• Final 10 minutes: Animal movement, habitats, adaptations and biodiversity conservation

Need help revising plant groups, roots, habitats and adaptations?

Access interactive practice, chapter-wise notes and doubt-solving support on the Extramarks Learning App. Sign Up Free

Diversity of Plants and Animals Around Us

Nature contains plants and animals of different shapes, sizes, colours and structures. Even birds can have distinct calls and ways of moving.

Plants around us may be short or tall. Their stems may be hard, soft, thin, thick, green or brown.

Leaves also differ in shape, size, surface and arrangement. Flowers may vary in colour, shape and scent.

Animals also show several differences. They live in different places, eat different foods and move in different ways.

For example:

• Crows may live on trees and move by walking or flying.
• Ants live in nests or burrows and move using six legs.
• Fish live in water and swim using fins.
• Frogs can live on land and in water.

What Is Biodiversity?

The variety of plants and animals found in a particular region contributes to the biodiversity of that region.

A forest may contain trees, shrubs, herbs, birds, insects and mammals. A pond may contain aquatic plants, fish, frogs and insects.

Each member of a region’s biodiversity has a role. Trees provide food and shelter to birds and other animals. Animals may spread seeds after eating fruits.

This shows that plants and animals are dependent on one another.

Grouping of Plants and Animals

There are many kinds of plants and animals. Studying each organism separately can become difficult.

Grouping arranges plants and animals according to their common features. It helps us understand their similarities and differences.

Plants may be grouped according to:

• Height
• Nature of the stem
• Branching pattern
• Presence or absence of flowers
• Leaf venation
• Root type
• Number of cotyledons

Animals may be grouped according to:

• Food habits
• Place of living
• Colour
• Body structure
• Type of movement
• Body parts used for movement

Different people may choose different features for grouping. A plant can also belong to different groups depending on the selected feature.

Grouping Plants in Class 6 Science Chapter 2 Notes

Plants show variations in their height, stems, branches, leaves, roots and seeds. These features help us place them in different groups.

Herbs, Shrubs and Trees

Plants can be grouped as herbs, shrubs and trees using their height, type of stem and branching pattern.

Herbs

Herbs are usually small plants. They have soft, green and tender stems.

Their stems can often bend easily. Tomato is an example of a herb.

Shrubs

Shrubs are not as tall as trees. They usually have several hard and woody stems.

Their branches start close to the ground. Rose is an example of a shrub.

Trees

Trees are tall plants with hard, thick and woody stems. Their branches usually begin higher above the ground.

The main woody stem of a tree supports its branches. Mango is an example of a tree.

Climbers and Creepers

Some plants have weak stems that cannot remain upright without support.

Climbers use support to climb and grow upwards. Creepers spread and grow along the ground.

Leaf Venation in Diversity in the Living World

Leaves contain thin lines called veins. The arrangement or pattern of veins in a leaf is called venation.

There are two main types of venation in this chapter.

Reticulate Venation

In reticulate venation, veins form a net-like pattern on both sides of a thick middle vein.

Hibiscus leaves have reticulate venation.

Parallel Venation

In parallel venation, the veins run parallel to one another.

Banana and grass leaves have parallel venation.

Taproot and Fibrous Root Systems

Plants can also be grouped by their root systems. The chapter introduces taproots and fibrous roots.

Taproot

A taproot system contains one main root. Smaller side roots arise from this main root.

Mustard and hibiscus are examples of plants with taproots.

Fibrous Root

A fibrous root system contains a bunch of thin roots of similar size. These roots arise from the base of the stem.

Grass is an example of a plant with fibrous roots.

Relationship Between Roots and Leaf Venation

The type of leaf venation is generally related to the root system of a plant.

Plants with reticulate venation generally have taproots. Plants with parallel venation generally have fibrous roots.

Examples include:

• Sadabahar: Reticulate venation and taproot
• Lemongrass: Parallel venation and fibrous roots
• Chickpea: Reticulate venation and taproot
• Wheat: Parallel venation and fibrous roots

The word “generally” is important because the chapter presents this as a common relationship.

Monocot and Dicot Plants

A seed contains one or more seed leaves called cotyledons. Plants can be grouped according to the number of cotyledons in their seeds.

Dicotyledons or Dicots

Dicot seeds contain two cotyledons. Chickpea is an example of a dicot plant.

Dicot plants generally have:

• Two cotyledons
• Reticulate venation
• A taproot system

Monocotyledons or Monocots

Monocot seeds contain one cotyledon. Maize is an example of a monocot plant.

Monocot plants generally have:

• One cotyledon
• Parallel venation
• A fibrous root system

Quick Connection Between Seeds, Roots and Leaves

Use this pattern for quick revision:

Dicot → Two cotyledons → Reticulate venation → Taproot

Monocot → One cotyledon → Parallel venation → Fibrous roots

Grouping Animals by Movement

Animals show different types of movement. Their movement and the body parts used can become a basis for grouping.

Animals may walk, run, crawl, hop, jump, fly or swim.

Animals with similar movements may still have other differences. A pigeon and a housefly can both walk and fly, but their size and body structures differ.

Animals may also be grouped by their shape, size, colour, structure, food and habitat.

Plants and Animals in Different Surroundings

Different regions have different temperatures, water availability, landforms and weather conditions. Therefore, the biodiversity of one region may differ from another.

Plants and animals living in a region develop features that help them survive there.

Cactus in the Desert

Deserts receive very little water. They can also be hot during the day and cold at night.

Cactus plants have thick and fleshy stems. These stems store water and help the plants survive dry desert conditions.

Deodar Trees in the Mountains

Cold mountain regions may receive frequent snowfall. Deodar trees have a conical shape with flexible and sloping branches.

This structure allows snow to slide off easily. It prevents large amounts of snow from collecting on the branches.

Hot-Desert and Cold-Desert Camels

Camels found in Rajasthan and Ladakh show differences suited to their surroundings.

The hot-desert camel has long legs and wide hooves. These features help it walk on sand without sinking.

It also loses little water. It passes small amounts of urine, produces dry dung and does not sweat much.

The cold-desert camel has shorter legs that help it move through mountainous regions. It has two humps and grows long hair that protects it during cold Ladakh winters.

Rhododendrons in Different Mountain Regions

Rhododendrons may show different features in different regions.

In the Shola forests of the Nilgiris, they may be shorter and have smaller leaves. These features help them survive strong winds on mountain tops.

Rhododendrons growing in the mountains of Sikkim may be taller. This shows that even similar plants can develop different features under different regional conditions.

Fish in Water

Fish have streamlined bodies. This shape allows them to move easily through water.

They use fins for swimming.

Adaptations in Plants and Animals

The special features that enable plants and animals to survive in a particular region are called adaptations.

Examples of adaptations include:

• Thick, fleshy stems of desert plants
• Conical shape and sloping branches of deodar trees
• Long legs and wide hooves of hot-desert camels
• Long hair of cold-desert camels
• Streamlined bodies of fish
• Different heights and leaf sizes of rhododendrons

An adaptation is connected to the conditions of the place where an organism lives.

Habitats in Diversity in the Living World

The place where a plant or animal lives is called its habitat.

A habitat provides food, water, air, shelter and other conditions needed for survival.

Examples include:

• The sea is the habitat of sea turtles.
• A hot or cold desert is the habitat of camels.
• Mountains are the habitat of rhododendrons.
• Water is the habitat of fish.

Many different plants and animals may share the same habitat.

Terrestrial Habitats

Plants and animals living on land belong to terrestrial habitats.

Examples of terrestrial habitats include:

• Forests
• Deserts
• Grasslands
• Mountains

Goats, lions, camels and deodar trees live in terrestrial habitats.

Aquatic Habitats

Plants and animals living in water belong to aquatic habitats.

Examples of aquatic habitats include:

• Ponds
• Lakes
• Rivers
• Oceans

Fish, whales and many water plants live in aquatic habitats.

Amphibians

Some animals can live on land and in water. Such animals are called amphibians.

A frog is an example of an amphibian.

Habitat Damage and Loss of Biodiversity

Plants and animals depend on their habitats for their survival needs. Damage to a habitat removes food, water, shelter and other resources.

A fish cannot survive without water. A goat cannot survive if it does not find suitable food.

When natural habitats are damaged, the number of plants and animals may decrease. This results in loss of biodiversity.

Human activities have caused habitat loss for species such as:

• Bengal Tiger
• Cheetah
• Great Indian Bustard

Biodiversity Conservation in India

Protecting natural habitats helps plants and animals survive and reproduce. India has started several projects to protect threatened animals and their habitats.

Project Tiger

Project Tiger began in 1973. Its purpose was to protect the declining population of the Bengal Tiger.

Cheetah Reintroduction Project

The Cheetah Reintroduction Project began in 2022. It aims to restore the cheetah population in India.

Great Indian Bustard Protection

Habitats of the Great Indian Bustard have been declared protected areas in Gujarat, Rajasthan and Maharashtra.

Sacred Groves

Sacred groves are undisturbed patches of forests protected by local communities.

People do not cut trees, harm animals or disturb these areas. Sacred groves protect many plants, animals and medicinal plants.

They represent community-based biodiversity conservation.

Indian Scientists Who Helped Protect Biodiversity

Janaki Ammal

Janaki Ammal was an Indian botanist who worked to document and preserve India’s plant biodiversity.

She played an important role in the Save Silent Valley movement. She also headed the Botanical Survey of India and began programmes to document plant diversity.

Salim Ali

Salim Ali travelled across India to observe and document birds, their routes and habitats.

He supported the conservation of regions rich in bird diversity. He is known as the Birdman of India.

Quick Revision Table for Class 6 Science Chapter 2

Important Terms from Diversity in the Living World

Cotyledon: A seed leaf present inside a seed.

Reticulate venation: A net-like arrangement of veins in a leaf.

Parallel venation: An arrangement in which leaf veins run parallel.

Taproot: A main root from which smaller side roots arise.

Fibrous roots: A bunch of similar thin roots arising from the stem base.

Dicot plant: A plant whose seed has two cotyledons.

Monocot plant: A plant whose seed has one cotyledon.

Adaptation: A special feature that helps an organism survive in a region.

Habitat: The natural place where a plant or animal lives.

Sacred grove: A forest patch protected by a local community.

Useful Links for Class 6 Science