Class 6 chapter 2 Diversity in the Living World science

 

Diversity in Plants and Animals Around Us :-

Diversity in plants and animals means the variety of living organisms found in our surroundings. Different plants and animals have different shapes, sizes, habits, and habitats.

Diversity in Plants

Plants are found in many forms, such as:

• Trees (tall and strong)
• Shrubs (medium-sized plants)
• Herbs (small and soft plants)
• Climbers and Creepers (plants that need support or spread on the ground)

Plants also differ based on where they grow:

• Terrestrial plants grow on land
• Aquatic plants grow in water

Diversity in Animals

Animals also show great variety. They differ in:

• Size and shape (small insects to large elephants)
• Food habits (herbivores, carnivores, omnivores)
• Movement (walking, flying, swimming, crawling)

Animals live in different habitats:

• Terrestrial animals live on land
• Aquatic animals live in water
• Amphibians live both on land and in water

Importance of Diversity

• Helps maintain balance in nature
• Provides food, shelter, and resources
• Shows how living beings adapt to their environment

Grouping of Living Organisms :

Living organisms are grouped based on their similarities and differences. This process is called classification, and it helps us study them easily.

Main Groups:

• Plants:
  Make their own food by Photosynthesis and remain fixed in one place.
• Animals:
  Cannot make their own food and can move from place to place.
• Microorganisms:
  Very tiny organisms like bacteria and fungi, seen only with a microscope. 

Grouping Based On:

Habitat:

Terrestrial (land), Aquatic (water), Amphibians (land & water)

Food Habit:

Herbivores, Carnivores, Omnivores

Body Structure:

Vertebrates (with backbone), Invertebrates (without backbone)

Grouping helps us understand and study the large variety of living organisms in a simple and organized way.

Types of Plants :-

1. Herbs

• Small plants with soft, green stems
• Usually live for a short time
• Examples: mint, grass

2. Shrubs

• Medium-sized plants with hard, woody stems
• Branches grow near the base
• Examples: rose, hibiscus

3. Trees

•Tall and large plants with a strong, thick trunk

•Live for many years

•Branches grow high above the ground

Examples: mango, neem

Leaf Venation

Leaf venation is the arrangement of veins and veinlets in a leaf.

1. Reticulate Venation

• Veins form a network (net-like pattern)
• Common in dicot plants

Examples: Mango leaf, Peepal leaf

Feature: Veins are irregular and interconnected

2. Parallel Venation

• Veins run parallel to each other from base to tip
• Common in monocot plants

Examples: Grass, wheat, banana

Feature: Veins are straight and do not form a network

Types of Roots

Roots are mainly of two types:

1. Taproot System

• Has one main root (primary root) that grows deep into the soil
• Smaller side roots branch out from it

Features:

• Grows deep into the soil
• Provides strong support
• Common in dicot plants

Examples: Mustard, carrot, neem

2. Fibrous Root System

• Consists of many thin roots of similar size
• No main root; roots spread out like a bunch

Features:

• Grows near the surface
• Helps in preventing soil erosion
• Common in monocot plants

Examples: Grass, wheat, rice

Monocot and Dicot Plants

Plants are grouped into monocots and dicots based on the number of seed leaves (cotyledons).

Monocot Plants

• One cotyledon (one seed leaf)
• Leaves have parallel venation
• Fibrous root system
• Flowers in multiples of 3

Examples: Rice, wheat, maize, grass, banana

Dicot Plants

• Two cotyledons (two seed leaves)
• Leaves have reticulate venation
• Taproot system
• Flowers in multiples of 4 or 5

Examples: Pea, bean, mustard, mango

Grouping of Animals Based on Movement

Animals can be grouped according to how they move from one place to another (locomotion).

1. Walking Animals

• Move using legs
• Walk slowly or normally

Examples: Cow, dog, elephant

2. Running Animals

• Move fast on legs

Examples: Horse, deer, cheetah

3. Crawling Animals

• Move by sliding their body on the ground

Examples: Snake, earthworm

4. Flying Animals

• Move in the air using wings

Examples: Birds, bat, butterfly

5. Swimming Animals

• Move in water using fins or body movements
• Swimming animals have Streamlined body

Examples: Fish, whale

6. Hopping/Jumping Animals

• Move by jumping

Examples: Frog, kangaroo, rabbit

Plants and Animals in Different Surroundings

Different places (surroundings) have different conditions like temperature, water, and soil. Plants and animals living there show special adaptations to survive.

1. Desert (Hot & Dry)

Plants:

• Cactus, date palm
• Thick stems store water, leaves become spines

Animals:

• Camel, lizard, snake
• Can survive with less water, active at night

2. Mountain (Cold & Windy)

Plants:

• Pine, fir
• Cone-shaped, needle-like leaves to reduce water loss

Animals:

• Yak, snow leopard
• Thick fur to keep warm

3. Grassland

Plants:

• Grass, small shrubs
• Grow quickly and cover large areas

Animals:

• Lion, deer, zebra
• Fast runners to hunt or escape

4. Aquatic (Water)

Plants:

• Lotus, hydrilla
• Float or stay submerged

Animals:

• Fish, whale, frog
• Streamlined body for swimming

5. Forest

Plants:

• Tall trees, dense vegetation

Animals:

• Tiger, monkey, birds
• Adapted for climbing, flying, or hiding

Habitat and Adaptation 

 Habitat

• Habitat is the natural place where an organism lives.
• It provides all basic needs: food, water, air, shelter, and suitable temperature.

Types of Habitat

(A) Terrestrial Habitat (Land)

Organisms live on land.

Examples:

• Desert
• Forest
• Grassland
• Mountain

(B) Aquatic Habitat (Water)

Organisms live in water.

Types:

• Freshwater (ponds, lakes, rivers)
• Marine (seas, oceans)

 Components of Habitat

(A) Biotic Components (Living)

• Plants
• Animals
• Microorganisms

(B) Abiotic Components (Non-living)

• Air
• Water
• Soil
• Sunlight
• Temperature

 Adaptation

• Adaptation is the presence of special features or habits that help an organism survive in its habitat.
• These features develop over a long period of time.

Importance of Adaptation

• Helps organisms survive in their environment
• Helps in finding food and shelter
• Protects from enemies
• Ensures continuation of species

Conservation of Biodiversity 

1. Biodiversity

• Biodiversity means the variety of living organisms (plants, animals, microorganisms) present on Earth.

2. Conservation of Biodiversity

• Conservation means protection and proper management of biodiversity.
• It helps in maintaining the balance of nature.

3. Importance of Conservation

• Maintains ecological balance
• Protects endangered species
• Provides resources like food, medicine, and shelter
• Preserves natural beauty and environment

4. Causes of Loss of Biodiversity

• Deforestation (cutting of trees)
• Pollution (air, water, soil)
• Overhunting and poaching
• Urbanization and industrialization
• Climate change

Wildlife Sanctuaries

Definition

• Wildlife sanctuaries are protected areas where wild animals and plants are conserved in their natural habitat.

Features

• Animals can move freely
• Hunting and poaching are strictly prohibited
• Natural environment is protected
• Limited human activities may be allowed

Importance

• Protects endangered species
• Maintains ecological balance
• Preserves biodiversity
• Provides safe habitat for wildlife

Examples (India)

• Bharatpur Bird Sanctuary
• Gir Wildlife Sanctuary

Project Tiger 

• Project Tiger is a wildlife conservation program started by the Government of India to protect tigers.
• It was launched in 1973.

Objective

• To protect tigers from extinction
• To conserve their natural habitat
• To maintain ecological balance

Protected Forests 

Definition

• Protected forests are forest areas that are protected by the government to conserve trees, wildlife, and natural resources.