Grade 6 Ch 2 Diversity in the living World

 

Chapter 2 Diversity in the Living World

Introduction: 

The term diversity in the living world refers to the vast variety of plants, animals, and microorganisms found on Earth. Each living organism, from the tiniest bacteria to the largest mammals, plays a unique role in the environment. This diversity ensures the survival of ecosystems and is crucial for maintaining the balance of nature. Studying diversity helps us understand the unique features, behaviours, and adaptations of different organisms, allowing us to appreciate the intricate web of life.

Grouping of Plants

Grouping: Arranging things into groups based on common features is called grouping.

Plants can be grouped into categories based on their characteristics. This makes it easier to study them systematically.

2. Based on Height and Stem Type

• Herbs: These are small plants with soft, green stems. Examples include coriander, spinach, and tomato plants.
• Shrubs: These are medium-height plants with woody stems that branch out near the ground, such as rose and hibiscus.
• Trees: Tall and strong plants with thick, woody trunks and branches that start high above the ground. Examples include mango and neem.
• Creepers: These are plants with weak stems and creep along the ground. Examples- watermelon, muskmellon etc
• Climbers: These are plants with weak stems need support to climb & grow. Examples- money plant, bitter gourd, bottle gourd, grapevine etc

3. Based on Leaves

• Shape and Size: Leaves come in various shapes, sizes, and arrangements. For instance, banana leaves are large and long, while neem leaves are small and narrow.
• Colour: While most leaves are green, some may have reddish or purple hues due to pigments.
• Venation Patterns:
• Reticulate Venation: The veins form a net-like pattern, as seen in dicot plants like hibiscus.
• Parallel Venation: The veins run parallel to each other, found in monocots like maize and grass.

4. Based on Root Systems

    Roots anchor the plant to the ground and absorb water and nutrients. Plants can have:

• Taproots: A single thick root with smaller side roots branching off, as seen in dicots like mustard and hibiscus.
• Fibrous Roots: A cluster of thin roots of similar size, found in monocots like grass and wheat.

5. Based on Seeds

The type of seed helps in further classification:

• Monocot Plants:
• Seeds have one cotyledon.
• Plants have parallel venation and fibrous roots (e.g., rice, maize).
• Dicot Plants:
• Seeds have two cotyledons.
• Plants exhibit reticulate venation and taproots (e.g., mango, chickpea).

6. Based on Flowers

• Flowering Plants: Plants that bear flowers, such as sunflower and rose.
• Non-Flowering Plants: Plants like ferns and mosses, which reproduce through spores instead of flowers.

Patterns of Veins in Leaves

• Reticulate Venation:
• Found in dicots with taproots (e.g., guava).
• The veins branch out from a central midrib, forming a web-like pattern.
• Parallel Venation:
• Found in monocots with fibrous roots (e.g., grass).
• The veins run parallel to each other from the base to the tip.

Roots and Their Functions

Roots play a crucial role in the survival of plants. They:

1. Anchor plants firmly to the ground.
2. Absorb water and nutrients from the soil.
3. Store food in certain plants like carrots and radishes.

Relation Between Roots and Leaf Venation

• Plants with reticulate venation usually have taproots.
• Plants with parallel venation typically have fibrous roots.

Grouping of Animals

Animals can also be classified based on their unique features and habitats.

1. Based on Movement

Animals move in different ways, depending on their body structure and habitat:

• Flying: Birds like pigeons and butterflies use wings.
• Walking or Running: Animals like dogs, cats, and goats use legs.
• Hopping: Frogs and kangaroos.
• Crawling: Snakes and worms move by crawling.
• Swimming: Fish use fins to swim.

2. Based on Habitat

Animals can be grouped by where they live:

• Terrestrial: Live on land (e.g., elephants, ants).
• Aquatic: Live in water (e.g., fish, whales).
• Amphibians: Can live both on land and in water (e.g., frogs).
• Aerial: Spend much of their time flying (e.g., eagles, bats).

3. Based on Adaptations

• Body Structure:
• Fish have streamlined bodies to swim efficiently.
• Camels have wide hooves for walking on sand.
• Special Features:
• Polar bears have thick fur for insulation in cold climates.
• Chameleons can change colour to blend with their surroundings.

Habitats of Plants and Animals

Terrestrial Habitats

• Deserts: Plants like cacti store water in their stems. Animals like camels have adaptations for conserving water.
• Forests: Home to a variety of trees and animals like tigers, monkeys, and deer.
• Mountains: Trees like deodar grow in cold climates. Animals like snow leopards are adapted to harsh conditions.

Aquatic Habitats

• Freshwater: Found in ponds, lakes, and rivers. Examples include lotus plants and fish like rohu.
• Marine: Found in oceans. Examples include seaweed, whales, and coral reefs.

Sacred Groves: Protecting Biodiversity

• Definition: Sacred groves are forest patches protected by local communities for religious or cultural reasons.
• Biodiversity Hotspots: These areas are home to unique plants and animals, including medicinal plants.
• Community Role: Sacred groves showcase how human traditions can contribute to conservation efforts.

Why Grouping is Important

Grouping plants and animals helps in:

1. Understanding similarities and differences.
2. Studying them systematically.
3. Identifying their adaptations and habitats.
4. Appreciating biodiversity and the need for conservation.

 

LET US ENHANCE OUR LEARNING

1. Here are two types of seeds. What differences do you find among the roots and leaf venation of their plants?

                             

Solution:  Wheat plants have fibrous roots and leaves with parallel venation. The Kidney bean plants have taproots and leaves with reticulate venation. 

2. Names of some animals are given below. Group them based on their habitats. Write the names of aquatic animals in the area marked ‘A’ and terrestrial animals in the area marked ‘B’. Enter the names of animals living in both habitats in part ‘ C ‘. Horse, Dolphin, Frog, Sheep, Crocodile, Squirrel, Whale, Earthworm, Pigeon, Tortoise. 

                                                  

Solution:  Aquatic animals (A) = Dolphin and Whale

                  Terrestrial animals (B) = Horse, Sheep, Squirrel, Pigeon and Earthworm.

                   Animals living on land and sea both (C) = Frog, Tortoise and Crocodile .

3. Manu’s mother maintains a kitchen garden. One day, she was digging out radish from the soil. She told Manu that radish is a kind of root. Examine a radish and write what type of root is. What type of venation would you observe in the leaves of radish plant?

Solution:  Tap of Root : Tap root

                   Type of venation : Reticulate. 

4. Look at the image of a mountain goat and a goat found in the plains. Point out the similarities and differences between them. What are the reasons for these differences? 

                

Solution: 

​​​​​​Similarities: Both are goats and belong to the same family. Herbivore diet: Both are herbivores. That is they eat plants including roots, stems, leaves etc.

Differences: 

SR No.	Mountain Goat	Plains Goat
1	Has thick, long fur to protect against cold mountain temperatures	Has shorter fur suited for warmer climates.
2	Generally stockier and more muscular, adapted for climbing rocky terrains.	Leaner build suitable for flat, open areas
3	Specialised hooves with a rough texture for better grip on rocky surfaces.	Hooves more suited for walking on flat, grassy lands.

 

5. Group the following animals into two groups based on any feature other than those discussed in the chapter- cow, cockroach, pigeon, bat, tortoise, whale, fish, grasshopper, lizard.

Solution: ​​​​​​We can group these animals into two groups based on whether they have backbone or not.

Animals which have backbone - Cow, pigeon, bat, tortoise, whale, fish, lizard

Animals which do not have backbone - Cockroach, grasshopper.

6. As the population grows and people want more comfortable lives, forests are being cut down to meet various needs. How can this affect our surroundings? How do you think we can address this challenge?

Solution: ​​​​​​The loss of trees and other vegetation due to cutting down of forests can cause climate change, loss of biodiversity, soil erosion, flooding, etc. We can address this challenge by the following methods 1. Replanting of trees and, putting a ban on cutting of trees. 2. Implementing regulations and laws to address the severity of cutting down the forest. 

7. Analyse the flow chart. What can be examples of ‘A’ and ‘B’. 

                                                               

Solution: ​​​​​​(A) – The plants having leaves with reticulate venation have tap roots.

                 (B) – The plants not having leaves with reticulate venation have fibrous roots. 

8. Raj argues with his friend Sanjay that “Gudhal (hibiscus) plant is a shrub”. What questions can Sanjay ask for clarification?

Solution:

​​​​​​1. What is the nature of its stem?

2. What is the height of the Gudhal (hibiscus) plant?

3. Is the stem of the Gudhal plant woody? 

9. Based on the information in the table, find out examples of these plants for each group. 

Group	Type of seed	Type of root	Examples
A	Dicot	Taproot
B	Monocot	Fibrous roots

 

(a) What other similarity do plants of group A have?

(b) What other similarity do plants of group B have?

Solution:

Group	Type of seed	Type of root	Examples
A	Dicot	Taproot	Gram, beans, bottle ground, mango
B	Monocot	Fibrous roots	Wheat, rice, maize

(a) Plants of group A have reticulate venation.

(b) Plants of group B have parallel venation.

10. Observe the labelled part of a duck in the picture given below. What differences do you observe in the feet of the duck compared to the other birds? Which activity would the duck be able to perform using this part?

                                         

 

Solution: ​​​​​​Ducks use their webbed feet like paddles to provide more surface to push against the water, which helps them to move through the water.