Class 6 Science · Chapter 2

2. Diversity in the Living World

Answers to in-text questions, activities and Let us enhance our learning. NCERT Curiosity, Class 6 Science (CBSE).

Activities

2.1Record your observations about the features of different plants in Table 2.1.

Plant	Stem	Leaves	Flowers	Other features
Common grass	Soft and thin	A single leaf grows alternately from different points on the stem	Green, very small	Grows close to the ground
Tulsi	Hard and thin	A pair of leaves in opposite directions	Pinkish purple	Leaves have a strong smell
Hibiscus	Hard	Broad leaves with toothed edges	Large, red	Has a taproot
Neem	Hard and thick	Leaves with smooth surface	Small, white	Leaves are bitter
Mango	Hard, thick and brown	Long and pointed	Small, yellowish, in bunches	Big, shady tree

Fill the table with plants you observe on your own nature walk.

What similarities and differences did you find among the plants that you observed?

Similarities: All plants have roots, stems and leaves. All have green leaves.

Differences: Some plants are tall, some are short. Some have hard stems, some have soft stems. Leaves differ in shape and arrangement. Flowers differ in colour, shape and smell.

Record the places where animals live, the food they eat and the way they move in Table 2.2.

Animal	Place where it lives	Food	Movement	Other features
Crow	Tree	Insects	Fly and walk	Carries a twig in its beak
Ant	Nest in soil and burrow	Leaves, seeds and insects	Walk	Has six legs
Cow	Shed, grassy fields	Grasses, leaves	Walk	Has horns; chews cud
Squirrel	Tree	Fruits, nuts, seeds	Run and climb	Bushy tail
Fish	Water	Small plants and insects	Swim	Has fins

What are the similarities and differences among the animals that you have observed?

All animals need food and move from place to place.

Some live on land, some on trees and some in water. Frogs live on land as well as in water. They eat different kinds of food and move in different ways.

2.2Let us appreciate: How many different plants and animals did the class draw? Do you think there may be many more varieties?

The class drew many different plants and animals.

Yes. There are many more varieties of plants and animals than those drawn on the board. This variety is called biodiversity.

Trees give food and shelter to birds. Can you think of more examples which show that plants and animals depend on each other?

Bees and butterflies get nectar from flowers. They help flowers to form fruits and seeds.
Birds and animals eat fruits and spread the seeds to new places.
Animal dung and dead animals make the soil fertile for plants.

2.4Fill in your observations in Table 2.3 (grouping plants based on height and nature of stem).

Plant	Height	Stem	Branches	Group
Mango	Tall	Brown, hard, thick	Higher up on the stem	Tree
Neem	Tall	Brown, hard, thick	Higher up on the stem	Tree
Rose	Medium	Brown, hard, thin	Close to the ground	Shrub
Hibiscus	Medium	Brown, hard, thin	Close to the ground	Shrub
Tomato	Short	Green, tender, thin	Close to the ground	Herb
Mint (pudina)	Short	Green, tender, thin	Close to the ground	Herb

What differences do you observe among herbs, shrubs and trees?

Trees are tall. They have hard, thick, brown and woody stems. Branches start higher up on the stem. Example: mango.
Shrubs are of medium height. They have many hard but thin stems. Branches start close to the ground. Example: rose.
Herbs are small. They have soft and green stems. Example: tomato.

2.7Record the type of leaf venation and type of root of some plants in Table 2.4.

Plant	Leaf venation	Type of root
Lemongrass	Parallel	Fibrous
Marigold	Reticulate	Taproot
Sadabahar	Reticulate	Taproot
Wheat	Parallel	Fibrous
Mustard	Reticulate	Taproot

Relation: Generally, plants with reticulate venation have taproots. Plants with parallel venation have fibrous roots.

2.8Observe soaked chickpea and maize seeds. Are they similar or different?

They are different. A chickpea seed splits into two parts. Each part is a cotyledon. So chickpea is a dicot.

A maize seed has a single cotyledon. So maize is a monocot.

Dicot plants have reticulate venation and taproots. Monocot plants have parallel venation and fibrous roots.

2.9Note the ways in which animals move and the body parts used for movement (Table 2.5).

Animal	Type of movement	Body parts used
Ant	Walks	Legs
Goat	Walks and jumps	Legs
Pigeon	Walks and flies	Legs and wings
Housefly	Walks and flies	Legs and wings
Fish	Swims	Fins and tail
Snake	Crawls	Whole body (muscles)
Frog	Jumps and swims	Legs
Earthworm	Crawls	Whole body (muscles)

Conclusion: Different animals move in different ways. They use different body parts like legs, wings and fins to move.

2.10List the plants and animals found in different surroundings (Table 2.6).

Desert	Mountains	Ocean	Forest
Camel	Deodar tree	Fish	Lion
Cactus	Yak	Whale	Tiger
Desert lizard	Rhododendron	Dolphin	Elephant
Khejri tree	Snow leopard	Seaweed	Teak tree

Plants and animals found in one kind of region are different from those found in another region.

What are the differences between the camel of the hot desert and the camel of the cold desert?

The camel of the hot desert (Rajasthan) has long legs with wide hooves. These help it walk on sand without sinking. It has one hump.
The camel of the cold desert (Ladakh) has shorter legs. These help it walk in mountains. It has two humps and long hair from head to neck to survive the cold.

What other features can help camels to survive in the desert?

Camels excrete small amounts of urine. Their dung is dry and they do not sweat. So they lose very little water and can live for many days without drinking water.

Let us enhance our learning

1Here are two types of seeds. What differences do you find among the roots and leaf venation of their plants? (a) Wheat (b) Kidney beans

	Wheat	Kidney beans
Type of seed	Monocot	Dicot
Type of root	Fibrous roots	Taproot
Leaf venation	Parallel	Reticulate

2Group the animals based on their habitats. A: aquatic, B: terrestrial, C: both habitats. (Horse, Dolphin, Frog, Sheep, Crocodile, Squirrel, Whale, Earthworm, Pigeon, Tortoise)

A (Aquatic): Dolphin, Whale

B (Terrestrial): Horse, Sheep, Squirrel, Earthworm, Pigeon, Tortoise

C (Both water and land): Frog, Crocodile

A tortoise lives on land. Its relative, the turtle, lives in water. Some books place tortoise in C. Follow what your teacher says.

3Manu’s mother told him that radish is a kind of root. Examine a radish and write what type of root it is. What type of venation would you observe in the leaves of radish plant?

Radish is a taproot. Its main root becomes thick because it stores food.

Plants with taproots have reticulate venation. So radish leaves have reticulate venation.

4Look 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?

Similarities: Both have four legs, hooves and horns. Both eat grass and leaves.

Differences:

The mountain goat has thick, long white hair. The plains goat has short hair.
The mountain goat has strong legs and hooves for climbing rocky slopes.

Reasons: Mountains are very cold. Thick hair keeps the mountain goat warm. Strong legs and hooves help it climb steep rocks. These features are adaptations to its habitat.

5Group 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.

Feature: Whether they give birth to young ones or lay eggs.

Give birth to young ones	Lay eggs
Cow, bat, whale	Cockroach, pigeon, tortoise, fish, grasshopper, lizard

You can also group them by presence of backbone. Cockroach and grasshopper have no backbone. All others have a backbone.

6As forests are being cut down to meet various needs, how can this affect our surroundings? How do you think we can address this challenge?

Effects:

Animals and birds lose their homes and food. Biodiversity is lost.
Soil gets washed away by rain.
Air becomes polluted and the surroundings become hotter.
Rainfall may reduce. Floods and droughts may increase.

Ways to address it:

Plant more trees. Celebrate Van Mahotsav.
Use paper and wood carefully. Reuse and recycle.
Protect forests and sacred groves.
Spread awareness about saving forests.

7Analyse the flowchart. What can be examples of ‘A’ and ‘B’?

A has leaves with reticulate venation. Examples: mango, hibiscus, neem, mustard, chickpea.

B has leaves but without reticulate venation (parallel venation). Examples: grass, wheat, maize, banana.

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

How tall is the hibiscus plant?
Is its stem hard and woody, or soft and green?
Is its stem thick like a tree or thin?
Do its branches start close to the ground or higher up on the stem?

9Find out examples of plants for each group. Group A: Dicot, Taproot. Group B: Monocot, Fibrous roots.

Group	Examples
A (Dicot, taproot)	Mustard, chickpea, bean, mango, hibiscus
B (Monocot, fibrous roots)	Wheat, maize, rice, grass, banana

(a) Plants of group A have reticulate venation in their leaves and two cotyledons in their seeds.

(b) Plants of group B have parallel venation in their leaves and one cotyledon in their seeds.

10Observe the labelled part of a duck. 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?

A duck has webbed feet. Its toes are joined by a thin skin. A pigeon has separate toes.

Webbed feet work like paddles. They help the duck to swim in water.

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