Diversity in the Living World

The story of diversity

A long, long time ago, Earth was a silent, barren rock floating in the vastness of space. However, over millions of years, something magical happened — life began. At first, it was just simple, tiny creatures in the oceans. They had no eyes, no brains, just a way to survive. But nature is a brilliant artist, always experimenting. Slowly, these little organisms began to change. Some learned to use sunlight for energy — the earliest plants. Others became better at moving and hunting — the early animals. As time passed, life exploded into a beautiful mosaic of diversity. In the Forest, A huge elephant trumpets proudly, while a tiny ant scurries beneath its feet. Both are animals, yet they live very different lives. Trees reach for the sun, while moss quietly carpets the ground. In the Ocean, colourful fish dart between coral reefs, while jellyfish float. In the Desert, a cactus stands strong without water, storing every precious drop. A camel strolls through the heat, its hump full of energy reserves. This is diversity in living organisms — the variety of life that exists everywhere: in the sky, under the soil, on icy mountains, and even inside your own body.

Scientists classify this enormous variety using a system called taxonomy, dividing organisms into groups like kingdoms, phyla, classes, and more — from the broadest categories to the most specific. It helps us understand how different forms of life are related and how they evolved. If biodiversity is lost, crops may fail and diseases can spread faster. Ecosystems may collapse leading to climate change may get worse.

Importance of Diversity in Living Organisms

Diversity in living organisms — also known as biodiversity — is vital for the survival of life on Earth.

• Diversity maintains Balance in Nature as every organism plays a unique role in the ecosystem: Plants make oxygen and food through photosynthesis. Herbivores eat plants. Carnivores eat herbivores. Decomposers like fungi and bacteria break down dead organisms and recycle nutrients. If one species disappears, it can affect many others, like dominoes falling.

• Diversity provides Food and Resources required for the survival as we get food like fruits, vegetables, meat, and milk from various living organisms. Trees provide wood, cotton plants give us fiber for clothes, and bees give us honey. Many medicines are made from plants and microorganisms.

• Diversity Supports Clean Air, Water, and Soil . Forests purify the air and bring rain and wetlands filter water and prevent floods. Earthworms and microbes make soil fertile. Biodiversity keeps our environment healthy.

• Diversity assists in studying diverse organisms for scientists:

• Diversity supports adaptation and survival as more diversity means more chances for life to adapt to changes. If the climate changes, some species may survive better than others may. This helps ecosystems stay strong and recover after disasters.

Grouping Plants and Animals based on diversity

Classifying plants and animals is very important, as there is much confusion due to the similarities. For example, leopard, tiger, cheetah looks very similar but they are different in many ways. Classification of animals and plants is based on the similarities or differences between the individuals. Grouping plants and animals help us to understand the diversity, making it easier to identify, compare, and classify them. Understanding the diversity provides a opportunity to learn the evolutionary relationships and the organisms role in the ecosystem. Plants are grouped based on their height, stem structure, leaf types, root types, branches, seed structure, and the type of fruits or flowers they yield.

• Plants based on height are further classified into herbs, shrubs, climbers and trees based on their height and types of stem. Herbsare small plants with soft and green stems. An example of an herb is the tomato plant. Trees grow very tall and have hard, thick, brown, and woody stems. Mango, guava, pine etc are some examples. Shrubs are not too small but not very tall as trees. Their branches begin from very close to the ground. Climbers have weak stems that generally need support to climb and grow, while Creepers are plants that grow by creeping along the ground.
• 2. Plants based on Stems are classified as hard stemmed and soft stemmed plants. In trees and shrubs, the stem is strong and woody to survive in different weather conditions but some smaller plants have soft and green stems. For example; flowers, herbs, and vegetables.
• Plants based on branches is classified as plants that are close to the Ground and plants that are far from ground.
• Plants based on venation are classified as parallel and reticulate venation types. The pattern of distribution of thin network of veins is called venation. Reticulate Venation shows veins that form a network, common in dicot plants like hibiscus and peepal while parallel Venation shows veins that run parallel to each other, common in monocot plants like grass and wheat. In plants, there is a strong relationship between the type of leaf venation and the type of root system. Here is a simple explanation:

Leaf Venation Type	Root Type	Examples
Reticulate Venation	Tap Root System	Mango, Rose, Sunflower
Parallel Venation	Fibrous Root System	Grass, Wheat, Maize

• Plants based on root types are classified as taproots and fibrous roots. Taproots have one main root that grows straight down with smaller side roots (e.g., mustard, hibiscus). Fibrous roots consist of thin, branching roots that spread out from the base of the stem (e.g., grass).
• Plants based on seeds are classified as monocots and dicots. Dicots have seeds with two cotyledons (e.g., groundnut, green peas), while monocots have a single cotyledon (e.g., maize).

Grouping Animals

Grouping animals helps us understand and protect biodiversity. Animals can be classified based on food habits, size, movement, habitat, and body structure (presence or absence of backbone).

• Based on movement: Animals may fly (birds), run (horses), crawl (snakes), hop (frogs), or swim (fish).
• Based on food habits: Herbivores eat plants, carnivores eat meat, and omnivores eat both.
• Based on backbone: Animals with a backbone are vertebrates (e.g., humans), and those without are invertebrates (e.g., earthworms).
• Based on habitat: Animals may live on land, in water, trees, air, deserts, or underground.

Types of Animal Movements

Animal	Type of Movement	Body Part Involved
Human	Walking, Running	Legs, Feet, Muscles
Fish	Swimming	Fins, Tail, Body Muscles
Bird	Flying	Wings (modified forelimbs)
Snake	Slithering	Body Muscles, Scales
Earthworm	Crawling	Body Segments, Bristles (setae)
Snail	Gliding	Muscular Foot
Insects	Walking / Flying	Legs, Wings
Frog	Jumping, Swimming	Hind Legs, Webbed Feet
Horse	Walking, Running, Galloping	Legs, Hooves
Octopus	Crawling, Jet Propulsion	Arms (tentacles), Siphon

Habitats of Animals

Habitat	Type of Animals	Examples
Terrestrial	Live on land	Lion, Elephant, Tiger, Dog, Ant
Aquatic	Live in water	Fish, Whale, Dolphin, Shark, Octopus
Amphibians	Live on land and water	Frog, Toad, Salamander
Aerial	Mostly in air	Eagle, Sparrow, Bat, Butterfly
Arboreal	Live in trees	Monkey, Sloth, Chameleon, Koala
Desert	Hot, dry areas	Camel, Lizard, Scorpion, Desert Fox
Polar	Cold, snowy regions	Polar Bear, Penguin, Arctic Fox, Seal
Underground	Live below ground	Mole, Earthworm, Ant, Rabbit

Feeding Habits of Animals

Feeding Type	What They Eat	Examples
Herbivores	Only plants	Cow, Goat, Deer, Elephant, Horse
Carnivores	Only meat	Lion, Tiger, Wolf, Eagle, Snake
Omnivores	Plants and animals	Human, Bear, Pig, Crow, Dog
Scavengers	Dead animals	Vulture, Hyena, Jackal, Crow
Parasites	Host’s body fluids	Leech, Tick, Tapeworm, Lice
Detritivores	Decomposing matter	Earthworm, Dung Beetle
Filter Feeders	Tiny particles in water	Whale, Sponge, Oyster, Flamingo

Plants and Animals in Different Surroundings

All plants and animals live in a place with their surroundings. The place where they live is called a habitat. A habitat is the natural environment where a plant or animal lives, providing the necessary conditions for survival, such as food, water, shelter, and space. Different plants and animals are adapted to live in specific habitats that suit their needs.

Types of Habitats

Surrounding / Habitat	Plant Features	Animal Features	Examples
Deserts	- Small/spiny leaves to reduce water loss - Thick stems for water storage (succulents) - Long roots to reach water	- Can survive with little water - Often active at night (nocturnal) - Fat storage in body	Plants: Cactus, Acacia Animals: Camel, Lizard, Scorpion
Mountains	- Needle-shaped leaves - Sloping branches - Evergreen to withstand snow	- Thick fur for warmth - Hooves or claws for climbing	Plants: Pine, Fir Animals: Snow Leopard, Yak, Mountain Goat
Plains / Grasslands	- Moderate-sized leaves - Deep roots - Can tolerate grazing	- Fast runners - Keen senses for predators/prey	Plants: Grasses, Wheat Animals: Lion, Deer, Zebra
Water (Aquatic)	- Floating leaves - Air spaces in tissues - Flexible stems	- Gills or fins - Streamlined bodies	Plants: Lotus, Hydrilla Animals: Fish, Frog, Octopus
Rainforests	- Large, broad leaves for capturing sunlight - Drip tips to shed water	- Bright colors - Good climbers or fliers - Loud calls	Plants: Rubber tree, Orchids Animals: Monkey, Parrot, Jaguar
Polar Regions	- Very few plants (mosses, lichens) - Grow during short summer	- Thick fur and fat (blubber) - White color for camouflage	Plants: Moss, Algae Animals: Polar Bear, Penguin, Seal
Aquariums / Zoos	- Artificial plants or controlled environments	- Kept in enclosures with climate control and food supply	Plants: Water plants in aquariums Animals: Fish, Lions, Elephants

Adaptations

Adaptations are special features or behaviours that help plants and animals survive in their environments.

Animals and plants need adaptations to survive, grow, and reproduce in their specific environments. Different plants and animals have a variety of special modifications to adjust to their environment. Every adaptation has a specific reason . The following table describes the adaptation of different plants and animals that live in different surroundings.

Habitat	Plant Adaptations	Animal Adaptations
Desert	- Thick stems to store water - Spines instead of leaves to reduce water loss - Deep roots	- Hump in camels for fat storage - Long eyelashes - Can survive without water for days
Aquatic	- Floating leaves with waxy coating - Hollow stems - No rigid stems	- Fins and gills for swimming and breathing - Streamlined body - Webbed feet (e.g., duck)
Mountain	- Needle-like leaves - Sloping branches to shed snow - Evergreen leaves	- Thick fur for warmth - Strong hooves for climbing - Small ears to prevent heat loss
Rainforest	- Broad leaves to capture sunlight - Drip tips to shed water	- Bright colors for communication - Strong limbs for climbing - Camouflage to hide from predators
Cold/Polar	- Few or no plants (mostly mosses and lichens)	- Thick fur or blubber for warmth - White fur for camouflage - Compact body to conserve heat
Grassland	- Deep roots to access water - Narrow leaves to reduce water loss	- Fast runners to escape predators - Sharp teeth or flat molars depending on diet
Swamp/Marsh	- Aerial roots (breathing roots) - Salt-filtering systems (in mangroves)	- Amphibians like frogs with moist skin - Webbed feet for swimming

Protecting Biodiversity

To protect biodiversity, we need to take care of our environment. This includes not polluting our surroundings, conserving natural habitats, and using resources sustainably. By protecting biodiversity, we ensure that all living things can thrive. The methods to preserve and protect the diversity is explained below.

Method	Details
1. Conservation of Habitats	Protect forests, wetlands, oceans, and other natural areas from destruction.
2. Wildlife Protection Laws	Enforce laws that ban hunting, poaching, and illegal trade of animals.
3. Reducing Pollution	Minimize use of harmful chemicals, plastics, and waste that harm ecosystems.
4. Afforestation	Plant more trees to restore natural habitats.
5. Creating National Parks	Set up protected areas where species can live safely.
6. Educating People	Raise awareness about the importance of biodiversity in schools and communities.
7. Sustainable Use of Resources	Use natural resources wisely so they last longer (e.g., water, wood, fuel).

Chapter Exercises

Let us enhance our learning

Question 1. Here are two types of seeds. What differences do you find among the roots and leaf venation of their plants?
Answer: Wheat plants have fibrous roots and leaves with parallel venation. The Kidney bean plants have taproots and leaves with reticulate venation.

Question 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.
Answer: 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 .

Question 3. Manus 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?
Answer:Tap of Root is tap root and the type of venation is Reticulate.

Question 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?
Answer:Similarities:

Both are goats and belong to the same family.

Both are herbivores because they eat plants including roots, stems, leaves etc.

Differences:

Mountain Goats has thick, long fur to protect against cold mountain temperatures but goat in plains has shorter fur suited for warmer climates.

Mountain Goats are generally stockier and more muscular, adapted for climbing rocky terrains Plains Goats are generally leaner build suitable for flat, open areas.

Mountain Goats have specialised hooves with a rough texture for better grip on rocky surfaces. while plain goats have hooves more suited for walking on flat, grassy lands.

Question 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.
Question 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?
Answer: 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.

• Replanting of trees and, putting a ban on cutting of trees.
• Implementing regulations and laws to address the severity of cutting down the forest.

Question7.Analyse the flow chart. What can be examples of A & B.
Answer: Option A is, the plants having leaves with reticulate venation have tap roots and the option B IS THE The plants not having leaves with reticulate venation have fibrous roots.

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

• What is the nature of its stem?
• What is the height of the Gudhal (hibiscus) plant?
• Is the stem of the Gudhal plant woody?
  
  Question 9. Based on the information in the table, find out examples of these plants for each group. Group Type of seed Type of root Example A Dicot Taproot ? B Monocot Fibrous root ? (a) What other similarity do plants of group A have? (b) What other similarity do plants of group B have?
  Answer: Group Type of seed Type of root Example A Dicot Taproot Gram, beans, bottle ground, mango B Monocot Fibrous root Wheat, rice, maize (a) Plants of group A have reticulate venation. (b) Plants of group B have parallel venation.
  
  Question 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?
  Answer:Ducks have webbed feet, which are different from the feet of the other birds like pigeon. Ducks use their webbed feet like paddles to provide more surface to push against the water, which helps them to move through the water.