What this chapter is about
Look around you — dogs, cats, sparrows, mango trees, grass, mushrooms, fish in a pond. The world is full of living things, and they are all different from each other. This variety of living things is called biodiversity. Biodiversity means the many different kinds of plants, animals and tiny organisms found on Earth.
In this chapter, you will learn how scientists sort living things into groups so they are easier to study. This sorting is called classification. You will also discover what makes a plant different from an animal, and what makes a cat different from a fish. Understanding these differences helps us protect nature and care for all living beings.
By the end of this chapter, you should be able to name the major groups of living things, tell how they differ, and give examples from your daily life.
Key ideas
- Living things are organisms that can grow, breathe, eat, reproduce and respond to their surroundings. Non-living things cannot do these.
- Biodiversity is the variety of all living organisms on Earth — big or small, on land or in water.
- Classification is the method of putting living things into groups based on their similarities and differences.
- Scientists have sorted all living things into five main groups called kingdoms: Animals, Plants, Fungi, Protista (tiny single-celled creatures) and Monera (bacteria).
- Animals cannot make their own food; they eat plants or other animals. Plants make their own food using sunlight.
- Vertebrates are animals with a backbone (like fish, frogs, birds and humans). Invertebrates have no backbone (like insects, worms and snails).
- Plants are grouped as flowering plants (which produce flowers and fruits) and non-flowering plants (like ferns and mosses).
- Every organism has a habitat — the place where it lives and finds food, water and shelter.
Formulas and facts to remember
1. Biodiversity – the variety of living things found in a place or on the whole Earth. 2. Classification – the process of sorting living things into groups based on shared features. 3. Five Kingdoms – Animals, Plants, Fungi, Protista, Monera. 4. Vertebrate – an animal with a backbone (examples: sparrow, cat, fish). 5. Invertebrate – an animal without a backbone (examples: butterfly, earthworm, spider). 6. Autotroph – an organism that makes its own food (all green plants). 7. Heterotroph – an organism that cannot make its own food and eats other organisms (all animals, fungi). 8. Habitat – the natural home of an organism where it gets everything it needs to survive.
Worked examples
Example 1: Sorting animals into vertebrates and invertebrates
Rahul sees these animals near his house: a crow, a grasshopper, a stray dog, a snail and a garden lizard. Sort them into vertebrates and invertebrates.
Step 1: Ask — does the animal have a backbone?
- Crow – yes, it has a backbone → vertebrate
- Grasshopper – no backbone → invertebrate
- Dog – yes → vertebrate
- Snail – no backbone → invertebrate
- Lizard – yes → vertebrate
Answer: Vertebrates — crow, dog, lizard. Invertebrates — grasshopper, snail.
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Example 2: Identifying the kingdom
Meena found a mushroom growing on a damp log in her garden. Is it a plant or something else?
Step 1: Check if it is green and makes its own food. Mushrooms are not green. They do not have leaves and cannot make food using sunlight.
Step 2: Mushrooms get food by absorbing nutrients from dead matter. They belong to the kingdom Fungi, not Plants.
Answer: A mushroom is a fungus.
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Example 3: Flowering or non-flowering?
Ajay notices a mango tree and a fern in his school garden. Which is a flowering plant?
Step 1: Mango trees produce flowers that later become mango fruits.
Step 2: Ferns never produce flowers. They reproduce using tiny spores.
Answer: Mango tree — flowering plant. Fern — non-flowering plant.
Common mistakes
- Thinking all animals are vertebrates → Many animals like insects, earthworms and jellyfish have no backbone; they are invertebrates.
- Believing mushrooms are plants because they grow in soil → Mushrooms do not make food using sunlight; they are fungi.
- Confusing habitat with the animal itself → Habitat is the place (pond, forest, desert), not the organism.
- Assuming all living things need sunlight to survive → Animals do not make their own food from sunlight; only green plants do.
- Thinking classification means ranking from best to worst → Classification is about grouping by features, not by importance.
Quick revision
- Biodiversity = variety of living organisms.
- Classification helps us study millions of species by putting them in groups.
- Five kingdoms: Animals, Plants, Fungi, Protista, Monera.
- Vertebrates have a backbone; invertebrates do not.
- Plants make their own food; animals cannot.
- Every organism lives in a habitat suited to its needs.