---
title: "Classifying Organisms"
description: "Compare broad biological groups, including plants, animals and fungi, using shared characteristics. Recognise that micro-organism describes very small organisms and can overlap biological groups."
canonical: https://lightmysky.com/learn/science/classifying-organisms-mt_IY3KwGLZgk
source: https://lightmysky.com/learn/science/classifying-organisms-mt_IY3KwGLZgk.md
retrieved: 2026-11-12
---

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# Classifying Organisms

Compare broad biological groups, including plants, animals and fungi, using shared characteristics. Recognise that micro-organism describes very small organisms and can overlap biological groups.

Subject: Science · Area: Ecosystems & Habitats · Ages 10 to 11
Page: https://lightmysky.com/learn/science/classifying-organisms-mt_IY3KwGLZgk

## Ready when they can

- Name plants, animals and fungi as broad biological groups, and explain that these are not a complete list of all life
- Compare characteristics such as food methods, and explain why movement or size alone does not identify a biological group
- Give examples of plants, animals, fungi and micro-organisms, including bacteria and microscopic fungi such as yeast

## Lesson: The Big Groups of Living Things

Scientists compare shared characteristics to place organisms in biological groups. Plants, animals and fungi are examples, not a complete list of all life. Micro-organism describes very small organisms. It is a size description that can overlap biological groups.

Most plants make food using sunlight. Grass, daisies and ferns are examples. Animals obtain food by eating organisms or material from them. Birds, snails and grasshoppers are animals. A grasshopper can eat grass: the grass makes food using sunlight, while the grasshopper eats it. Many animals move to find food, but movement alone does not identify an animal.

*(drawing: This describes how most plants obtain food. It is not a test that identifies every unknown organism.)*

**Example.** An oak tree and a cactus are plants that make food using sunlight. A rabbit eats grass, and a seagull eats food it finds. Both are animals. A rock is nonliving. Compare known examples and several characteristics instead of deciding from colour or movement alone.

Mushrooms, moulds and yeasts are fungi. Fungi absorb nutrients from their surroundings and do not make food using sunlight. Many break down dead material; others obtain nutrients from living things. Bread mould can break down bread. A fungus on dead wood can get nutrients from that wood. Compare it with a daisy: the daisy makes food using sunlight; this fungus absorbs nutrients from wood. Their shared stillness does not make their food methods the same.

*(drawing: These descriptions all refer to the same organism. Yeast does not change groups as you read across.)*

Micro-organisms are very small organisms, usually studied with a microscope. A typical individual bacterium needs a microscope to be seen clearly. Bacteria are living things, but they are neither plants nor animals. Some bacteria move. Yeasts are microscopic fungi, and some animals are microscopic too. A microscopic animal is still an animal.

Size, movement and food provide useful evidence, but no single clue sorts every organism. Some micro-organisms move or use sunlight. If an unknown pond organism moves, eats and is microscopic, you can describe its small size. You need more evidence to settle its biological group.

*(drawing: Keep an observation, such as microscopic size, separate from a conclusion about biological group.)*

Compare specified individuals when ordering sizes. A seedling and a full-grown tree can differ greatly. Use the stated size relationships: if one organism is larger than another, place it earlier in a biggest-to-smallest list. A microscopic individual comes after much larger examples that you can see without a microscope.

**Recap.** Compare shared characteristics to identify biological groups. Micro-organism describes small size and can overlap groups such as fungi and animals.

*The lesson, questions and flashcards were written for this dataset.*

## Practice

24 questions on this page, each with its working shown.

## Optional connections

- [Classification Keys](https://lightmysky.com/learn/science/classification-keys-mt_brgde1Vx0P)

## Opens up

- [Evidence-Based Classification](https://lightmysky.com/learn/science/evidence-based-classification-mt_B8lX8OCzGu)
- [How Natural Selection Works](https://lightmysky.com/learn/science/how-natural-selection-works-mt_FuVEZ1Ac9s)