Science
What are living things?
Quick answer
Living things are organisms that grow, feed, get rid of waste, sense the world and reproduce. Plants, animals, fungi and bacteria are all alive.
In one sentence
A living thing is anything that is alive: it grows, feeds, gets rid of waste, notices the world around it and can make more living things like itself.
Explained
Scientists use a checklist to decide if something is alive. Many classrooms remember it as MRS GREN:
- Movement — all living things move in some way. Plants move slowly, turning their leaves towards light.
- Respiration — releasing energy from food.
- Sensitivity — noticing changes, such as light, heat or touch.
- Growth — getting bigger or developing.
- Reproduction — making young, seeds or spores.
- Excretion — getting rid of waste.
- Nutrition — taking in or making food.
Something is living only if it does all seven at some point in its life. A car moves, uses fuel and gives out waste gas, but it cannot grow or make baby cars. So it is not alive.
Every living thing is made of tiny building blocks called cells. Some, like bacteria, are just one cell. You are made of trillions.
Examples
| Thing | Living, once living or never living? |
|---|---|
| Oak tree | Living |
| Ladybird | Living |
| Mould on bread | Living (a fungus) |
| Paper | Once living (made from trees) |
| Wool jumper | Once living (from a sheep's fleece) |
| Rock | Never living |
| Water | Never living |
tree
ladybird
mushroom
rock
Common mistakes
- "Plants aren't alive because they don't move." They do move, just slowly. Sunflowers turn, roots push down and seeds sprout. Plants carry out all seven life processes.
- "If it moves, it's alive." Wind, rivers and robots move but are not alive. Check the whole list, not just one process.
- "Dead means never living." A fallen leaf is dead, which means it was alive. "Never living" is for things like stones, metal and glass.
- "Viruses are definitely alive." Scientists still debate this. Viruses can only reproduce inside other cells, so many biologists say they are not fully alive.
Quick quiz
Living things
Check what you know with 4 quick questions.
Question 1 of 4
Which of these is a living thing?
Practise it
Try it
Sort objects around the house into three piles: living, once living and never living. Then see where living things make their homes in habitats.
Print science activities for kids
For grown-ups
Related topics
Habitats
A habitat is the natural home of a living thing, where it finds the food, water, shelter and space it needs to survive.
Cells
A cell is the smallest living unit. Every living thing is made of one or more cells, each with a membrane, cytoplasm and, in plants and animals, a nucleus that controls it.
Life cycles
A life cycle is the series of changes a living thing goes through from the start of its life to becoming an adult that can produce young, so the cycle begins again.
Food chains
A food chain shows who eats whom in nature, starting with a plant that makes its own food and following the energy as it passes from one living thing to the next.
Fossils
Fossils are the preserved remains or traces of plants and animals that lived long ago, usually found in sedimentary rock. They help scientists learn how life on Earth has changed.
Parts of a plant
The main parts of a flowering plant are the roots, stem, leaves and flowers. Each part has a job, from soaking up water to making food and producing seeds.