Alive or not alive?
Look around you. A dog, a tree and a spider are living things. A rock, a chair and a toy car are nonliving things. How can we tell the difference?
Living things all do some important jobs. Nonliving things don’t.
What living things do
| Living things… | Example |
|---|---|
| grow and change | A kitten grows into a cat. A seed grows into a sunflower. |
| need food and water | A rabbit eats grass and drinks water. A plant soaks up water through its roots. |
| need air | You breathe air. Fish get air from the water through their gills. |
| use energy | A bird uses energy to fly. A plant uses energy from sunlight to make food. |
| respond to the world | A cat runs when a dog barks. A plant bends toward the light. |
| make more of their own kind | Ducks lay eggs that hatch into ducklings. |
The young of a living thing are called its offspring. Puppies are the offspring of dogs. Baby plants called seedlings are the offspring of plants.
Nonliving things
Nonliving things don’t grow, eat, breathe or have babies. A rock stays a rock. A teddy bear doesn’t get hungry. A ball doesn’t grow into a bigger ball.
Some nonliving things move or change, which can be tricky!
- A car moves, but it doesn’t grow or have baby cars.
- Fire gets bigger and needs air, but it doesn’t eat food or make baby fires on purpose.
- Clouds grow and move, but they are just water drops in the sky.
To decide, check all the clues, not just one.
Once living
Some things used to be alive but aren’t anymore. We call them once living.
- A dry leaf on the ground
- A wooden table (wood comes from trees)
- A seashell (it was once the home of a sea animal)
- A cotton shirt (cotton comes from a plant)
Are plants alive?
Yes! Plants don’t walk or talk, but they are living things. They grow, they need water, air and sunlight, they use energy, and they make seeds that grow into new plants. They even respond, turning their leaves toward the Sun.
In the real world
Gardeners know plants are living, so they water them and give them sunlight. Pet owners know their pets need food, water and care. Scientists who explore other planets look for signs of living things by checking for growth, energy use and reproduction.
Common mistakes
- Thinking anything that moves is alive. Cars and wind move, but they are not alive.
- Thinking plants aren’t alive because they stay in one place.
- Forgetting about once-living things like wood and paper.
Try it yourself
Go on a walk outside or around your home.
- Find three living things.
- Find three nonliving things.
- Find one once-living thing.
- For each living thing, say one clue that shows it is alive.
Quick recap
- Living things grow, need food, water and air, use energy, respond and make more of their kind.
- Nonliving things don’t do these things.
- Some nonliving things move, so check all the clues.
- Once-living things used to be alive.
- Plants are living things too.