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Students learn how to tell if something is a living thing by looking for signs of life like breathing and growing.
Look at your favorite toy. Now look at a pet or a plant. One of them can grow and breathe all on its own—do you know which one and why?
Living things are amazing! To stay alive, they need energy. They get this energy by breathing air and eating food or drinking water. Think about yourself: you eat breakfast to have energy to play! A plant 'breathes' through tiny holes in its leaves and 'drinks' water through its roots. If something doesn't need to eat, drink, or breathe, it is non-living, like a rock or a swing set.
Let's look at a puppy and a toy dog: 1. The puppy breathes air; the toy does not. 2. The puppy needs bowl of water to stay hydrated; the toy stays dry. 3. The puppy is a living thing!
Quick Check
Does a bicycle need to breathe air to move down the street?
Answer
No, a bicycle is non-living and does not breathe.
Living things don't stay the same size forever. They grow and change. This is part of their life cycle. You were once a tiny baby, but now you are a big grader! A tiny acorn can grow into a giant oak tree that is feet tall. Non-living things, like your bed or your shoes, stay the same size unless they break or someone changes them.
Watch how a sunflower changes: 1. It starts as tiny seed in the dirt. 2. It grows roots to find water. 3. It grows a stem and leaves to reach the sun. 4. It turns into a tall, bright flower!
Quick Check
If you have a small rock and wait years, will it grow into a giant mountain on its own?
Answer
No, because a rock is non-living and cannot grow.
Living things react to what is happening around them. If you touch a turtle, it might pull its head into its shell to stay safe. This is called a response. Plants react too! They turn their leaves toward the sun to get more light. Non-living things only move if someone pushes or pulls them, like a ball rolling because you kicked it.
Think about a robot. 1. It moves around the room. 2. It 'drinks' electricity from a battery for energy. 3. But is it alive? No! A robot cannot grow bigger on its own, and it cannot have 'baby' robots. It is a machine.
Which of these is a living thing?
What do living things need to stay alive?
A teddy bear is a living thing because it has soft fur.
Review Tomorrow
Tomorrow morning, look around your room and try to find living thing and non-living thing.
Practice Activity
Go for a 'Life Walk' in a park or garden. Count how many living things you can see moving or growing!