Grade 3 · Unit 3: Living things

Living and non-living

Is a flame alive? Is a seed? How can you tell?

A cow moves, eats, breathes, grows and has calves – it is living.

What do living things do?

All living things do seven things. We call them the life processes. They move, breathe, sense, grow and reproduce. They also need food and get rid of waste.

A handy way to remember them is “MRS GREN”: Movement, Respiration (breathing), Sensing, Growth, Reproduction, Excretion (getting rid of waste) and Nutrition (food).

Plants are alive too

Plants do not walk, but they are living. They grow, make seeds and turn their leaves towards light. They take in air and water, and they make their own food.

Once alive or never alive?

A non-living thing does not do the life processes. Some things were once alive, like wood, cotton, paper and a dead leaf. Some things were never alive, like rocks, metal, glass and plastic.

A seed can seem dead for a long time, but it is alive. When it gets water and warmth, it germinates and grows.

Tricky ones

A fire moves, grows and needs air, but it is not alive. It cannot reproduce by itself, and it does not need food like living things. A car moves and needs fuel, but it does not grow or reproduce.

What I learnt