ACARA v9 CONTENT DESCRIPTION “compare characteristics of living and non-living things and examine the differences between the life cycles of plants and animals”
Builds on noticing the plants and animals around us. Here we ask a sharper question: what makes something a living thing at all, and how do living things grow and make young of their own?
What makes something living?
Living things share a few jobs that non-living things never do. They grow, they take in food and water, they can make young of their own, and most can move by themselves. A dog and a gum tree do these jobs; a rock and a drop of water do not. Looking for these jobs is how we tell a living thing from a non-living one.
The living-things checklist
Living things all do the same jobs. Tick each job this thing can do. Then look at how many ticks it gets.
A Dog truly does 4 of the 4 jobs. You have ticked 0. Something that does all four jobs is a living thing; a thing that does none of them, like a rock, is non-living. Switch the thing and tick again.
Living, non-living, and once-living
Some things are a little tricky. A wooden chair and a seashell are not alive, yet they are not quite the same as a rock. They came from living things, a tree and a sea animal, so we call them once-living. Sorting things into living, non-living and once-living helps us see where each one really belongs.
Living, non-living or once-living?
Some things were never alive. Some are alive now. Some were once part of a living thing. Place each item in a bin.
Where does the Butterfly go?
A living thing is alive right now. A non-living thing was never alive. An once-living thing, like wood or a shell, came from something that was once alive.
Plants grow in a cycle
A living thing does not just grow once and stop. A plant starts as a seed, sprouts, grows into a full plant, makes flowers, and the flowers make new seeds. Those seeds can grow into new plants, so the journey comes back to where it began. We call this repeating journey a life cycle.
A plant's life cycle
A plant grows in stages and then makes seeds of its own. Step forward to follow it all the way around.
Stage 1 of 5: Seed. A seed rests in the soil with a tiny plant packed inside. Because the last stage makes new seeds, the path bends back to the start. That is why we call it a cycle.
Animals grow in a cycle too
Animals have life cycles as well. A butterfly begins as an egg, hatches into a caterpillar, forms a chrysalis, and comes out as a butterfly that lays new eggs. The caterpillar looks nothing like the butterfly, but it is the same animal at a different stage of its cycle.
An animal's life cycle
A butterfly changes shape completely as it grows. Step forward to follow egg, caterpillar, chrysalis and butterfly.
Stage 1 of 5: Egg. A tiny egg is laid on a leaf. A caterpillar looks nothing like the butterfly it becomes, yet it is the same animal. Like the plant, the cycle returns to the start.
Comparing the two cycles
Plant and animal life cycles are alike in one big way and different in another. Both are loops: each one ends by making young that start the journey over. But the stages have different names, and an animal like a butterfly changes its whole shape, while a plant keeps the same body and adds flowers and seeds.
Two cycles side by side
A plant and an animal both travel a loop, but their stages are different. Step once to move both pointers together.
At step 1 the plant is at "Seed" and the animal is at "Egg". Both are loops that come back to where they began, but the stages have different names and the butterfly changes shape far more than the plant does.
Why this matters
Knowing what living things do, and how plants and animals grow through their cycles, helps us care for a garden, raise an animal, and understand the living world around us. Every plant and animal is somewhere on its own life cycle right now.
Quick self-check
1. Which list shows jobs that all living things do?
2. A wooden chair is best sorted as...
3. In the plant life cycle, what comes right after a seed sprouts?
4. In the butterfly life cycle, what comes between caterpillar and butterfly?
5. How are a plant cycle and an animal cycle alike?