Living, Once-Living and Non-Living Things — Answers
Answer sheet with model answers and success criteria for the 3rd Grade living things & life cycles worksheet.
Success TutoringWorksheetsAnswer sheet3rd Grade · Science · Living Things & Life CyclesLiving, Once-Living and Non-Living Things — Answers
Part A: The signs of life
Read the passage. Then circle the best answer.
Scientists say something is living if it does all of these things: Moves, Respires (breathes or uses air), Senses, Grows, Reproduces (makes young or seeds), gets rid of Excretion (waste) and needs Nutrition (food). The first letters spell MRS GREN.
Plants are living too. They move slowly (turning towards light), grow, make seeds and make their own food.
Once-living things were alive but are not now, or came from a living thing. Wood, paper, cotton, a fallen leaf and a feather are once-living.
Non-living things were never alive, like rocks, metal, glass, water and air. Some non-living things show one or two signs of life — a car moves and fire grows — but they do not show all seven.
- Aa pebble
- Ba wooden spoon
- Ca glass marble
- Da metal key
Answer: a wooden spoon
Wood came from a tree that was once alive, so a wooden spoon is once-living.
- Aa feather
- Ban apple
- Ca rock
- Da leaf
Answer: a rock
A rock was never alive. Feathers, apples and leaves came from living things.
- ANo, because it does not move.
- BYes, because it can grow into a plant when it gets water and warmth.
- CNo, because it is small.
- DYes, because it is hard.
Answer: Yes, because it can grow into a plant when it gets water and warmth.
A seed is alive but resting. Given water and warmth it grows.
- AIt is too hot.
- BIt cannot reproduce, sense or take in food like living things.
- CIt is orange.
- DIt only happens at night.
Answer: It cannot reproduce, sense or take in food like living things.
Fire shows some signs, but not all of them. Living things show all seven.
- AThey can walk.
- BThey need food or nutrition.
- CThey have fur.
- DThey live in water.
Answer: They need food or nutrition.
All living things need nutrition. Plants make their own food; animals eat other living things.
Part B: Sort and explain
- a mushroom growing in the garden
- a paper bag
- a plastic bottle
- living
- non-living
- once-living
Answer: a mushroom growing in the garden → living; a paper bag → once-living; a plastic bottle → non-living
Answer: grows
Also accept: growth.
Answer: once-living
Answer: No. A robot cannot grow, reproduce or take in food by itself, so it does not show all the signs of life.
Part C: True or false?
Write True or False.
Answer: True
Plants grow, reproduce, need nutrition and respond to light.
Answer: False
The wood came from a tree, so the table is once-living.
Answer: True
Showing only one or two signs, like a moving car, is not enough.
Answer: False
Water was never alive; it is non-living, even though living things need it.
Part D: Thinking scientifically: use the evidence
Model answer: I disagree. The leaf is once-living. It was part of a living tree, but now it has fallen off. It can no longer grow, take in nutrition or respire, so it is not living any more.
Success criteria:
- Classifies the leaf as once-living
- Uses at least two MRS GREN signs as evidence
Marking tips
- Give credit for correct method even when the final answer slips — the working shows where the thinking went right.
- For open-ended tasks, use the success criteria as a checklist rather than looking for one "right" answer.
- Celebrate what went well first, then pick one thing to work on next.
Great work. Here's what to try next: