Primary 3 · Science · Biological sciences
Grouping living things
Students sort animals and plants into groups using observable features, such as birds with feathers, mammals with fur, and flowering and non-flowering plants.
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These lessons were written around Australian Curriculum strands and matched to Singapore levels by age (Primary 1 is the first year of primary school). They are not aligned to MOE syllabuses or the PSLE, so check them against the syllabus your child is working towards.
Learning goals
Learners will
- Sort animals into groups (mammals, birds, reptiles, amphibians, fish and insects) using features we can see.
- Sort plants into flowering and non-flowering groups.
- Use a simple yes/no key to identify a living thing's group.
Success looks like
- I can name the main feature of each animal group.
- I can say whether a plant is flowering or non-flowering and why.
- I can follow a yes/no key to sort a living thing.
The big idea
Scientists classify living things by putting those with the same features into groups. This makes it easier to study and talk about them.
Animals with a backbone are sorted into five main groups:
- Mammals have fur or hair and feed their babies milk. Examples: dogs, people, bats, whales.
- Birds have feathers, a beak and wings, and lay eggs with hard shells. Examples: eagles, penguins, chickens.
- Reptiles have dry, scaly skin. Most lay eggs on land. Examples: snakes, lizards, turtles.
- Amphibians have smooth, damp skin. Most start life in water and later live on land. Examples: frogs, toads.
- Fish live in water, breathe with gills and have fins. Most have scales. Examples: sharks, goldfish.
Many animals have no backbone. Insects are one group: they have six legs and three body parts. Spiders are not insects; they have eight legs and two body parts.
Plants can be sorted too. Flowering plants make flowers, and the flowers make seeds, often inside fruit. Grass, oak trees, roses and tomato plants all flower, even if some flowers are tiny.
Non-flowering plants never make flowers. Ferns and mosses make tiny spores instead of seeds. Pine trees and other conifers make seeds inside cones.
Worked examples
Is a whale a fish?
A whale lives in the sea and has fins. Which group does it belong to?
- Check the features: a whale breathes air with lungs, not gills.
- It has a few hairs (especially when young) and feeds its baby milk.
- Fur or hair and milk are mammal features.
Answer: A whale is a mammal, not a fish.
Using a yes/no key
Use the key to classify a lizard. 1. Does it have feathers? Yes → bird. No → go to 2. 2. Does it have fur or hair? Yes → mammal. No → go to 3. 3. Does it have dry, scaly skin? Yes → reptile. No → amphibian or fish.
- Question 1: does a lizard have feathers? No, go to 2.
- Question 2: does it have fur or hair? No, go to 3.
- Question 3: does it have dry, scaly skin? Yes.
Answer: A lizard is a reptile.
Flowering or non-flowering?
Sort: rose, fern, grass, moss, pine tree, apple tree.
- Does it make flowers? Rose, grass (small, plain flowers) and apple tree do.
- Fern and moss make spores, not flowers.
- A pine tree makes seeds in cones, not flowers.
Answer: Flowering: rose, grass, apple tree. Non-flowering: fern, moss, pine tree.
Practice check
Have a go, then check your answers. Each answer comes with an explanation.
Answer guide for parents
Animals with feathers belong to which group?
Birds — Only birds have feathers.
A dolphin breathes air and feeds its baby milk. Which group is it in?
Mammals — Feeding young milk is a mammal feature.
Which plant is non-flowering?
A fern — Ferns make spores, not flowers.
Which feature puts an animal in the mammal group?
It has fur or hair and feeds its young milk — Mammals have fur or hair and feed their babies milk.
A frog has smooth, damp skin and starts life in water. Which group is it in?
Amphibians — Frogs are amphibians.
How many legs does an insect have?
6 — All adult insects have six legs.
A pine tree makes its seeds inside ____.
cones — Pine trees are non-flowering and make seeds in cones.
Grass has tiny flowers. Is grass a flowering or non-flowering plant?
flowering — Grass makes small flowers, so it is a flowering plant.
Watch out for
- Students often think whales and dolphins are fish because they swim. They breathe air and feed their young milk, so they are mammals.
- Students may think bats are birds because they fly. Bats have fur and feed their babies milk, so they are mammals.
- Many students think grass and trees do not flower because the flowers are small or plain. Most trees and all grasses are flowering plants.
Tips for parents
- Play 'twenty questions' with animals, only allowing yes/no questions about features.
- On a walk, look closely at grass heads and tree blossoms to find small flowers.
- Safety: look but do not touch wild animals, insects and spiders, and wash hands after handling plants.
Go further
- Make your own yes/no key for six toy animals and test it on someone else.
- Collect pictures of 'odd one out' animals, such as a penguin (bird that cannot fly), and explain their group.
- Look under a fern leaf for the brown spots where spores are made.
About 45 minutes
You'll need
- Animal picture cards (cut from magazines or drawn): dog, whale, bat, eagle, penguin, snake, lizard, frog, shark, goldfish, beetle, butterfly
- Real or pictured plants: a flowering garden plant, grass, a fern, moss and a pine cone or pine branch
- Paper for a yes/no key
Key words
- classify
- To sort things into groups based on features they share.
- mammal
- An animal with fur or hair that feeds its babies milk.
- reptile
- An animal with dry, scaly skin, such as a lizard, snake, turtle or crocodile.
- amphibian
- An animal with smooth, damp skin that usually starts life in water, such as a frog.
- insect
- A small animal with six legs and three body parts.
- flowering plant
- A plant that makes flowers, which then make seeds.
Still tricky?
For parents
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