Classifying Living Things: a full term of science

Ten ready-to-teach lessons for Year 7 Biological sciences. Print this pack and the term is prepared: every lesson comes with a step-by-step plan, the questions to ask, a student worksheet, cut-out cards or exit tickets, an assessment kit and worked answers.

Start here: five minutes to Monday

1. Skim the term at a glance on the next page.
2. Print the lesson you need. Each lesson is three A4 sheets: plan, worksheet, cards or tickets.
3. Gather the few items under “You need” on the plan. Most come from the classroom or the supermarket.
4. Open the free interactive unit on your board or projector. Every plan tells you which picture to show and when.
5. Teach straight from the plan. Timings, talk prompts, misconceptions and worked answers are all on the one page.

For any Year 7 science teacher

The pack suits a science specialist and a teacher working outside their own subject alike: each plan explains the idea in plain words, lists the misconceptions students bring, and gives worked answers. The big idea of the term: life on Earth is enormously diverse, and scientists bring order to it by grouping living things by the features they share, from broad kingdoms down to single species. Tools such as dichotomous keys use those features to identify an unknown living thing step by step, and a good key, like any classification, is revised when it meets something new.

Two ways to run each lesson

Every lesson works as one 60-minute block, or as two 30-minute sessions; the split point is marked in every plan. Look ahead: Lesson 7 needs a dry day and leaf litter from the school grounds, and Lesson 8 needs mushrooms bought the day before, with the spore prints left overnight.

Safety and care in one look

In the leaf-litter lessons, students wear gloves, move animals with a spoon or a soft brush, never handle spiders, centipedes or scorpions, and return the litter and its animals where they were found. Mushrooms come from the supermarket and are never eaten in class; no one picks or tastes a wild mushroom. Everyone washes their hands after litter, soil and fungi.

The term at a glance

One lesson a week for a term. Each lesson stands on the ones before it, so run them in order where you can.

How the sequence builds

Lessons 1 to 3 ask why we classify, which features make good rules, and how the levels from kingdom to species fit together. Lessons 4 and 5 use and then build dichotomous keys. Lessons 6 to 8 tour the big groups: vertebrates, invertebrates found in leaf litter, and plants, fungi and bacteria. Lesson 9 tests the key against animals it was not written for and shows how new evidence changes classification. Lesson 10 brings it together.

Curriculum links (Australian Curriculum V9)

The whole term teaches the Science Understanding descriptor AC9S7U01 quoted on the cover. The lessons also work these Science Inquiry and Human Endeavour descriptors:

Assessment in this pack

• Every plan ends with “Answers and look-fors”: what meeting the idea sounds like in a Year 7 voice, with working.
• The assessment sheet near the front has a class observation checklist and a three-level rubric.
• Lesson 10 is the summative pair: classifying and keying six sea animals, plus the “Show what we know” check.

Materials for the whole term

One gathering session covers all ten lessons. Most lessons need only the cards in this pack; Lessons 7 and 8 need a few things from the school grounds and the supermarket. Collect the leaf litter on the morning of Lesson 7, and buy the mushrooms the day before Lesson 8.

The one-trip list

• From the classroom: scissors, glue sticks, A3 paper, sticky notes, a timer, magnifiers, white trays or sheets of paper, plastic spoons, soft paintbrushes, plastic cups.
• From the supermarket: flat or field mushrooms with open gills, and dark paper or card for the spore prints.
• From the school grounds, with permission: leaf litter from under a tree, moss, a fern frond, a pine twig or cone and a flowering plant.
• To borrow: garden or disposable gloves for every student in Lesson 7.

Safety and care in one look

• Leaf litter: gloves on, animals moved with a spoon or brush, no touching spiders, centipedes or scorpions, and everything returned to the same tree.
• Mushrooms come from the supermarket and are never eaten in class; no one picks or tastes a wild mushroom.
• Everyone washes their hands after litter, soil, moss and mushrooms.

Assessment without extra work

The term assesses itself. Every lesson plan ends with worked answers and look-fors, and Lesson 10 is the summative pair: the sea-animal task, with its key tested by a partner, and the final check. This sheet is the place to note what you see along the way.

The three levels

Class observation checklist

A tick a lesson is plenty; the Lesson 10 task and check fill the gaps.

Word wall cards

Cut out the cards and build the wall as the words arrive: classification, characteristic and kingdom in Lesson 1; vertebrate and invertebrate in Lesson 2; species, genus and scientific name in Lesson 3; dichotomous key and couplet in Lesson 4; mammal in Lesson 6; arthropod in Lesson 7; fungus, spore and bacteria in Lesson 8.

Dear families

This term in science, Year 7 learns how scientists bring order to the enormous variety of life on Earth. Students sort living things by the features they share, learn the levels from kingdom to species and the two-part scientific names, and use and build dichotomous keys, which identify a living thing through a series of two-way choices.

Along the way your student will argue whether a dolphin is a fish, race to build classification ladders for Australian animals, survey the tiny animals in the leaf litter at school, make a mushroom spore print, and find out what happens when a key meets an animal it was not written for.

Try this at home

• Sort the pantry or a drawer by one rule, then by a different rule. Which rule would anyone else follow the same way?
• On a walk, count the legs of a few small animals you see, without touching them. Insect, spider or something else?
• Look up the scientific name of a favourite animal. Which part is the genus?
• Find a living thing in the garden that would be hard to sort. What makes it tricky?

What to ask your scientist

• Why is a dolphin not a fish?
• What is a dichotomous key, and what goes wrong when it meets something new?
• Why is a mushroom not a plant?
• What did your class find in the leaf litter?

A small note on care: in the leaf-litter lesson students wear gloves and leave spiders and centipedes alone, and in class no mushroom is ever eaten.

Warm regards,

The Year 7 science team

Printed from the free seegongsik Classifying Living Things teaching pack · seegongsik.com/au/y7/biological/AC9S7U01/pack

Why sort living things?

About two million kinds of living thing have been named, and many more have not. To study, name and talk about them, scientists sort them into groups by rules everyone agrees on. This lesson starts with the students’ own rules: groups sort eighteen organisms any way they like, compare their rules with the rest of the class, and then meet the rules scientists use. The point to land is that a good rule gives the same groups whoever applies it, and that body features make better rules than where a living thing lives or what people think of it.

We are learning to

• sort living things into groups by a rule, and say exactly what the rule is,
• explain why scientists need rules that everyone agrees on,
• describe three broad groups scientists use: animals, plants and fungi.

Success criteria

• I can sort the cards by a rule that another group could follow and get the same groups.
• I can explain why grouping by body features works better than grouping by where a living thing lives.

You need

• the organism cards (third sheet), cut out, one set per group of three,
• the worksheet (next sheet), one per student, and a pad of sticky notes.

Lesson flow (about 60 minutes)

Running two half-sessions instead? Sort and compare the rules in Session A. Show the board, re-sort and answer Part C in Session B.

Watch for these ideas

• “Grouping by where it lives is as good as any rule.” Habitat puts unrelated living things together: a crocodile, a cod and an octopus all live in water.
• “A mushroom is a plant.” It has no green parts and cannot make its own food, so scientists put fungi in a kingdom of their own.
• “There is one right way to sort.” Many rules work; scientists agree on body features so that everyone gets the same groups.

Make it easier, make it bigger

• Easier: start with one yes-or-no rule that makes two piles, then split each pile again.
• Bigger: find the card that is hardest to place and argue where it goes. The platypus has fur and feeds its young milk, but lays eggs.

Answers and look-fors

• Part A: any rule that is clear and used the same way every time. Look for students who state the rule (“has eight legs”) rather than list the members.
• Part B: animals A, C, E, G, H, J, L, N, O, P, Q, R (12); plants B, F, I, M (4); fungi D, K (2). The fungi clue: no green parts, so they cannot make their own food from sunlight; they feed on soil, wood or bread.
• Part C: 1. so everyone puts a living thing in the same group, names mean the same thing everywhere, and a newly found organism can be placed. 2. No: living in water is a habit, not a body feature, and it groups a reptile, a fish and a mollusc that are not closely related. 3. Often the platypus (an egg-laying mammal), the tree fern (a plant with no flowers or seeds) or the bread mould (not a plant at all).

Why sort living things?

A. Our own sort

B. The scientists’ groups

C. Why agree on rules?

Organism cards

Cut out the cards. Sort them into groups by a rule your group chooses, and be ready to say what the rule is.

Teacher note: keep the cards. Lesson 2 reuses the koala, the platypus and the frog, and Lesson 8 returns to the moss, the fern and the fungi.

Features that count

Lesson 1 showed that the rule decides the groups. This lesson asks which features make good rules. A good classification feature can be observed, does not change from day to day, and is shared by a whole group: a backbone, feathers, six legs. Habits, sizes and opinions make poor rules, and some features, such as laying eggs, are true for most of a group but have well-known exceptions. Groups sort twelve features, then use the best ones to settle an old argument: should a dolphin and a shark be in the same group?

We are learning to

• judge whether a feature is a good rule for classifying living things,
• compare two organisms by the features they share and the features that differ,
• argue from body features, not from looks or habitat, which group an animal belongs to.

Success criteria

• I can give a reason why a feature is, or is not, a good rule for classifying.
• I can explain, with two features, why a dolphin is a mammal and a shark is a fish.

You need

• the feature cards (third sheet), cut out, one set per group of three, and the organism cards from Lesson 1,
• the worksheet (next sheet), one per student.

Lesson flow (about 60 minutes)

Running two half-sessions instead? Sort the features and show the board in Session A. Do the dolphin and the shark, and the argument, in Session B.

Watch for these ideas

• “It lives in the sea, so it is a fish.” Whales and dolphins live in the sea but breathe air with lungs and feed their young milk: they are mammals.
• “If it has an exception, the feature is useless.” Laying eggs still helps for most reptiles and birds; scientists use it with care alongside other features.
• “The more features two animals share, the closer they are, whatever the features.” Shared habits and shapes, such as fins for swimming, can appear in unrelated groups.

Make it easier, make it bigger

• Easier: sort the feature cards into useful and not useful first, then pull out the ones that “mostly work”.
• Bigger: an echidna and a hedgehog both have spines. Find out which feature puts them in different groups of mammals.

Answers and look-fors

• Part A, useful: C Easy to check and shared by every vertebrate. E Every bird has feathers, and nothing else does. I Every adult insect has six legs. J Every mammal has fur or hair at some stage, and no other group does.
• Part A, not useful: B A dolphin, a fish and a crab all live in water and are not closely related. D An opinion about people, not a feature of the body. G Size changes as an animal grows and says nothing about its group. L A habit shared by spiders, frogs, birds and echidnas, which are not closely related.
• Part A, useful with care: A Most reptiles and birds do, but blue-tongue lizards give birth to live young and the platypus is a mammal that lays eggs. F Most birds fly, but emus and penguins cannot, and bats and insects fly too. H Fish do, but so do tadpoles and axolotls, which are amphibians. K Most mammals do, but so do blue-tongue lizards and some sharks, and the platypus does not.
• Part B: both: has a backbone; lives in the sea; streamlined body with fins. Dolphin only: breathes air with lungs; feeds its young milk; smooth skin with no scales. Shark only: breathes with gills; skin covered in tiny tooth-like scales.
• Part C: 1. breathing (lungs or gills), milk for the young, and the skin. 2. The dolphin is a mammal (lungs and milk) and the shark is a fish (gills and tooth-like scales). The shared features are a habitat and a shape for swimming, which many unrelated animals have. Bigger: the echidna lays eggs (a monotreme); the hedgehog gives birth to live young (a placental mammal).

Features that count

A. The feature sort

B. A dolphin and a shark

Write each feature in the right place in the circles.

C. Decide and argue

Feature cards

Cut out the cards. Lay down the three grey heading cards, then decide where each feature belongs. Test each one on the Lesson 1 organisms.

Teacher note: four cards go under each heading. Accept a different pile if the group gives a reason that holds up.

From kingdom to species

Scientists sort living things into groups inside groups. The broadest level is the kingdom; then come phylum, class, order, family and genus; the narrowest is the species, one kind of living thing. In the 1750s the Swedish naturalist Carl Linnaeus gave every species a two-part name: its genus, then its species word, such as Phascolarctos cinereus for the koala. In this lesson groups race to build four classification ladders, count how many levels two animals share, and see why the two-part name matters when common names mislead.

We are learning to

• order the levels of classification from kingdom to species,
• use shared levels to compare how closely two animals are related,
• write a scientific name correctly, and explain why scientists use it.

Success criteria

• I can build an animal’s ladder in the right order and say which level is broadest.
• I can write a scientific name with a capital for the genus and a small letter for the species.

You need

• the rank and name cards (third sheet), cut out, one set per group of three, and a timer,
• the worksheet (next sheet), one per student.

Lesson flow (about 60 minutes)

Running two half-sessions instead? Do the magpies, the nested boxes and the ladder race in Session A, and Parts B to D in Session B.

Watch for these ideas

• “A species is any group, such as birds.” Birds are a class; a species is one kind of living thing, such as the koala.
• “The species word is the name.” The name has two parts: cinereus, meaning ash-grey, is also the species word of some birds, so it never stands alone.
• “Animals that look alike are closely related.” The ladders decide that: a koala shares more levels with a wombat than with any bear.

Make it easier, make it bigger

• Easier: build only the koala and human ladders, then compare them level by level.
• Bigger: koalas and wombats share one more level than kangaroos do, between order and family. Find its name and what it suggests.

Answers and look-fors

• Part A: Kingdom Animalia, Phylum Chordata, Class Mammalia, Order Monotremata, Family Ornithorhynchidae, Genus Ornithorhynchus, Species anatinus.
• Part B: koala and common wombat 4 levels; koala and eastern grey kangaroo 4; koala and human 3 (kingdom, phylum and class: all four are mammals). Fewest: the human, so it is the least closely related of the three. More shared levels means more closely related. 3. 3: the platypus is a mammal, but in a different order (Monotremata, the egg-laying mammals).
• Part C: Koala, Phascolarctos cinereus; Common wombat, Vombatus ursinus; Eastern grey kangaroo, Macropus giganteus; Human, Homo sapiens. Corrected: Homo sapiens; Macropus giganteus; Vombatus ursinus.
• Part D: one common name, two birds. The Australian magpie is Gymnorhina tibicen and the European magpie is Pica pica, so the scientific names show at once that they are different species. Bigger: the suborder Vombatiformes, which suggests koalas and wombats are each other’s closest living relatives.

From kingdom to species

A. The platypus’s ladder

Word bank: Ornithorhynchidae, Animalia, anatinus, Mammalia, Ornithorhynchus, Chordata, Monotremata. Write each name next to its level, from the broadest to the narrowest.

B. Count the shared levels

C. Name it properly

D. Two magpies

Ladder race

Lay the seven grey rank cards in a column, from Kingdom at the top to Species at the bottom. Then build a ladder for each of the four animals: the koala, the common wombat, the eastern grey kangaroo and the human. Some names are used by more than one animal.

Teacher note: genus and species words are printed in italics, as scientists print them; handwritten names are underlined instead.

Using a dichotomous key

A dichotomous key identifies a living thing through a series of couplets: pairs of statements of which exactly one fits. Each choice leads to the next couplet or to a name, and the list of choices, such as 1b, 3a, 4b, is the path. Today pairs use a key to eight common leaf-litter animals to identify six animals from field notes, record each path, and check that another pair reaches the same name. If the weather and the grounds allow, add a tray of real leaf litter (the safe method is in Lesson 7).

We are learning to

• use a dichotomous key to identify an animal, recording the path we took,
• explain why each couplet must offer two clear, observable choices,
• check an identification by having someone else repeat it.

Success criteria

• I can record the path, such as 1b, 3a, 4b, that leads to each name.
• I can explain why two people using the same key on the same animal should reach the same name.

You need

• the field-note cards (third sheet), cut out, one set per pair, and the worksheet (next sheet), one per student,
• optional: a white tray of leaf litter per group, spoons, magnifiers and gloves.

Lesson flow (about 60 minutes)

Running two half-sessions instead? Demonstrate and identify the six in Session A. Swap, check and answer Part C in Session B.

Watch for these ideas

• Jumping straight to a name that looks right. The path is the evidence: read every couplet in order.
• Choosing a statement because it is partly true. Exactly one statement should fit; if neither does, the animal may not be in this key (Lesson 9).
• Counting the legs on one side only. Legs come in pairs, so count both sides.

Make it easier, make it bigger

• Easier: give the first two steps of each path, then let pairs finish it.
• Bigger: write a field note that keys out to the earthworm, and one for an animal that fits no name in this key.

Answers and look-fors

• Field note 1: 1b, 3b, 5b, 6b, 7b, millipede.
• Field note 2: 1b, 3a, 4a, beetle.
• Field note 3: 1a, 2a, garden snail.
• Field note 4: 1b, 3b, 5b, 6a, slater.
• Field note 5: 1b, 3b, 5a, spider.
• Field note 6: 1b, 3b, 5b, 6b, 7a, centipede.
• Part B: pairs should match. Where they do not, it is usually a misread leg count or skipping couplet 6.
• Part C: 1. so that everyone who looks sees the same thing and makes the same choice. 2. “Small” and “large” depend on what you compare with, so two people could choose differently; a count or a part you can see, such as six legs, cannot be argued with. Bigger: an earthworm note needs no legs and no shell; a cockroach fits nothing at couplet 4.

Using a dichotomous key

The key: eight leaf-litter animals

A. Identify the six

B. Swap and check

C. Good couplets

Field notes from the leaf litter

Each card is a note made by a student who found an animal but did not know its name. Use the key to name it.

Teacher note: with real leaf litter, students move animals with a spoon, never touch spiders or centipedes, and return everything to where it was found.

Build a key

Using a key is half the skill; building one is the other half. Groups take eight Australian vertebrates, pull out the features each card gives, and build a dichotomous key that separates all eight. Then another group tests the key on the cards, and any couplet that sends a card the wrong way gets rewritten. Along the way students meet a neat rule: a key for eight organisms always has seven couplets, because each couplet splits one group into two.

We are learning to

• choose features that split a group into two clear parts,
• build a dichotomous key as a branching diagram and as numbered couplets,
• test a key with someone else and improve it.

Success criteria

• My key leads every one of the eight animals to its own name.
• Every couplet in my key asks about one feature you can see on the card.

You need

• the animal cards (third sheet), cut out, one set per group of three, and a sheet of A3 paper per group,
• the worksheet (next sheet), one per student.

Lesson flow (about 60 minutes)

Running two half-sessions instead? Fill the table and build the key in Session A. Write the numbered key, test and fix it in Session B.

Watch for these ideas

• Questions about where an animal lives or what it eats. Use body features that the cards describe.
• Two features in one couplet (“Has fur and lays eggs?”). Each couplet asks about one feature.
• “Our key is wrong because it is different from theirs.” Many keys work; a key is right if every animal reaches its own name.

Make it easier, make it bigger

• Easier: give the first question, Has fur?, and the two animals that answer yes.
• Bigger: which feature on the cards splits the eight most evenly? Is a four-and-four split possible with these features?

Answers and look-fors

• Part A: Green tree frog NNNYNY; Koala YNNNNN; Laughing kookaburra NYYYNN; Murray cod NNNYYN; Eastern blue-tongue lizard NNNNNN; Platypus YNNYNN; Emu NYNYNN; Saltwater crocodile NNNYNN (letters in the column order fur, feathers, flies, lays eggs, gills as adult, moist skin).
• Parts B and C, one model key: 1. Has fur? yes go to 2; no go to 3 2. Lays eggs? yes Platypus; no Koala 3. Has feathers? yes go to 4; no go to 5 4. Can fly? yes Laughing kookaburra; no Emu 5. Breathes with gills as an adult? yes Murray cod; no go to 6 6. Moist skin with no scales? yes Green tree frog; no go to 7 7. Lays eggs? yes Saltwater crocodile; no Eastern blue-tongue lizard Any key is correct if all eight reach their own names using features from the cards.
• Part D: 7 couplets. Each couplet splits one group into two, so it takes 7 splits to turn one group of 8 into 8 groups of one.
• Bigger: fur, feathers, lays eggs each split the eight 2 and 6; none of the features on the cards splits them four and four, so some paths must be longer.

Build a key

A. Feature table (Y or N)

B. Our branching key

C. Our key as numbered couplets

D. Test and fix

Eight Australian vertebrates

Cut out the cards. Use only what each card tells you to build your key.

Teacher note: Lesson 6 brings these eight back with seven more vertebrates, some of which break the usual rules.

Five classes of vertebrates

Animals with a backbone, the vertebrates, fall into five classes: fish, amphibians, reptiles, birds and mammals. A few features tell them apart: the body covering, how the animal breathes, and how its young start life. Australia is full of animals that break one of the usual rules: a mammal that lays eggs, a lizard that gives birth, a fish with a lung. This lesson sorts fifteen vertebrates and asks students to explain each rule-breaker, so that they learn which features decide the class and which are only usual.

We are learning to

• sort vertebrates into the five classes by their deciding features,
• explain why an animal that breaks one usual rule still belongs to its class,
• argue from evidence where a puzzling animal belongs.

Success criteria

• I can place each of the fifteen animals in its class and name the feature that decided it.
• I can explain why the platypus is a mammal even though it lays eggs.

You need

• the vertebrate cards (third sheet), cut out, one set per group of three,
• the worksheet (next sheet), one per student.

Lesson flow (about 60 minutes)

Running two half-sessions instead? Sort the cards and test them on the board in Session A. Do the rule-breakers and the platypus case in Session B.

Watch for these ideas

• “Whales are fish because they live in the sea.” They breathe air with lungs and feed their calves milk: mammals.
• “A penguin cannot fly, so it is not a bird.” Feathers decide the class; flying is only usual.
• “Turtles and frogs are both amphibians because they live in water and on land.” A turtle has scaly skin and lays its eggs on land: a reptile.

Make it easier, make it bigger

• Easier: sort only the animals with no rule-breaking first, then add the rest one at a time.
• Bigger: find one more Australian rule-breaker, such as the echidna or a sea snake, and explain where it belongs.

Answers and look-fors

• Part A: fish A, F, K; amphibians B, D, O; reptiles C, H, M; birds E, G, L; mammals I, J, N.
• D Cane toad: Its skin is dry and warty, but it has no scales and its young grow in water with gills.
• F Grey nurse shark: It gives birth to live young, but its scales, fins and gills make it a fish.
• G Emu: It cannot fly, but feathers make it a bird.
• H Eastern blue-tongue lizard: It gives birth to live young, but dry scales and lungs make it a reptile.
• J Humpback whale: It lives in the sea, but lungs, milk and a few hairs make it a mammal.
• K Australian lungfish: It has a lung as well as gills, but its scales, fins and gills make it a fish.
• L Little penguin: It cannot fly, but feathers make it a bird.
• N Platypus: It lays eggs, but fur and milk make it a mammal.
• O Axolotl: It keeps its gills as an adult, but its skin and life in water make it an amphibian.
• Part C: the platypus has fur and feeds its young milk, the two features every mammal shares, so it is a mammal; laying eggs is usual for reptiles and birds but is not the deciding feature. Bigger: the echidna is also an egg-laying mammal; a sea snake is a reptile that breathes air and, like the blue-tongue, gives birth to live young.

Five classes of vertebrates

A. Our sort

B. The rule-breakers

Each of these animals breaks a rule that is usual for its class. Say which rule, and why it still belongs.

C. The platypus case

Fifteen vertebrates

Cut out the cards. Lay down the five grey heading cards, then place each animal in its class.

Teacher note: three animals belong to each class. 9 of the 15 break a rule that is usual for their class.

A leaf-litter survey

More than nine in every ten kinds of animal are invertebrates, and most of those are arthropods: animals with jointed legs and a hard outer skeleton, such as insects, spiders, slaters, centipedes and millipedes. The leaf litter under a school tree is full of them. Groups search a tray of litter, key out each animal with the Lesson 4 key, and tally them. The class pools its counts and turns them into percentages and a bar chart, then sorts arthropods into insects, arachnids and crustaceans. If the day is wet, the worksheet has an example class count to work from.

We are learning to

• survey the invertebrates in a habitat safely, and identify them with a key,
• organise class data in a table and a bar chart, and work out percentages,
• sort arthropods into insects, arachnids and crustaceans by their features.

Success criteria

• I can work out what percentage of the animals counted were arthropods, and show my working.
• I can explain why a spider and a slater are arthropods but not insects.

You need

• for each group: a white tray or sheet of paper, two plastic spoons, a soft paintbrush, a magnifier and gloves; a bucket of leaf litter from under a tree, collected that morning,
• the Lesson 4 key, the worksheet (next sheet), one per student, and the arthropod cards (third sheet), one set per group.

Safety: gloves on; move animals with a spoon or brush, never fingers; do not touch spiders, centipedes or scorpions; return the litter and its animals to the same tree; everyone washes their hands.

Lesson flow (about 60 minutes)

Running two half-sessions instead? Search, tally and return the litter in Session A. Do the class data and the card sort in Session B.

Watch for these ideas

• “Spiders are insects.” Spiders have eight legs and two body parts: they are arachnids.
• “Slaters are insects.” Slaters are crustaceans, related to crabs and prawns, and breathe through gill-like organs.
• “Every small crawling thing is a bug.” Worms and snails have no legs at all: one is an annelid worm, the other a mollusc.

Make it easier, make it bigger

• Easier: tally only three groups: insects, other animals with legs, and animals without legs.
• Bigger: compare litter from a sunny spot and a shaded spot, with the same amount of litter from each. Which differences could be due to chance?

Answers and look-fors

• Part A: counts vary; look for every animal keyed out before it is tallied, and for “Other” used honestly.
• Part B, example count: total 41 + 26 + 12 + 9 + 8 + 7 + 4 + 3 = 110. Insects (ants and beetles) 53 of 110 = 48%. Arthropods (every animal with jointed legs) 100 of 110 = 91%.
• Part C: 1. ants, 41 of 110. 2. 100 ÷ 110 × 100 ≈ 91%. 3. Any of: fast animals escape before they are counted; tiny animals such as mites are missed; one tray from one tree in one season; the time limit.
• Cards: insects B, F, G, L; arachnids A, D, I, K; crustaceans C, E, H, J. Centipedes and millipedes are arthropods too, in a fourth group, the myriapods.

A leaf-litter survey

A. Our group’s tally

B. The class data

Use the pooled class count, or this example count from another class.

C. What the numbers show

Which kind of arthropod?

Cut out the cards. Lay down the three grey heading cards and sort each arthropod by its features.

Teacher note: four cards go under each heading. Centipedes and millipedes form a fourth group, the myriapods.

Plants, fungi and bacteria

Animals are only one kingdom. Plants make their own food from sunlight. Fungi have no green parts and feed on other living or dead things, and many spread by spores. Bacteria are single tiny cells with no nucleus, and they live almost everywhere. Plants divide again by how they make new plants: mosses and ferns by spores, conifers and flowering plants by seeds. Groups start a mushroom spore print to read tomorrow, examine four kinds of plant, and sort twelve living things, including two that are easy to misplace.

We are learning to

• tell plants, fungi and bacteria apart by their features,
• sort plants into groups by whether they make spores or seeds,
• use evidence to explain why a mushroom is not a plant.

Success criteria

• I can place a living thing in the right kingdom and name the feature that decided it.
• I can give two pieces of evidence that fungi are not plants.

You need

• for each group: a supermarket mushroom with open gills (flat or field mushrooms), a sheet of paper half white and half dark, and a cup to cover it,
• for the class: a clump of moss, a fern frond with brown dots underneath, a pine twig or cone and a flowering plant, plus magnifiers,
• the living-things cards (third sheet), one set per group, and the worksheet (next sheet), one per student.

Safety: supermarket mushrooms only, and nothing is eaten. No one picks or tastes a wild mushroom. Everyone washes their hands after the mushrooms and the moss.

Lesson flow (about 60 minutes)

Running two half-sessions instead? Set up the spore prints and look at the plants in Session A. Sort the cards, answer Part C and read the prints in Session B, the next day.

Watch for these ideas

• “Fungi are plants.” Fungi have no green parts, cannot make their own food, and their cell walls are made of a different material from plants’.
• “Anything green is a plant.” Cyanobacteria are green and make food from sunlight, but each is a single cell with no nucleus: bacteria.
• “Bacteria are all germs.” Most are harmless or helpful: they make yoghurt, help wattles get nitrogen, and live in our gut.

Make it easier, make it bigger

• Easier: sort only the plant and fungus cards first, then add the bacteria.
• Bigger: yeast is a single cell, like a bacterium. Which feature on its card shows it is a fungus?

Answers and look-fors

• Part A: mosses, no tubes to carry water, so they stay small and grow in damp places; spores. ferns, tubes carry water up the stem, but no flowers; spores. conifers, tubes for water; seeds form in cones; seeds. flowering plants, tubes for water; seeds form inside fruits after flowers; seeds.
• Part B: plants B, F, G, L; fungi A, D, I, K; bacteria C, E, H, J.
• Part C: 1. any two: no green parts, so it cannot make food from sunlight; it feeds on the soil or wood it grows in; it spreads by spores from its gills, not seeds. 2. Each is a single cell with no nucleus, so it is a bacterium, even though it is green. 3. A pattern of thin lines radiating from the centre, matching the gills; supermarket mushrooms leave dark brown spores, which show on the white paper. Bigger: each yeast cell has a nucleus, which bacteria never have.

Plants, fungi and bacteria

A. Four kinds of plant

B. The kingdom sort

C. Explain it

Plant, fungus or bacterium?

Cut out the cards. Lay down the three grey heading cards and sort each living thing by the features on its card.

Teacher note: four cards go under each heading. Two are traps: the cyanobacteria are green, and the yeast is a single cell.

When the key meets something new

A key only works for the living things it was written for. Three animals that often turn up in leaf litter break the Lesson 4 key: the earwig is wrongly named a beetle, and the cockroach and the silverfish fit neither statement at couplet 4. Groups find where the key fails and rewrite it. Then the lesson widens: classification itself changes when new evidence arrives. In the 1990s, comparisons of DNA showed that fungi are more closely related to animals than to plants, and that the closest living relatives of whales are hippos.

We are learning to

• find where a key fails for an organism it was not written for,
• rewrite a key so that it separates the new organisms as well as the old,
• explain how new evidence can change a classification, and why that is a strength.

Success criteria

• I can show the couplet where each newcomer breaks the key.
• Our rewritten key leads all five six-legged animals to their own names.

You need

• the couplet strips (third sheet), cut out, one set per group, glue sticks and A3 paper,
• the worksheet (next sheet), one per student.

Lesson flow (about 60 minutes)

Running two half-sessions instead? Break the key and start the rewrite in Session A. Finish the rewrite and do Part C in Session B.

Watch for these ideas

• “If the key gives a name, the name must be right.” A key can mis-name an animal it was not written for, as it does the earwig.
• “Changing the key means the first key was wrong.” It was right for the eight animals it was written for; new animals need new couplets.
• “Scientists change groups whenever they like.” Changes follow new evidence, such as DNA, and other scientists check them first.

Make it easier, make it bigger

• Easier: fix the key for the earwig only, with one new couplet.
• Bigger: write a couplet that separates the slug from the board from the earthworm.

Answers and look-fors

• Part A, earwig: 1b, 3a, then couplet 4. Couplet 4a fits, so the key wrongly names it a beetle.
• Part A, cockroach: 1b, 3a, then couplet 4. Neither statement in couplet 4 fits: its wings overlap and it has no narrow waist.
• Part A, silverfish: 1b, 3a, then couplet 4. Neither statement in couplet 4 fits: it has no wing covers and no narrow waist.
• Part B, one model rewrite: 4a Hard wing covers that meet in a straight line and cover most of the body → Beetle; 4b No wing covers, short wing covers, or wings that overlap → go to 8. 8a A narrow waist between body parts → Ant; 8b No narrow waist → go to 9. 9a A pair of pincers at the tail end → Earwig; 9b No pincers at the tail end → go to 10. 10a Wings that overlap across the back → Cockroach; 10b No wings; three long bristles at the tail end → Silverfish. Any rewrite is correct if all five six-legged animals reach their own names with features from the notes.
• Part C: 1. No: they grouped fungi by the evidence they had, such as fungi growing in soil and not moving; DNA was new evidence that showed a closer link to animals. 2. A classification that can change when evidence arrives keeps getting more accurate. Bigger: earthworm, a long body made of ring-like segments; slug, a smooth body with no segments and feelers on its head.

When the key meets something new

The Lesson 4 key

A. Break the key

B. Our new couplets (to replace couplet 4)

C. Classification changes too

For a long time fungi were grouped with plants: they grow in soil and do not move. In the 1990s, scientists compared the DNA of many living things and found that fungi are more closely related to animals than to plants. DNA also showed that the closest living relatives of whales are hippos.

Couplet strips

Cut out the strips. Keep the couplets that still work, and write new strips to replace couplet 4.

Teacher note: number new couplets from 8 upwards, so they do not clash with couplets 5 to 7, which stay as they are.

Show what we know

The last lesson brings the term together. Students classify six sea animals, from a dugong to a sea star, and build a key that separates them; a partner tests the key. Then each student sits the final check on their own, and the class finishes with the unit quiz on the board.

We are learning to

• classify unfamiliar animals using the features that decide each group,
• build and test a dichotomous key without help,
• show what we know about classification on our own.

Success criteria

• My key leads all six sea animals to their own names, and a partner can use it.
• I can explain each answer on the final check with a feature or a reason.

You need

• the sea-animal task (next sheet) and the final check (third sheet), one each per student,
• the interactive unit open for the closing quiz.

Lesson flow (about 60 minutes)

Running two half-sessions instead? Do the sea-animal task and the key test in Session A, and the final check and the class quiz in Session B.

Watch for these ideas

• “The dugong lives in the sea, so it is a fish.” Ask: how does it breathe, and what does it feed its calf?
• A couplet that asks about two features at once, or about size or habitat. Ask: could two people answer it differently?
• “The sea star and the octopus are fish because they live in the sea.” Ask: does either have a backbone?

Make it easier, make it bigger

• Easier: give the first couplet of the key, Has a backbone?, and let students build from there.
• Bigger: add a seventh animal of your own choice to the key without changing its first couplet.

Answers and marking guide

• Task, Part A: dugong, mammal (vertebrate); weedy seadragon, fish (vertebrate); green sea turtle, reptile (vertebrate); blue swimmer crab, crustacean (invertebrate); blue-ringed octopus, mollusc (invertebrate); sea star, echinoderm (invertebrate).
• Task, Part B, one model key: 1. Has a backbone? yes go to 2; no go to 4. 2. Breathes with gills? yes Weedy seadragon; no go to 3. 3. Feeds its young milk? yes Dugong; no Green sea turtle. 4. Has jointed legs? yes Blue swimmer crab; no go to 5. 5. Has eight arms? yes Blue-ringed octopus; no Sea star. Any key works if all six reach their own names.
• Check: 1. has feathers. 2. One name that means the same species to every scientist in every language; common names change from place to place. 3. Phascolarctos cinereus.
• Check: 4. 1a, 2b, earthworm. 5. bird. 6. Any two: it breathes air with lungs; it feeds its calf milk; it has a few hairs.
• Check: 7. 9: each couplet splits one group into two, so 9 splits turn one group of 10 into 10 groups of one. 8. New evidence from DNA showed fungi are more closely related to animals than to plants; changing the classification to fit the evidence is how science improves.
• Scoring: 1 mark each for 1, 3 and 5; 2 marks each for 2, 4, 6, 7 and 8. The rubric near the front of the pack turns the task and the check into a level.

Six sea animals

A. Classify them

B. A key for the six

C. The hardest one

Show what we know

Show what you know about classifying living things. Read each item, then circle or write.

Teacher note: the marking guide is on this lesson’s plan; the rubric near the front of the pack turns the score into a level.