Year 7 Science · Unit 1 · Lesson 3
Foundation Worksheet
Learning Goals
Fill the gap
Choose the correct word from the word bank. Each word is used once. Two words are not needed: cross them out.
An animal with a backbone is called a . Its backbone is a chain of small bones called , and it sits inside the body. An animal with no backbone is an . Many of these animals, such as ants and crabs, wear a hard skeleton on the outside of the body, called an . About of all animal species have no backbone. A dichotomous key is a list of questions, and every question has exactly possible answers.
1. Name the five classes of vertebrates and give one Australian example of each class.
Sort it
Ask “Does it have a backbone?” Then write each Australian animal in the correct box. The boxes do not hold the same number of items.
Vertebrate (has a backbone)
Invertebrate (no backbone)
True or false? Fix the false ones
Circle T or F. If a statement is false, correct it on the line.
1. All reptiles lay eggs.
Correct it:
2. Spiders are insects because they have six legs.
Correct it:
3. Fish breathe using gills.
Correct it:
4. A green tree frog can live anywhere on land, even in a dry desert, because its skin stops it losing water.
Correct it:
5. Birds are the only animals that grow feathers.
Correct it:
Use a dichotomous key
Scenario: a backyard bug hunt
A Year 7 class turns over logs and pot plants in the school garden and finds five invertebrates. They record what each one looks like in Table 1. Then they use Key 1 to identify each animal. Start at step 1 for every animal and follow the arrows until you reach a name.
| Animal | What the class saw | Name from Key 1 |
|---|---|---|
| A | 8 legs; 2 body parts; hard outer skeleton | |
| B | No legs; long, soft body; no shell | |
| C | 14 legs; grey armour; found under a damp log | |
| D | 6 legs; 3 body parts | |
| E | No legs; soft body inside a coiled shell |
Source: made-up observations for this worksheet.
| Step | Question | If yes | If no |
|---|---|---|---|
| 1 | Does it have legs? | go to step 2 | go to step 4 |
| 2 | Does it have more than 8 legs? | slater (crustacean) | go to step 3 |
| 3 | Does it have 8 legs? | garden spider (arachnid) | ant (insect) |
| 4 | Does it have a shell? | garden snail (mollusc) | earthworm (worm) |
2. Use Key 1 to name animals A to E. Write each name in the last column of Table 1.
3. Write the path animal C takes through Key 1, step by step. Then explain why Key 1 asks about “more than 8 legs” before it asks about 8 legs.
4. Sam wants to change step 4 to “Is it slimy and gross?” Explain why this is not a good question for a key.
5. Mia says: “A dolphin is a fish, because it swims and lives in the sea.” Use the features of the vertebrate classes to explain whether Mia is right.
Fill the gap
vertebrate; vertebrae; invertebrate; exoskeleton; 95%; two. Not used: 5%, four.
Question 1
Fish, amphibian, reptile, bird, mammal (1); examples such as Murray cod, green tree frog, eastern brown snake, kookaburra, red kangaroo (2 for five, 1 for three or four). [3 marks]
Sort it
Vertebrate (6): platypus, eastern brown snake, green tree frog, white shark, sulphur-crested cockatoo, blue-tongued lizard. Invertebrate (4): redback spider, blue-ringed octopus, earthworm, box jellyfish.
True or false
1. False: most reptiles lay eggs, but some give birth to live young. 2. False: spiders have 8 legs, so they are arachnids. 3. True. 4. False: a frog’s thin, moist skin dries out fast, so it must stay near water; reptiles have waterproof dry scales. 5. True.
Question 2
A garden spider; B earthworm; C slater; D ant; E garden snail. 1 mark each. [5 marks]
Question 3
Step 1: legs, yes; step 2: more than 8 legs, yes: slater (1). A slater has a hard outer skeleton and could be mistaken for an insect or spider (1); asking about more than 8 legs first removes it before the key counts 6 or 8, so the leg rule is used only where it works (1). [3 marks]
Question 4
“Slimy” and “gross” are opinions, so people could answer differently (1); a key question needs two answers anyone can check by looking (1). [2 marks]
Question 5
Marking guide: 1 clear position (Mia is wrong); 1 dolphin is a mammal; 1 each for two features (breathes air with lungs, not gills; warm-blooded; feeds its young milk); 1 habitat is not class: class depends on body features (an olive sea snake lives in the sea and is a reptile). [5 marks]
Model answer: Mia is wrong; a dolphin is a mammal. It breathes with lungs, not gills, is warm-blooded and feeds its young milk. Class depends on body features, not habitat: a sea snake lives in the sea and is a reptile.
Common error: calling a slater an insect or spider; check for more than 8 legs first.