Vertebrate Invertebrate English ESL Worksheets For Distance, 44% OFF - Free Printable

Let's solve this Invertebrates worksheet step by step. The goal is to:

1. Match each animal to its correct phylum (from the given choices).
2. Circle the animal that does not belong in each class (insects, crustaceans, arachnids).

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🔹 Part 1: Choose the Phylum

We’ll go through each animal and pick the correct phylum based on biological classification.

#### 1. Brittle star
- Options: cnidarian, echinoderm
- ✔ Answer: echinoderm
→ Brittle stars are marine animals with radial symmetry and a water vascular system — typical of echinoderms.

#### 2. Flea
- Options: arthropod, mollusk
- ✔ Answer: arthropod
→ Fleas are insects (a subclass of arthropods), with jointed legs and an exoskeleton.

#### 3. Sea anemone
- Options: cnidarian, echinoderm
- ✔ Answer: cnidarian
→ Sea anemones have tentacles with stinging cells (cnidocytes) and radial symmetry — classic cnidarians.

#### 4. Sea sponge
- Options: echinoderm, porifera
- ✔ Answer: porifera
→ Sponges are simple animals with pores and canals — they belong to Porifera, the simplest animals.

#### 5. Scallop
- Options: mollusk, porifera
- ✔ Answer: mollusk
→ Scallops are bivalve mollusks with two shells and a muscular foot.

#### 6. Leech
- Options: worm, cnidarian
- ✔ Answer: worm
→ Leeches are segmented worms (annelids), so they belong to worms (specifically, annelids).

#### 7. Sea urchin
- Options: cnidarian, echinoderm
- ✔ Answer: echinoderm
→ Sea urchins have spiny skeletons and radial symmetry — echinoderms.

#### 8. Tapeworm
- Options: cnidarian, worm
- ✔ Answer: worm
→ Tapeworms are parasitic flatworms — part of the worm group (Platyhelminthes).

#### 9. Coral
- Options: cnidarian, mollusk
- ✔ Answer: cnidarian
→ Coral polyps are colonial cnidarians that secrete calcium carbonate skeletons.

#### 10. Sea sponge (again)
- Options: echinoderm, porifera
- ✔ Answer: porifera
→ Same as #4 — porifera.

#### 11. Tick
- Options: arthropod, mollusk
- ✔ Answer: arthropod
→ Ticks are arachnids (part of arthropods), with jointed legs and exoskeleton.

#### 12. Octopus
- Options: mollusk, porifera
- ✔ Answer: mollusk
→ Octopuses are cephalopods — a class of mollusks.

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✔ Summary – Correct Answers for Phyla:

| Animal | Correct Phylum |
|------------------|--------------------|
| Brittle star | echinoderm |
| Flea | arthropod |
| Sea anemone | cnidarian |
| Sea sponge | porifera |
| Scallop | mollusk |
| Leech | worm |
| Sea urchin | echinoderm |
| Tapeworm | worm |
| Coral | cnidarian |
| Sea sponge | porifera |
| Tick | arthropod |
| Octopus | mollusk |

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🔹 Part 2: Circle the Animal That Does NOT Belong

Now we identify which animal doesn’t fit in each group.

#### 🐝 Insects
Animals: bumblebee, earwig, scorpion, potato bug

- Insects have:
- 3 body parts (head, thorax, abdomen)
- 6 legs (3 pairs)
- Usually 2 antennae

Check each:
- Bumblebee → insect ✔
- Earwig → insect ✔
- Scorpion → arachnid (8 legs, no wings) ✘
- Potato bug → insect ✔

➡️ Scorpion does not belong.

✔ Circle: scorpion

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#### 🦀 Crustaceans
Animals: kissing bug, hermit crab, crab, shrimp

- Crustaceans:
- Have exoskeleton
- Usually 2 pairs of antennae
- 5 pairs of legs
- Live in water or moist environments

Check:
- Kissing bug → true bug (insect) ✘
- Hermit crab → crustacean ✔
- Crab → crustacean ✔
- Shrimp → crustacean ✔

➡️ Kissing bug is an insect, not a crustacean.

✔ Circle: kissing bug

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#### 🕷️ Arachnids
Animals: black widow, tick, cave spider, termite

- Arachnids:
- 8 legs
- 2 body segments (cephalothorax + abdomen)
- No wings or antennae

Check:
- Black widow → spider → arachnid ✔
- Tick → arachnid ✔
- Cave spider → arachnid ✔
- Termite → insect (6 legs, 3 body parts) ✘

➡️ Termite is an insect, not an arachnid.

✔ Circle: termite

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✔ Final Answers:

#### Part 1: Phylum Matching
| Animal | Phylum |
|------------------|----------------|
| Brittle star | echinoderm |
| Flea | arthropod |
| Sea anemone | cnidarian |
| Sea sponge | porifera |
| Scallop | mollusk |
| Leech | worm |
| Sea urchin | echinoderm |
| Tapeworm | worm |
| Coral | cnidarian |
| Sea sponge | porifera |
| Tick | arthropod |
| Octopus | mollusk |

#### Part 2: Odd One Out
- Insects: ⭕ scorpion
- Crustaceans: ⭕ kissing bug
- Arachnids: ⭕ termite

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📝 Explanation Recap:

- Phyla are broad categories of animals based on body structure.
- Insects = 6 legs, 3 body parts
- Crustaceans = 10 legs, 2 antennae, aquatic
- Arachnids = 8 legs, no antennae, 2 body parts

By matching physical traits to definitions, we can classify these invertebrates correctly.

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