Why is an octopus's blood blue?

It carries oxygen using copper-based haemocyanin

It carries oxygen using iron-based haemoglobin

It takes its colour from the animal's diet

A coral reef is built by what?

Colonies of small animals related to jellyfish

What does a butterfly use its proboscis for?

Drinking nectar and other liquids

How is this quiz scored?

Every correct answer adds to your score, and there is no penalty for a wrong one. Your result is shown at the end with a full review of each question.

Do I need an account to play?

No. Every quiz is free and playable without signing in. An account is optional and only used to save your progress across devices.

Are explanations included?

Yes. Every question is followed by a short explanation of why the correct answer is right, so the quiz is useful whether you score well or not.

Animals & Wildlife Medium ⚡ 10 Questions ⏱️ ~7 Mins +100 XP

Insects and Invertebrates

Q: Can I retake this quiz?

Yes. You can replay any quiz as many times as you like, and the questions and answer options are reshuffled each time.

Vertebrates get the documentaries, but they are a rounding error in the count of animal species. This quiz belongs to everything else.

Start Quiz

Questions

~7m

Duration

Medium

Difficulty

+100

Max XP

About this topic

Invertebrate is not a real biological group so much as a leftover category: every animal that is not a fish, amphibian, reptile, bird or mammal. That leftover contains the overwhelming majority of animal species on earth, and most of the interesting body plans. A fair number of the questions here turn on classification, because the everyday names mislead. A woodlouse is not an insect. A coral is not a plant. A spider is not a bug in the strict sense. Getting those boundaries right is most of what it takes to understand the group.

Questions & answers

Insects and Invertebrates: all 10 questions and answers

Every question in this quiz is listed below with its correct answer and the reasoning behind it. Play first if you would rather not see the answers — or read through as a study sheet.

Play it instead

Show all answers and explanationsHide answers

1Which of these is not an insect?
- A Grasshopper
- B Spider Correct
- C Beetle
- D Ant
Answer: B. Spider

Why: Spiders are arachnids: eight legs, two body sections, no antennae and no wings. Insects have six legs, three body sections and a pair of antennae.
2Which group contains the most described animal species?
- A Beetles Correct
- B Butterflies and moths
- C Spiders
- D Bees, wasps and ants
Answer: A. Beetles

Why: Roughly one in four described animal species is a beetle, with something like 400,000 named so far. The geneticist J. B. S. Haldane is supposed to have said that a creator would show an inordinate fondness for them.
3Which insect hatches as a nymph rather than a larva, with no pupal stage?
- A Butterfly
- B Housefly
- C Mosquito
- D Grasshopper Correct
Answer: D. Grasshopper

Why: Grasshoppers hatch looking like small wingless adults and moult their way up to full size. Butterflies, flies and mosquitoes all pass through a pupa in which the body is substantially rebuilt.
4Spider silk is made of what?
- A Chitin
- B Keratin
- C Protein Correct
- D Cellulose
Answer: C. Protein

Why: Silk is a protein, spun as a liquid from glands in the abdomen and hardened as it is drawn out. A single orb-weaver makes several different silks, using a stiff one for the spokes and a stretchy, sticky one for the spiral that catches prey.
5Why is an octopus's blood blue?
- A It takes its colour from the animal's diet
- B It carries oxygen using copper-based haemocyanin Correct
- C It carries oxygen using iron-based haemoglobin
- D It carries no oxygen at all
Answer: B. It carries oxygen using copper-based haemocyanin

Why: Haemocyanin turns blue when it picks up oxygen, in the way that haemoglobin turns red. Copper-based blood works better than ours in cold water with little dissolved oxygen, which suits most octopus habitats.
6Which of these is a crustacean rather than an insect or myriapod?
- A Woodlouse Correct
- B Centipede
- C Millipede
- D Earwig
Answer: A. Woodlouse

Why: Woodlice are land-living crustaceans, closer to crabs and lobsters than to anything with six legs. They still breathe through gill-like structures, which is why they die in dry air and stay under damp wood.
7A coral reef is built by what?
- A Colonies of algae
- B Compacted shell and sand
- C Hardened sponges
- D Colonies of small animals related to jellyfish Correct
Answer: D. Colonies of small animals related to jellyfish

Why: Coral polyps are cnidarians, in the same phylum as anemones and jellyfish, and they build stony skeletons of calcium carbonate. Most reef-building species also house algae in their tissues, which supply a large share of their food.
8How many pairs of legs does a millipede have on most body segments?
- A Three
- B Four
- C Two Correct
- D One
Answer: C. Two

Why: Two pairs per segment for millipedes, one pair per segment for centipedes, which is the quickest way to tell them apart. Despite the name, common millipedes have well under a hundred pairs.
9Roughly what share of described animal species are invertebrates?
- A About 30 per cent
- B About 95 per cent Correct
- C About 70 per cent
- D About 50 per cent
Answer: B. About 95 per cent

Why: Animals with backbones make up only a few per cent of the described total. Insects alone outnumber all vertebrate species many times over.
10What does a butterfly use its proboscis for?
- A Drinking nectar and other liquids Correct
- B Chewing leaves
- C Detecting scent
- D Spinning silk
Answer: A. Drinking nectar and other liquids

Why: The proboscis is a coiled tube that works as a drinking straw and uncoils when the butterfly feeds. Butterflies taste with sensors on their feet, which is how a female checks a leaf before laying eggs on it.

Read alongside this quiz

How animals solve the problems we all have

Staying warm, finding the way home, sleeping safely. Every species faces the same short list, and the answers are inventive.

4 min read

Frequently Asked Questions

How is scoring calculated for this quiz?

Each correct answer awards 10 XP. There is zero point penalty for incorrect guesses, encouraging learning through exploration.

Can I retake this quiz?

Yes! You can retake any quiz as many times as you like, or use the Practice Mistakes mode at the end to review questions you missed.

Are explanations provided for every question?

Absolutely. As soon as you select an option, QuizKite displays a detailed explanation card explaining why the answer is correct.

QuizKite Quality Guarantee

Every quiz on QuizKite is researched, written and fact-checked by hand against reliable references, with an explanation for each answer. Read our full Editorial Policy to learn more about our content standards.

Keep going