Horrible Science: What Animal's in the Box?

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What are classification keys?

Image of a classification key. It begins: does it have a backbone? Yes. Does it have wings? Yes. Does it lay eggs? Yes. It shows an image of a bird. The Horrible Science logo is in the bottom right corner.

Scientists like to sort living things into groups so they can understand them better.

To do this, they use a classification key. This is like a quiz with yes or no questions about what the living thing looks like or how it behaves.

Each answer leads to another question, and step-by-step, they get closer to finding out exactly what the living thing is.

A scientist from Sweden called Carl Linnaeus created the classification system that today’s system is based on.

He gave every living thing a two-part Latin name.

For example:

  • humans are called Homo sapiens

  • a house cat is called Felis catus

Image of a classification key. It begins: does it have a backbone? Yes. Does it have wings? Yes. Does it lay eggs? Yes. It shows an image of a bird. The Horrible Science logo is in the bottom right corner.
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Watch: What Animal's in the Box?

Learn about classification keys through a rather terrifying TV game show.

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How do we classify animals?

Image of a classification key. It begins: does it have a backbone? No. Does it have 6 legs? Yes. Is it small? Yes. Does it have stripes? Yes. It shows two images of a bee and a wasp. The Horrible Science logo is in the bottom right corner.

Classifying a new animal is like being a detective. To do it scientists follow a process.

  1. They look at its features and behaviour.
  2. Then, they compare it with other animals.
  3. They use this information to answer the questions in a classification key.
  4. They give the animal a special name, so scientists everywhere know exactly what it is.

As part of this process, animals are divided into two groups: vertebrates (which have backbones) and invertebrates (which do not have backbones).

Then each of these groups is divided further. Vertebrates are divided into five smaller groups: amphibians, birds, fish, mammals and reptiles.

Invertebrates are divided into seven smaller groups: molluscs, arachnids, echinoderms, insects, crustaceans, annelids and cnidaria.

This sorting and grouping of animals continues until scientists can give it a scientific, two-part name such as Homo sapiens.

Image of a classification key. It begins: does it have a backbone? No. Does it have 6 legs? Yes. Is it small? Yes. Does it have stripes? Yes. It shows two images of a bee and a wasp. The Horrible Science logo is in the bottom right corner.
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Horrible Science fact

Invertebrates make up around 97 per cent of all the animal species on Earth. A type of fish called the Greenland shark has the longest recorded lifespan of any vertebrates - one is thought to be around 400 years old - you’d need a big birthday cake to fit that many candles on!

Find out more about classification.

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Quiz

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How to use Horrible Science in the classroom

If you're looking to bring energy, humour and curriculum-aligned content into your science lessons, Horrible Science might just be your new secret weapon.

How to use Horrible Science in the classroom
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