Classification

While there is a lot of variation between organisms, they also have a lot of features in common.

On the next slide is an activity comparing a cow and a dolphin. It may sound like they do not have many things in common but you may be surprised.

The activity looks at six different features – take a guess now at how many you think they have in common.

Common features

Classification

Common features

As you saw a dolphin and a cow do have things in common. Scientists use these common features to put organisms into groups. It would be a bit like you grouping your class in terms of their eye colour.

This kind of grouping is called CLASSIFICATION.

Before we look at the classification system that scientists invented lets see how you would classify some organisms.

Classification

Look at the organisms on the next page. Notice the similarities that they have to each other. From these similarities see if you can group them into four different groups.

How you group them is completely up to you. However, you must be able to tell other people why you grouped each of the organisms together.

Good Luck!

Classification

How did you group your organisms?

One way that a scientist might have grouped them is to putthem into the following four groups:

You may have heard some of these words before. They come from a scientific way of classifying organisms.

Move on to learn more about this classification system.

1. Plants

2. Birds

3. Mammals

4. Reptiles

Scientists across the world all use and recognise the same classification system.

In this classification system they start off using very big groups that include a lot of animals, and then move down to smaller groups that do not include as many animals.

The biggest groups are called the KINGDOMS. All living things are classified into five different kingdoms.

The Classification System

Kingdoms

Kingdoms

1. Invertebrates

These animals do not have a backbone. They have soft inner bodies which are held in shape by a flexible covering of outer cells or by a hard covering called an exoskeleton.

2. Vertebrates

These animals have a backbone. They have a firmer body because of the muscles that connect to their skeleton.

Animal ClassificationAnimals are first split up into two different groups:

Animal Classification

Animal Classification

Vertebrate features

Kingdoms

Classifying

whaletuna

perch

shark

sprat

sturgeon

trout

flounder

salmon

seahorse

The Odd One Out

Look at the names of the organisms below. In terms of classification which of these is the odd one out and why.

The whale is the odd one out. All of the rest are fish, a whale is a mammal.

ravenpenguin

platypus

duck

kiwi

swan

robin

eagle

pigeon

owl

Look at the names of the organisms below. In terms of classification which of these is the odd one out and why.

The platypus is the odd one out. All of the rest are birds, a platypus is a mammal.

The Odd One Out

Look at the names of the organisms below. In terms of classification which of these is the odd one out and why.

caterpillarladybird

ant

moth

horse fly

silverfish

scorpion

cockroach

lice

cicada

The Odd One Out

The scorpion is the odd one out. All of the rest are insects, a scorpion is an arachnid.

Invertebrates

• No backbone

• Normally have an exoskeleton

Jellyfish and sea anemones

• Jelly-like body.• Have tentacles with stinging cells

to catch food.

Flatworms

• Flattened body with no segments (divisions).

Roundworms

• Long thin body with no segments.

Segmented worms

• Long, tube-shaped body made of segments.

Molluscs

• Many have a shell.• Body not in segments.• Move around on a muscular foot.

Starfish and sea urchins• 5 ‘arms’ or star-shaped pattern on

their bodies.• Spiny skins

Arthropods

• Jointed legs.• Body has a hard outer skeleton• They can be divided into 4 smaller

groups: Crustaceans, Insects, Spiders, Centipedes and millipedes.

Arthrodops: Crustaceans

• Chalky outer skeleton.• Most live in water.

Arthropods: Insects

• 6 legs.• 3 parts to the body.• Have wings.

Arthropods: Spiders

• 8 legs.• 2 parts to the body.• No wings

Arthropods: Centipedes and millipedes

• Long body made up of segments.• Many legs.