Classification

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  There are so many species of organisms we need to have some means of grouping them.
In about  1750  Carolus Linnaeus, a Swedish naturalist, devised a system of grouping organisms into  categories based on characteristics, such as shape or structure.

It is his system we use today

The major classification levels,
from largest group to smallest

Kingdom - Phylum -Class - Order - Family - Genus- Species

Each kingdom is divided into several Phyla, each phylum into several classes, each class into several orders and so on.

There are 5 major kingdoms:
Bacteria 
Single celled animals
Fungi
Plants 
Animals

Each Kingdom is divided into smaller groups called Phyla. Each phylum is dovided into still smaller groups called classes. Each class is divevied into smaller groups and so on until the group is

example:  the Lion :  Felix leo
The genus name is written first (always Capitalized).
The species name is written second (never capitalized).

Kingdom: 
Phylum
Class
Order
Family
Genus
Species
Animal
Chordata (vertebrates)
Mammal
Carnivore
Cat (felidae)
Felix
Felis leo

Classification of the animal kingdom
For Common Entrance we need only know the name of the main groups (phyla) and some of the classes

in the table which follows the main groups (Phyla) are on the left (in dark blue) and the classes on the right (in green)

Underneath the name of each group are the FEATURES that make it part of that group and some example animals
(You do not need to know the Latin names (shown in brackets) for the Common Entrance exam)

Animals with a backbone 
Download VERTEBRATES worksheet
Vertebrates
(Phylum Chordata)
Vertebrates have an internal skeleton to support their body

 

These are divided into 5 smaller groups (or classes) shown on the right

Fish
 Body covered in scales. Lay jelly covered eggs in water. Live in water. Breath through gills
eg Shark, Herring, Eel, Minnow

Amphibians 
Skin damp with no scales. Lay jelly covered eggs in water. Adults live on land, young live in water.eg Frog, Toad, Newt

Reptiles 
Body has hard scales. Lay soft-shelled eggs on land.
eg Lizard, Snake, Tortoise, Crocodile

Birds *Warm blooded  (see body temperature)
Body covered in feathers. Lay hard-shelled eggs on land. Warm blooded.
eg Thrush, Eagle, Swan

Mammals *Warm blooded
Young born alive. Mother will suckle her young from mammary glands.
Body has hair or fur. Warm-blooded.
eg Man, Dog, Whale, Wombat, Hamster

Animals without a backbone
(invertebrates)

Jellyfish 
Jelly-like body, central mouth surrounded by tentacles.
 

Flatworms 
Worms with flat bodies. Most of them are parasites.
eg Tapeworm, Liver fluke

 

True worms
(Phylum annelida)
Worms with round bodies made up of segments (rings)
eg Earthworm, Leach

 
Arthropods 
(Phylum arthropoda)
Arthropods have an exoskeleton (a hard external skeleton), many pairs of jointed legs and a segmented body.

The Arthropods are divided into 4 smaller groups (or classes) shown on the right

Insects 
3 pairs of legs. Body divided into 3 parts. Often 2 pairs of wings.
eg Fly, Ant, Earwig, Flea

Arachnids (spiders)
4 pairs of legs. Body has 2 parts. No wings.

 
eg Spider, Scorpion, Mite

Crustaceans 
Usually 5 pairs of legs. Hard outside skeleton (exoskeleton).
eg Crab, Woodlouse, Barnacle

Millipedes and Centipedes :
  many pairs of legs

 

Molluscs
(Phylum Mollusca)
Have a muscular foot and a soft body. often have one or two shells.
eg Shell-fish (Cockle, Mussel, Oyster), Octopus, Squid, Slug, Snail

Starfish 
(Phylum Echinodermata)
5 arms which sometimes form a hard, round body. eg Starfish, Sea urchins

 

Body Temperature
*
A warm blooded animal keeps its body at a constant temperature 
eg humans have a body temperature of 37 C
A cold blooded animal has a body whose temperature varies according to the conditions.
eg The temperature of a fish would be slightly above that of the surrounding water (more if it had just been swimming rapidly) 
Only birds and mammals are warm-blooded. all other animals are cold-blooded

Classification of the The Plant Kingdom

1.Flowering plants: produce SEEDS. Eg grass, apple, oak, rose
 All other plants are NON-FLOWERING and do NOT produce seeds. Eg algae, moss and fungi.

2. Algae Single celled plants. Reproduce asexually by binary fission. Live in wet places. Have no leaves or roots.

3. Moss Reproduces asexually by making spores. Live in damp, shady places.

4. Ferns and Horsetails: plants that have a tough fibrous stem and grow from a rhizome just under the surface of the soil . Reproduce by making spores

 

Fungi are not true plants as they do not possess green chlorophyll so cannot carry out photosynthesis.

They take their food from the material they are growing on/in.

Reproduces asexually by making spores.

Examples of different fungi: mushroom, yeast, mould.

Fungi (along with bacteria) are very important in the food chain for the recycling of nutrients in the soil.

Some fungi are harmful and can cause disease in crops (eg potato blight).

Some fungi are useful to man eg yeast which is used to ferment sugar and produce alcohol in the brewing industry.

 

 

Words to know from this section
VERTEBRATE      Has an internal skeleton

INVERTEBRATE   Has no internal skeleton

EXOSKELETON   An external skeleton, like a hard skin.

WARM-BLOODED   Animals whose body temperature is constant are called warm-blooded. eg Human: body temperature 37oC.

COLD-BLOODED   Animals whose body temperature alters with the temperature of the surroundings eg fish