All living organisms are classified into different groups.
This allows a kind of 'filing system' so that any new discoveries are easily incorporated into a group and relationships between groups of similar organisms can be studied.
It also makes international communication easier and more efficient. That is because all new discoveries will have recognised names which are the same in all countries, and they will all belong to a universally accepted groups.
All organisms fit into 1 of 5 'kingdoms'.
The 5 kingdoms are called:
- Monera (also known as 'Prokaryota')
Here is a table which shows the features of each of the 5 kingdoms:
|Organisation||Unicellular||Unicellular,Filamentous or multicellular||Multicellular|
|Reproduction||Mostly asexual||Asexual and/or sexual||Most have sexual and asexual|
|Examples||Bacteria /Cyanobacteria||Algae / Protozoa||Mould / Yeast / Mushrooms|
|Reproduction||Alternation of generations - sexual and asexual||Mostly sexual with haploid gametes|
|Examples||Ferns / Conifers / Angiosperms||Sponges / Flatworms / Fish|
The way the kingdom is broken down is as follows:
- A number of species make up a genus.
- A number of genera make up a family.
- A number of families make up an order.
- A number of orders make up a class.
- A number of classes make up a phylum.
- A number of phyla make up a kingdom.
Another fundamental unit of classification is the species. The species is the lowest level of classification within each Kingdom.
All members of a species are capable of interbreeding to produce fertile offspring. They have a particular set of characteristics.
A genus is a group of similar or closely related species.
Ranunculus = genus name for buttercups. The Ranuculus genus includes:
Ranunculus aquatalis = water crowfoot
Ranunculus repens = creeping buttercup
A genus could include just one species in some examples, but more often it includes several species.
Most examination boards only require you to have good knowledge on the Animalia Kingdom.
Here are some examples of classifications within the Animalia Kingdom:
Useful tip: Use the following sentence to prompt you for the first letter for each classification below Kingdom:
Please Cool Off, For Goodness Sake!
The next two Learn-its will look at some of the features of the Animalia Kingdom in more detail.