Biology Edexcel Topic 4 (Classification)

4.7

What is classification

The organisation of organisms into groups

What is taxonomy

The classification of organisms into taxa - kingdom, phylum, class, order, family, genus, species

Name the five kingdoms

Animals, plants, fungi, protists and prokaryotes

What happens to the number of organisms in each taxon as you move down the heirarchy

The number of organisms in each taxon group decreases

What is the problem with getting organisms based on similarities and differences in their anatomy and behaviour

Organisms that are not closely related may look alike and behave similarly if they live in the same environment (e.g. sharks and dolphins), and some closely related species may look very different if they live in different habitats

What advancements in science have led scientists to reconsider the five kingdoms classification system

Microscopes, biochemistry and DNA and RNA analysis

Describe the three donations system of classification

Organisms are initially divided into an extra three groups - archaea, bacteria and eukarya, then put into the five kingdoms classification

Which domain do eukaryotic organisms belong to

Eukarya

Which domains do prokaryotic organisms belong to

Archaea and bacteria

Describe the domain bacteria

Consists of true bacteria - e.g. E.coli

Describe the domain archaea

Consists of primitive microorganisms and contains extremophiles which are adapted to live in extreme conditions - e.g. hot springs