Classification

Classification - organisation of living organisms into groups according to their shared similarities

Taxonomy - study of principles behind classification 

Why do we classify? If one organism useful, chances others in group are for; medicine, food, useful genes (e.g. disease resistant - crops), building materials 

How do we classify? Modern classification system = phylogenetic hierarchy 

Hierarchy - large group of organisms divided into smaller + smaller sub-groups = taxons 

Phylogenetic - organisms grouped to reflect evolutionary relationships 

• Kingdom
• Phylum
• Class
• Order 
• Genus 
• Species 

All organisms placed in one of five Kingdoms 

• Animalia
• Fungi
• Plantae
• Protoctista 
• Prokaryotae 

Species - a group of organisms that can interbreed to produce fertile offspring 

All species known by latin name - avoids confusion of local names and different languages

Made up of two words - binominal 

Italicised if typed, underlined if hand written 

To classify - look for similarities and differences between organisms 

Similar morphology - structure of organism (outward appearance and internal structure) e.g. homologous structures

Similar biochemical make-up - techniques developed - examine relatedness of organisms - compare sequence of bases in DNA/amino acids in proteins  

Fossil record 

Homologus structures - body parts of different…