Classification and binomial naming Starter Classification What do

Classification and binomial naming

Starter Classification What do you remember about classification from GCSE?

Learning objective To understand how and why we classify organisms Success criteria Learners should be able to demonstrate and apply their knowledge and understanding of: (a) the biological classification of species To include the taxonomic hierarchy of kingdom, phylum, class, order, family, genus and species AND domain. (b) the binomial system of naming species and the advantage of such a system

Classification Why do we classify organisms? To identify species To predict characteristics To find evolutionary relationships (common ancestors)

Key Terms Taxonomy The study of the principles behind classification Classification The process of organising of living organisms into groups. Natural classification – grouping according to how closely organisms are related and reflects evolutionary relationships Phylogeny The study of evolutionary relationships between organisms

Evolution of classification systems Carl Linnaeus started it all off 250 years ago using visible features of organisms - limited C 17 th microscopes allowed us to look at cells, later electron microscopes allowed us to look inside cells Physiology How living organisms work Biochemistry Comparison of biological molecules eg. Cytochrome c (protein used in respiration: almost all species have it, but it is not identical in all, the more similar the amino acid sequence the more closely related the organisms) DNA Comparison of DNA sequences – probably most accurate

Classification systems (from GCSE) Organisms can only belong to one group in the taxonomic hierarchy. As you rise through the ranks of classification (taxa) the individuals grouped together show more and more diversity Levels of Classification K P Crisps Only Fry Good Spuds Kingdom Phylum Class Order Family Genus Species

What is a species? The hierarchy ends with species. A group that can contain only one organism. A species is a group of similar organisms able to reproduce and produce fertile offspring. Scientists constantly update the classification systems because of discoveries about new species and new evidence about known organisms.

The 5 kingdoms Proposed by Robert Whittaker (We’ll come back to this next lesson in more detail) PROKARYOTES Prokaryotes

Kingdom vs Domain (We’ll come back to this next lesson in more detail) In 1990 Carl Woese suggested 3 Domain classification system based on fundamental differences in RNA He divided the prokaryotes into Bacteria (Eubacteria) Archaea (Archaebacteria) This is now widely accepted

Binomial System Originally started by Carl Linneaus Means ‘two names’ First word indicates the genus (generic name) Second word indicates the species (specific name) Unique (Latin) name e. g. Homo sapiens Genus always starts with a capital letter Can be abbreviated to H. sapiens If printed the text should be in italics of handwritten the text is underlined

Binomial System: Why was it needed? http: //www. bbc. co. uk/learningzone/clips/the-binomialsystem-of-classification/12892. html Different common name around the country Different common name in different countries Translation of language or dialects may give different names Same common name may mean a different species in a different part of the world