6.4 Classification of Living Organisms

Traditionally living things have been classified into groups depending on their ___________ and ____________ in a system developed by Carl Linnaeus.

• structure

• characteristics

What did Linnaeus classify living things into?

kingdom → phylum → class → order → family → genus → species

What is the mneumonic for classification?

• Kids — kingdom

• Play — phylum

• Chess — class

• On — order

• Fancy — family

• Glass — genus

• Stairs — species

What system are organisms named by?

Binomial system — genus and species

• As evidence of ___________ ___________ became more developed due to improvements in ___________, and the understanding of _____________ __________ progressed, new models of ______________ were proposed.

• Due to evidence available from chemical analysis there is now a ‘_______ _________ system’ developed by Carl Woese.

• internal structures

• microscopes

• biochemical processes

• classification

• three domain

What are the three domains?

• Archaea

• Bacteria

• Eukaryota

What are archaea?

Primitive bacteria — includes extremophiles

What are extremophiles?

Organisms that live in extreme environments.

What does eukaryota include?

• Protists

• Fungi

• Plants

• Animals

What are evolutionary trees?

• A method used by scientists to show how they believe organisms are related.

• They use current classification data for living organisms and fossil data for extinct organisms.

• Table 2 gives the classification of four plant species.

Group	Species 1	Species 2	Species 3	Species 4
Kingdom	Plantae	Plantae	Plantae	Plantae
Phylum	Spermatophyta	Spermatophyta	Spermatophyta	Spermatophyta
Class	Monocotyledonae	Dicotyledonae	Monocotyledonae	Dicotyledonae
Order	Poales	Fabales	Poales	Scrophulariales
Family	Cyperaceae	Fabaceae	Poaceae	Scrophulariaceae
Genus	Eriophorum	Pisum	Poa	Antirrhinum
Species	angustifolium	sativum	annua	majus

• Species 1 and 3 are the most closely related.

What information in Table 2 gives evidence for this? [1 mark]

Same order