History Of Clasification Flashcards
Why have scientists designed classification systems?
As a way to organise biodiversity
How are organisms classified?
According to similarities and shared characteristics
What are taxa?
The groups into which organisms are classified
What is taxonomy?
The formal scientific classification of organisms
How were simple classification systems designed?
They were mainly based in shared physical characteristics
How did classification systems become more complex?
As scientists learnt more about the structure of cells, microorganisms, evolution, genetics and molecular biology
Who was Carl Linnaeus?
A Swedish botanist
What did Carl Linnaeus do in 1758?
He classified organisms into two kingdoms
What two kingdoms did Carl Linnaeus classify organisms into?
Plantae (plants)
Animalia (animals)
What kind of system of classification did Linnaeus use?
A hierarchical system
How did Linnaeus’s system work?
There were seven taxa under each kingdom into which organisms were classified
What are the seven taxa in the classification system?
Kingdom Phylum/division Class Order Family Genus Species
What is the difference between phylum and division?
Phylum for animals
Division for plants
Same level of classification, just for different things
What kind of classification is used nowadays?
A five-kingdom system
Why do we now use a five-kingdom system instead of a two-kingdom system?
More scientific information about organisms has been obtained, so we need more categories
Who proposed the five-kingdom system?
Robert Whittaker
What six main things are used to classify organisms into the five kingdoms?
Body structure Cell structure Composition of cell wall Motility Mode of nutrition Method of reproduction
What sorts of things are observed when looking at body structure?
Unicellular? Multicellular? Colonies?
What sorts of things are observed when looking at cell structure?
Nucleus? Types of organelles (chloroplasts)?
What sorts of things are observed when looking at composition of cell wall?
Cellulose? Chitin? No cell wall?
What sorts of things are observed when looking at motility?
Mobile / immobile
What sorts of things are observed when looking at mode of nutrition?
Autotrophic? Heterotrophic?
What sorts of things are observed when looking at method of reproduction?
Binary fission? Asexual? Sexual?
What two broad groups can organisms be divided into according to their cell structure?
Prokaryotes
Eukaryotes
What are prokaryotes?
Organism with cells that do not have true nuclei
Their DNA is not enclosed by a nuclear membrane
No true organelles occur in the cytoplasm
Which kingdom of organisms are prokaryotes?
Monera
What are eukaryotes?
Organisms with cells that have true nuclei
Their DNA is enclosed by a nuclear membrane
True organelles occur in the cytoplasm
Which kingdoms of organism are eukaryotes?
Protista
Fungi
Plantae
Animalia
