5.3 Classification of biodiversity Flashcards
What is classification?
The process of grouping living organisms that share similr features
Why do we classify organisms?
- Help identify species
- Name new species
- Understand evolutionary relationships
- Convenience - makes the study of living organisms more manageable
What are the 8 taxonomic groups?
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* Domain - Archaea, Eubacteria and Eukaryotae
* Kingdom - Plantae, animalia, fungi, protoctista, prokaryotae
* Phylum - All the groups of organisms that have the same body plan e.g. possession of a backbone
* Class - a group of organisms that all possess the same general traits e.g. the same number of legs
* Order - Subdivision of the class using additional information about the organisms
* Family - A group of closely related genera e.g. dog and cat families
* Genus (genera) - A group of closely related species
* Species - the basic unit of classification. All members of a species show some variation but are essentially the same
What system is used to agree and develop the names of species?
The binomial system
* Universal among biologists and has been agreed and developed at a series of congresses
* Congresse atteneded by delegates from around the world are helf at regular intervals
* There are separate congresses for animals and for plants and fungi
What is the Binomail nomenclature?
A system that uses the genus name and the species name to avoid confusion when naming organisms
* a good example of cooperation and collaboratio between scientists
What is the Binomail nomenclature?
A system that uses the genus name and the species name to avoid confusion when naming organisms
* a good example of cooperation and collaboratio between scientists
What is a genus?
A group of species that share certain characteristics
What is a species?
A group of organisms that can freely interbreed to produce fertile offspring
Why is a mule infertile?
A mule is the offspring of a male donkey and a female horse - they are infertile due to an uneven chromosome count
What does the word taxon (taxa) mean?
Taxon is greek and means a group of something
* Taxa is the plural
What is the trend going up the hierarchy of taxa?
- the taxa include larger and larger numbers of species, which share fewer and fewer features
What are the 2 main categories of organisms from taditional classification?
- Eukaryote and prokaryotes
- This clasificatio nis now regarded as inappropritate because the prokaryotes have been found to be very diverse
What are the 3 major categories of organisms now? What are the 3 domains called?
Domains: Eubacteria, Archae and Eukaryota
What are the 3 major categories of organisms now? What are the 3 domains called?
Domains: Eubacteria, Archae and Eukaryota
What are members of the domains usually referred to as?
Bacteria, archaens and eukaryotes
What are members of the domains usually referred to as?
Bacteria, archaens and eukaryotes
What are some features of the 3 main domains?
Where can archaens found?
In a broad range of habitats including:
* Ocean surface
* Deep ocean sediments
* Oil deposits far below the surface of the Earth
* Water with very high salt concentration
* Temperatures close to boiling
Why were fungi difficult to classify into plants or animals?
- they were originally classified as plants
- they have a similar root system (hyphae) and cell walls (chitin) instead of cellulose
- but they rely on other living organisms to feed because they lack chloroplasts
What is not classified in any of the 3 domains?
Viruses because they have too few of the characteristics of life to be regarded as living organisms
What are eukaryotes classified into?
Kingdoms
What does each kingdom divide into?
Phyla, which are divided into classes, then orders, families and genera
The hierarchy of taxa for clasifying eukaryotes is thus kingdom, phylum,
What does each kingdom divide into?
Phyla, which are divided into classes, then orders, families and genera
The hierarchy of taxa for clasifying eukaryotes is thus kingdom, phylum,
What are the 4 kingdoms of eukaryote?
Plants, animals, fungi and protoctista
Which one of the 4 kingdoms of eukaryotes is the most controversial?
Protoctists because they are very diverse and should be divided up int into more kingdoms
What can classification be? (2)
Natural or artificial
What is the classification of a grey wolf?
What is the classification of a date palm?
What is artificial classification?
- is based on only a few characteristics
- Does not reflect any evolutionary relationships
- Provides limited information
- is stable
What is natural classification?
- Uses many characteristics
- Reflects evolutionary relationships (all members of a taxon have a common ancestor)
- Provides a lot of useful information
- May change with advancing knowledge
- Identification is easier
- prediction of the characteristics of species within a group (because all of the members of a group in a natural classification have evolved from a common ancestral species)
In natural classification, the genus and accompanying higher taxa consist of?
consists of al lthe spceis that have evolved from one common ancestral species
* All members of a genus or higher taxon should have a common ancestor
What can we expect from the members of a natural group to have because of common ancestry?
We can expect the members of a natural group to share many characteristics
Why can natural classification be problematic?
It is not always clear which groups of species do share a common ancestor
How can convergent evolution and adaptive radiation make natural classification problematic?
Convergetn evolution can make distantly related organisms appear superficially similar and adaptive radiation can make closely related organisms appear different
* thus making identifying common ancestors for natural classification more difficult
What can happen withen new evidence shows that members of a group do not share a common ancester?
The group should be split up into two or more taxa
What can happen withen new evidence shows that species classified in different taca are found to be closely related?
Two or more taxa are united, or species are moved from one genus to another or between higher taxa
How has the classification of humans caused more controversy than any other species?
- Using standard taxonomic procedures, humans are assigned to the order Primates and the family Hominidae
- There has been much debate about which, if any, of the great apes to include in this family
- Originally all the great apes were paced in another family, the Pongidae, but research shows chimpanzees and gorillas as closer to humans than orang-utans in the Pongidae
What are the advantages of natural classification?
- Identification of species
- Prediction of characteristics of species within a group
- Studying closely related species (especially for endangered.extinct species)
- Tracing evolutionary relationships
- Help conservation of species
Prediction of characteristics because all of the members of a gropup in a natural classification have evolved from a common ancestral spcies, they inherit similar characteristics
What are the advantages of natural classification?
- Identification of species
- Prediction of characteristics of species within a group
- Studying closely related species (especially for endangered.extinct species)
- Tracing evolutionary relationships
- Help conservation of species
Prediction of characteristics because all of the members of a gropup in a natural classification have evolved from a common ancestral spcies, they inherit similar characteristics
What is the five-kingdom classification system?
Prokaryotae
Protoctista
Fungi
Plantae
Animalia
What are the 4 main phyla in plantae?
- Bryophyta - mosses, liverworts and hornworts
- Filicinophyta - ferns
- Coniferophyta - conifers
- Angiospermophyta - flowering plants
What are the external recognition features of the phyla in plantae kingdom?
What are the external recognition features of bryophytes, filicinophytes, coniferophytes and aniospermophytes.
(Structure, vascularisation, reproduction, other features, examples)
How can be animalia phyla be differentiated?
- Body symmetry
- Nymber of body openings
-> None (pores)
-> one
-> two or more - Body segmentation
- Chordata
-> Whether it had a central bundle of nerves running along the center of the body
What are the external recognition features of the phyla in animalia kingdom?
What are the recognition features of Porifera, cnidaria, platyhelminthes, mollusca, annelida, arthropoda?
(Symmetry, body cavity, segmentation, other features, examples)
What are the external recognition features of the phyla in animalia kingdom?
What are the 5 largest classes of chordate?
- Bony ray-finned fish
- Amphibians
- Reptiles
- Birds
- Mammals
What are the recognition features of fish, amphibians, reptile, bird, and mammal?
(Body covering, reproduction, breathing, temperature, other features)
What are the differences between archaea and bacteria?
Archaea “ancient bacteria”
* Found in extreme environments (e.g. thermal vents, anaerobic conditions, highly acidic conditions)
* e.g. methanogens in intestine of cattle -release CH4
Bacteria “true bacteria”
* Most bacteria
* e.g. cyanobacteria
What are the differences between archaea and bacteria?
Archaea “ancient bacteria”
* Found in extreme environments (e.g. thermal vents, anaerobic conditions, highly acidic conditions)
* e.g. methanogens in intestine of cattle -release CH4
Bacteria “true bacteria”
* Most bacteria
* e.g. cyanobacteria
The relationship between the 4 types of systems (3-domain, 6-kingdom, traditional 5-kingdom systems)
