Classification Flashcards
What is biodiversity?
A measure of the variety of different organisms and their genetic differences
What is taxonomy?
The science of describing, classifying and naming living organisms
What is another word for physical appearance and who put organisms into groups based on this?
- morphology
* aristotle
What are analogous features?
Features that look similar or have the same function
What are homogolous structures?
Structures that genuinely show common ancestry
What are the main taxonomic groups from the largest to smallest?
Domain, kingdom, phylum, class, order, family, genus and species
What are the three domains?
Archaea, bacteria and eukaryota
What kingdom does the archeae domain contain?
The archaebacteria: ancient bacteria thought to be early relatives of the eukaryotes. Often found in extreme environments
What kingdom to do the bacteria domain contain?
The eubacteria: they are the normal bacteria we think of
What are the four eukaryotic kingdoms?
- protocista: very diverse group of microscopic organisms. Some are heterophs (have to ear orhwr orgamisms), some are autorophs (they make their own food by photosynthesis. Examples include amoeba and chlamydomonas
- fungi: all heterophs. They have chitin in their cell walls
- plantae: almost all autotrophs, include mosses, ferns and flowering plants
- animalia: all heterotrophs that move their whole bodies around during at least one stage of their life cycle. Include the invertebrates and vertebrates
Who developed the first Scientifically devised classification system?
Carolus Linnaues
Linnaeus developed the binomial system. What is it?
In the binomial system every organism is given two latin names. The first name is the genus name and the second is the species name
What are the rules to writing binomial names?
- use italics
- the genus name has an upper case letter and the species name has a lower case letter
- after the first use binomial names are abbreviated to the initial of the genus and then the species name e.g. H. sapiens
What is a genus?
A group of species that all share common characteristics
What was the definition of species originally developed by Linnaeus?
A morphological species concept based soley on the appearance of the organisms he observed
What are organisms that show sexual dimorphism and what could they be thought to be in a morphological species model?
- they show a great deal of difference between the male and female
- they could be thought to be different species in a morphological species model
What is the most widely used definition of a species?
A group of organisms with similar characteristics that interbreed to produce fertile offspring
What are the advantages and limitations of defining species as a group of organisms with similar characterisitics that can interbreed to produce fertile offspring?
- it overcomes issues such as sexual dimorphism
- however not all of the organisms in a species can interbreed to produce fertile offspring because they live in different areas
What are the two slightly more sophisticated definitions of species based upon reproductive capability?
- a group of organisms with similar characterisitics that are all potentially capable of breeding to produce fertile offspring
- a group of organisms in which genes can flow between individuals
What is molecular phylogeny?
The analysis of the genetic material of organisms to establish their evolutionary relationships
What is the ecological species model?
Based on the ecological niche occupied by an organism. This is not a robust way of identifying species as niches may vary and many species occupy more than one niche
What is the mate-recognition species model?
A concept based on unique fertilising systems including mating behaviour. However many species will mate or cross-polinate with other species and may even produce fertile offspring