3.1 Classification Flashcards
what does the classification system consist of
Hierarchy system
- Domain
- Kingdom
- Phylum
- Class
- Order
- Family
- Genus
- Species
what is biodiversity
- a measure of the variety of living organisms and their genetic differences
why do we classify things
- there needs to be an internationally recognised way of referring to any particular living organism
- so when biologists from different countries discuss a particular organism, they need to be sure that they are all referring to the same one
what are the three domains
- ARCHAEA, BACTERIA, EUKARYOTA
who created the binomial system and what are the rules when using it
- Carl Linnaeus
- consists of two latin names, the first one is is the genus and the second one is the species
- must be written in italics
- genus name starts with an uppercase letter and species is all lowercase
- after first use, they are abbreviated to initial of genus names then the species names e.g.
H. sapiens
what is the morphological species concept and what are its limitations
that organisms can be grouped based off similarity of their physical characteristics, into species genus etc.
L - the appearance of an organism can be affected by many different things, and their can be a large amount of variation with a group of similarly related organisms
L - in organisms that show sexual dimorphism there can be a great variation between males and females
what is the reproductive/ biological species concept, its definition and what are its limitations
- the model of a species is based off reproductive behaviour of the organism
- a group of organisms with similar characteristics that can reproduce to produce fertile offspring
- L - all organisms in a species cannot attempt to interbreed to produce fertile offspring because they don’t all live in the same area
- L - less helpful in classifying plants which frequently interbreed with different species to produce fertile offspring
why is it often difficult to assign organisms to one species / identify a new species
- finding the evidence, many organisms have never been observed mating, especially if a new species is found that is similar to an existing species, setting up a breeding programme is expensive, time-consuming
- plants of a different species often interbreed to produce fertile hybrids, and it;s difficult to decide when the hybrids should be regarded as a new species
- many organisms don’t reproduce sexually, so any reproductive concept can’t apply to protoctists and fungi
- fossil organisms can’t reproduce but must be classified
why do we use gel electrophoresis
- to identify patterns between DNA or RNA sequences that can be used in species identification and the development of evolutionary models
how is the process of gel electrophoresis carried out
- the chemicals being compared are placed in wells in a gel medium in a buffering solution with known DNA/ RNA fragments
- DNA (only) is cut into fragments by restriction endonucleases
- DNA fragments are added to gel containing dye that binds to the fragments in gel and is visible under UV light
- an electric current is passed through the apparatus and the DNA fragments move towards the positive anode (due to negative phosphate groups)
- fragments move at different rates according to size and charge, plate is then placed under UV light and patterns of different bands can be identified
what is bioinformatics
- the development of software and computing tools that can organise and analyse raw biological data t make sense of large quantities of data being generated
describe the steps in DNA analysis
- DNA sequencing, the base sequences of all or parts of a genome of an organism is worked out
- DNA profiling, looks at the non coding areas of DNA for patterns that are unique to individuals
- bioinformatics, used to organise the large amounts of data produced from the previous steps
why is it important for scientists to look at all pieces of evidence from different studies
- because it is possible that a piece of evidence can be interpreted differently, so they should look at a variety of sources that should agree
what is the role of the scientific community
- they validate new evidence
- when a piece of research produces useful conclusions it is submitted to a scientific journal
- articles are submitted for peer review that will be read by a number of experts to see if it is reliable, if so, it will be published
why are scientific conferences held
to discuss ideas, to promote the development of new techniques in research, provides opportunities to challenge the validity of results that are being presented
encourages discussion from scientists all over the world
