Pieces of Classification


The Binomial system/ Morphological species concept

Every organism is given 2 latin names: first name is its genus, second name is species

There are rules in creating binomial names:

  • use italics
  • genus has upper-case letter and species is lowe-case (eg Homo sapien)
  • after first use, name is abreviated to first initla and species name (eg: H.sapien)

The Morphological species concept:

definition of species based on internal and external appearence. In species with sexual dimorphism (male and female look different) could be mistakne for different species

1 of 6

Bioinformatics, Evidence for evolution and new mod


The development of software and computing tools to organise and analyse raw biological data. Using bioinformatics we can make sense and use info generated in DNA sequancing and profiling

Bioinformatics was used to discover 'the caviar con' (analysed DNA of caviar from prestigous species, found only 25% was actually from expensive species, the rest was fake) and the horse meat in chicken and pork scandal

Evidence for evolution

Fossil DNA and human evolution: scientists can use DNA from fossils and analyse it using the polymerase chain reaction (amplifies minute traces of DNA) and DNA profiling. People thought Neanderthals where our ancestors, but comparison of DNA has shown we are not decendants of them , but interbreeding did occure (some people are 2% neanderthall)

New models: scientists use data from DNA analysis to construct diagrams that model evolution of species

2 of 6

Race Between Pathogens and Medicine

1- original population includes some mutations

2- antibiotic taken

3- bacteria with resistence mutation more liekly to survive

4- new population has higher proportion containing the advantagous resistant mutation

5- antibiotic taken

6- only bacteria with resistence mutation survive

7- new population almost comlelely resistant to antibiotics

There are fears that eventually bacterial disease becomes the biggest killer in UK. 

Antibiotics are too wideley used for inapropriate reasons and people do not complete course of antibiotics which makes it easier for resistance to develop. We can stop this by: reducing use of antibiotics, better education, reduce use of antibiotics in farm animals

3 of 6

Adaptive Radiation

Allopatric speciation often followed by adaptve radiation: takes place when one species evolvs rapidly to form a number of different species which all fill ecological niches. 

Main expamle of adaptive radiation: Darwins Finches

  • small flock of finches on galapogos island (had a variation of allels)
  • different niches on the island fit the characterists of individual finches 
  • over generations the successful characterists permanenlty fit niches, allowed birds to reproduce and develop seperate species. Selection pressure was so high birds developed different beaks to fit favoured food source (eg: long thin beak good for poking wood for insecst)
4 of 6

Gene and Allele frequency and measuring genetic bi

Mutations are changes in DNA structure. Can be simple (change of single base pair) or obliteration/ duplication of entire chromosome. Can have different effects on phenotype.

Mutation increase gene pool of population; increases number of different alleles. Allele frequency is the relative frequency of a particular population. If the mutation is advantagous to species, it will be carried on and increase frequency. If disadvantagous, natural selection will often resualt in the removal of allele from gene pool

Measuring genetic biodiversity: the amount of genetic diversity is an important  measure of biological health eg: small genetic biodiversity of cheetas mean their numbers are dwindling and mutations are prevelent in geentic makeup. Models of the molecular phylogenic relationships betwen orgamisms are useful for measuring genetic biodiversity.

5 of 6

Ecosystem Services

Ecosystem services: services provided by environment that are beneficial to people, there are 4 main types

Provisioning services: ecosystems provide us with food, clothing fibre, fuel, water, medecine

Regulating services: eceosystems regualte and maintain environment, include water purification, air quality, pollination, pest controll

Support services: biodiverse ecosystems give support to other ecosystems eg: soil formation and nutrient cycling 

Cultural services : ecosystems are used for human recreation ( economy can rely on poeple visiting environment- tourism)

6 of 6


No comments have yet been made

Similar Biology resources:

See all Biology resources »See all DNA, genetics and evolution resources »