B2a - classification Flashcards
How are organisms classified(7)
Kingdom,phylum,class,order,family,genus,species
Whyisitdifficulttoplaceorganismsintodistinctgroups
thevarietyoflifeisacontinuousspectrumwhichmakesitdifficulttoplaceorganismsintodistinctgroups
Explaintheimportanceofclassificationofspecies
makesiteasiertoidentifyevolutionaryandecologicalrelationshipsbetweenanimalsandspecies
Describe the systemsofclassifyingorganisms(6)
Natural
-basedonevolutionarylinks
-organismswith commonancestrygroupedtogether
Artificial
- basedonvisiblefeatures
- makes agroupoforganismseasiertoidentif
WhathastheuseofDNAsequencinginformationledto?(2)
biologistsrealisedthatsomeorganismsaremorecloselyrelatedthanoriginallythought
leads to reclassification of some organisms toformmoreaccuratelinksbetweenorganisms
Whydosystemsofclassificationchangeovertime(2)
toformmoreaccuratelinksbetweenorganismsasbiologistslearnmoreaboutorganisms(e.g. theirgeneticsandthesequence oftheirDNAbases)
-throughwhichwerealisethatsomeorganismsaremorecloselyrelatedthanoriginallythought
Howcanevolutionaryrelationshipsbetweenorganismsbedisplayed
usingevolutionarytrees
Howcantheevolutionaryrelationshipsoforganismsinagroupbemodelled(3)
byanalysingmultiplecharacteristicsandlookingforsimilaritiesanddifferences
the more characteristics analysed, the more accurate the evolutionary tree model becomes
ICT has facilitated analysing multiple characteristics
Define the term species
agroupoforganismswhicharecapableofinterbreedingtoproducefertileoffspring
Describethebinomialsystemofnamingspecies(4)
eachspeciesisknownbya2 partname
- firstnameisthegenus
- 2ndnameidentifiesa singlespecies
itistheinternationalbasisofnamingspeciesandpreventsconfusion
Explainsomeoftheproblemsofclassifyingorganismsintospecies(8)
Hybrids
- when members of two species interbreed
- are infertile, so cannot be classed as a species
Organismsthatonlyreproduceasexually(e.g. bacteria)
- do not interbreed - does not fit the definition of a species
- biologists classifythemasdiffspecies,basedoncharacteristics
Evolutionisacontinuousprocess
-organismsareslowlychangingandcaneventuallybecomenewspecies
Describe closely related species(2)
Shares arelativelyrecentcommonancestor
may have different features if they live in different types of habitats
Howcansimilaritiesanddifferencesbetweenspeciesbeexplained(2)
Ecological relationships
-e.g. similarities between different organisms that live in the same habitat
Evolutionary relationships
-e.g. relations between animals that live in different habitats