Variation and classification Flashcards
species
group of organisms that are capable of breeding to produce fertile offspring
every organism in a species has the same…
anatomy, physiology, morphology and behaviour
classification
the process of sorting living organisms into groups, organisms within a group share similar features
why do scientists classify organisms?
-to identify species
-to predict characteristics
-to find or show evolutionary links
what are the levels in the system used to classify organisms?
-kingdom
-phylum
-class
-order
-family
-genus
-species
what happens as you move down the hierarchy?
the organisms share more characteristics but there are fewer in each group
what is the smallest unit of classification and why?
species as each group only contains one type of organism
what are the two types of classification?
-artificial classification
-natural classification
describe artificial classification
-groups organisms together based on observable characteristics
why can artificial classification lead to difficulties?
variation within a species can causes difficulties as there may be observable characteristics e.g. dogs look very different but are all the same species
describe natural classification
-organisms are grouped based on a common ancestor
-species may look different but be closely related e.g. the closest living relatives of the elephant are the manatee
how does natural classification work?
-through DNA sequencing scientists can find links between organisms by looking at their evolutionary relationships
what is phylogeny?
the study of evolutionary links
how are phylogenetic links established?
by studying the similarities and differences in DNA between species, the more similar the DNA the more closely related the species
what do phylogenetic trees show?
the evolutionary links between species
speciation events
when a group within a species separates from other members of its species and develops its own unique characteristics- shown by a split in branches
