7a Flashcards
Define the term ‘species’ in the biological sense;
a group of populations which evolve independently.
Define Specialisation
process which new species form through isolation and genetic divergence.
Define reproductive isolation
inability to successfully breed outside of the group, this ensures evolutionary independence.
Define pre-mating isolating mechanisms
mechanisms which prevent insemination of different species (geographic, behavioural, ecological, mechanical incompatibility, temporal)
Define post-mating isolating mechanisms.
mechanisms which prevent or minimise the hybrid offspring from spreading their genes. (hybrids infertility, gametic incompatibility, hybrid inviability)
Allopatric speciation
when there is a physical barrier that separates the population and the two populations, genes flow divergently.
Sympatric specialisation
when the populations live in the same era however use differing resources
Adaptive radiation
when an event occurs which give a species opportunity to invade a variety of new habitats (dinosaurs extinction allowed mammals to populate)
list the factors that are the common causes of extinction;
Environment, predation and resources, adaptations which have narrow ecological niches
List the eight major taxonomic ranks of the Linnaean system
Domain, kingdom, phylum, class, order, family, genus, species
define clade
a segment of the evolutionary tree
define phylogeny
Modern classification focuses on the evolution of history of an organism. Also known as systematics it utilises evolutionary trees.
List the three domains of living organisms and the types of organisms found in each
Archaea - single cells with no nucleus (extremophiles)
Prokara - no nucleus present and are single cellular (virus, bacteria)
Eukarya - membrane bound organelles with nucleus they are often multicellular (arthropods, mammals, plants)
