relatedness of organisms Flashcards
(22 cards)
what is divergent evolution
where common ancestral structure has evolved to perform diff functions
homologus structure defenition
structures in different specises with similar anatomical position and development origin from common ancestor
analogous structures defenition
various structures in different specieces having some function but have evolevd seperatley (dont share common ancestors)
divergent evolution defenition
development of different structures over long periods of time, from the equivalent structures in related organisms
convergent evolution
development of similar features in unrelated organisms over long periods of time related to natural selction of similar features in a common environment
pentadactyl defentiion
having five toes / figures
what does discrete mean
only fits into one group
tentative defenition
can change due to new evidence eg DNA, amino acids
homologus structures is what type of evolution
divergent evolution
homologus structures + divergent evolution meaning
same structures but changed for different functions evolved from a common ancestor
amalogus with what type of evolution
convergent evolution
analogus + convergent evolution
evolved because of natural selection (environment)
no common ancestor
what phylum are mammals
chordata
what are the 4 things used as genetic evidence for relatedness
dna base sequences
dna hybridisation
amino acid sequence
immunology
what is dna base sequence comparing
more closely related specieses show more similiarity in their DNA base sequence than those more distantly related
what is dna hybridisation
dna from both is extracted, seperated and cut into fragments
use heat to seperate the two strands - higher temp needed to seperate the more complementary the base pairs, closer relation
amino acid sequence
similiarity in the amino acid sequence of the same protein in two species will reflect how closely related they are
immunology
soluble antigens from one and soluble antibodies from another form insoluble antigen antibody complex and form percipitatte
more percipitate the closer related they are
morphological defenition of specieses
if 2 organisms look very similar they are likely to be in the same species’s
reproductive defneition of specieses
if 2 organisms are in the same specieses if they can interbreed to make fertile offspring
what is toxonomy
identification and naming of organisms
what does binomial system advantaged
one species one name
based on latin so can be used all over the world
implies that 2 species sharing part of their name are closely related
