B15 - genetics and evolution Flashcards
who discovered the structure of DNA
Watson and Crick
who was Gregor Mendel
monk who studied genetics in pea plants
what are Mendel’s laws
law of dominance, law of segregation (each organism has 2 alleles for each gene and passes one on to their offspring), law of independent assortment (chromosomes are inherited separately from one another)
what was Jean Baptiste Lamarck’s theory of evolution
The more an organism used a certain feature, the more it grew
what was Darwin’s theory of evolution by natural selection
all species have variation by random mutation.
some individuals have more advantageous alleles than others, so are more likely to survive and reproduce, giving the advantageous allele to their offspring.
why was Darwin’s theory believed eventually but not Lamarck’s
Darwin had evidence (finches, etc)
what is speciation
where a species is geographically separated, and evolve differently until they cannot breed to produce fertile offspring, so are not the same species
how are fossils formed
creature dies and is buried in sediment, soft parts of body decay, minerals replace bones over millions of years
what is extinction
when all the members of a species die out
what is a mass extinction
when most species on earth go extinct within a few million years - 5 have happened so far
who did taxonomy
Carl Linnaeus
order of taxonomical classification
kingdom, phylum, class, order, family, genus, species
naming rules for taxonomy
Genus species in italics or underlined
