Chapter 4: genes again Flashcards
what is a species?
organisms that reproduce sexually and produce fertile offpsirng,
What is a deme? why is it important in thw study of genetics?
a Deme is the local population that produce offspring, it is the reproductive population, it is important to study because they carry on genetic lines
what is microevolution?
small scale, such as the changing of allele frequency, for example, the red hair gene is slowly disapearing
what is macroevolution?
large scale speciation that occurs after thousands of generations
what is the hardy-weinburg law of equilibirum?
the law is a mathematical formula to show the relationship between allele frequencies.
what is a synonymous point mutation?
altered triplet of dna, but same amino acid s created
what is a nonsynonymous point mutation?
a match that brings along different amino aicd, this can have profound affects on expression
what is a frameshift mutation?
change in gene due to insertion or deletion of a nitro base, which causes other triplets to rearrange
what is a transposable element?
mobile pieces of dna that can copy themselves into new areas of chromosome
what is klinefelters syndrome?
when males receive an extra x chromosome. typically results in lower fertility
what is directional selection? provide example
favours one extreme form of a trait, for example, human brains are larger
what is stabilizing selection? provide example
stabilizing selection favours average version of trait, for example baby weight
what is disruptive selection?
people on both extreme ends produce more offspring than average.
what is genetic drift?
random change in allele frequency over time provided that there is no selective advantage to one allele, it is more likely to occur in small communities who are endogamous.
what is the founders effect?
a small group from a larger population seperate geographically- this can lead to a change in alelle frequencie due to a smaller gene pool
