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Def: Polymorphism
Genetic trait with distinct phenotypes
What is nonrandom mating a deviation from?
Random mating
What are reasons for non-random mating?
Phenotypic resemblemce
Genetic relatedness
What are the types of deviatons due to phenotypic resemblances?
Positive assortment - tendency for like individuals to mate (ie
: similiar heights)
Negative assortment - tendency for unlike individuals to mate (ie
: dissimiliar heights)
What genes does non-random mating due to phenotypic resemblence affect?
Only genes that encode these traits
What are the types of deviations due to genetic relatedness?
Inbreeding
: - preferential mating between related individuals
Outbreding/Outcrossing
: avoidance of mating with related individuals
What Are types of Assortment?
Phenotypic resemblences
Genetic relatedness
What are the effects of assortive mating?
1
: Positive assortment and inbreeding increase homozygosity
2
: Negative assortment and outbreeding increase heterozygosity
3:Genotype frequencies change, but Allele frequencies do not
What are the two causes of inbreeding?
Mate choice
:
Population subdivision:
Define inbred
An individual whose parents are related
Define autozygosity
Two alleles that are identical by descent
Define allozygosity
Two alleles that are not identical by descent
What is the inbreeding coefficient?
(F): the probability that an individuals alleles are autozygous
What are the 5 effects of inbreeding on an individual?
Increases homozygosity across genes
Expression of recessive alleles
(taboos and organisms that routinely inbreed)
Inbreeding 2 effects at a pop level
Increased homozygosity relative to HW equilibrium
Genotype frequencies change without changing allele frequencies
Define Mutation
random change in the genetic material
What are the 2 types of mutation?
Gene (point) mutation
: produce new alleles
Chromosomal mutation
: produce new chromosomal arrangments
What is mutations importance in evolution?
It is not significant on a generation-to-generation time scale
It is the source of all novel genetic variation
"Mu" and "v" are directly proportional to _________.
Forward and backward mutational frequencies.
What are the 3 types of mutational equilibrium?
Stable
:
Unstable:
Neutral:
Migration vs Gene Flow
Same freaking thing
Define Migration
The non-random movement of alleles into or out of a population
What are the effects of migration?
Bring new alleles to the population -> bring new variation to gene pool
3 types of populations considered by migration are ________ and thier frequencies are__________.
Native
: with frequencies PnQn
Source
: PmQm
Conglomerate
: m+(1-m) (m= migration rate)
What are the two effects of migration?
Conglomerate becomes native and a new migration event occurs
Conglomerate/Native frequencies asymptotically approach those of the migrant population -> Qm=Qn
What is the "island model" for migration?
Migration is 2 way
There are many populations
All populations can evolve
What are the 4 assumptions of the Island Model?
All populations are on discrete "islands"
All populations are equal in terms of size, migration rate, etc... (migration rate should remain constant)
...but p and q do not have to be the same in each pop at the start
The number of populations is very large (infinite)
Island distances are not a factor
Gene flow alters frequencies ____?____ populations.
Within
Gene flow ___?___ genetic differences __?__ populations and is known as the "__?__."
Reduces
Among
Great Homogenizer
Gene flow __?__ speciation which __?__.
Retards
Requires Genetic Divergence
What eliminates the homogenizing effect of gene flow?
Geographical isolation.
"Real" populations subject to genetic drift becuase _____.
real pop are:
finite and can be very small
Define: Genetic Drift
Random sampling error
of gametes resulting in fluctuations in allelic frequencies from one generation to the next.
__?__ is another name for genetic drift.
Sewell Wright effect
Random sampling error is a result of __?__.
Observed outcome
s that are
different
from e
xpected probabilities
due to
random chance
.
__?__ is a measure of random sampling error and gets __?__ as k gets __?__.
Variance
smaller
larger
(sigma)^2=pq/k
Genetic drift is __?__ so direction and magnitude cannot be __?__.
Random
Accurately Predicted
The long term effect of genetic drift is __?__
loss of one allele
while the
other becomes fixed
__?/?__ is a function of population site.
fixation/loss rate
genetic drift causes variation among populations to __?__
increase
The two special cases of genetic drift are __?__ and __?__.
Bottleneck effect
Founder effect
The Bottleneck Effect is __?__.
when populations undergo a drastic reduction in population size (N)
The bottleneck effect results in __?__ and __?__.
change in allele frequency
loss of genetic variation
How is variation lost from bottleneck restored?
Genetic flow/Migration or Mutation (very slow)
The Founder Effect is __?__
when a new population is established from a small number of "founders"
The founder effect results in __?__ and __?__.
different allele frequencies in founder populations
low variation in founder population
Author
p.reilly1227
ID
77615
Card Set
Genetics
Description
Genetics test questions
Updated
2011-04-06T06:25:10Z
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