Term
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Definition
changes in DNA bease sequence pairs that cause changes in aa sequence |
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Term
transition vs transversion |
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Definition
transition: purine to a purine (A for G)
transversion: purine for pyrimidine and visa versa (A for T) |
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Term
synonymous vs nonsynonymous mutation |
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Definition
synonymous is when there is no ultimate change in amino acid sequence due to genetic redundancies
nonsynonymous is when there is a change in aa sequence |
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Term
frame-shift mutation
two types |
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Definition
when either a removed or added base effects the reading from of the gene.
two types are insertion and deletion |
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Term
Explain how when looking across the range of one species, continuous phenotypes might give the impression of existence of discrete phenotypes |
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Definition
You could be observing a polytypic triat.
Geographically, in two separate locations you see what looks like discrete phenotypes. However if you look in the intergrade zones (between the discrete areas) you may see intermediate phenotypes. |
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Term
What's the experiemental equation for Vp? |
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Definition
Vp = √[(ΣYi-Ȳi)2/(n-1)]
Yi equals each measurement
Ybar = mean
n= number of measurements |
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Term
Calculate Vp for tibia length for each population given these numbers:
Popn 1: .5, 1.8, 1.5, 2, 3.5, 3, 3.5, 2.5, 1.6, 1.8, 1.9, 2.1, 2.2, 2.7, 2.9
Popn 2: 1, 1.5, 2, 2.9, 3.7, 3.5, 4, 1.7, 2.3, 2.6, 3.4, 2.8, 3.7, 3.4, 3.9
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Definition
Avg-Popn 1: 2.23
Avg-Popn: 2.83
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Term
What are the possible genetic and non-genetic contributions to Vp? |
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Definition
Genetic
Va Additive variance, Vgxe genetic by environment, Vi epistatic
Non-genetic
Ve Environmental/Proximate/Unexplained, |
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Term
Propose a hypothesis that explains the evolution of tibia length between two popn of lizards. On epop lives in ares that are effectively hunted by hawks. The popn here needs to run fast. The other lives in a grassy area and burrows. The open-area lizards have long tibias and the grassy lizards have short tibias with muscular legs. |
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Definition
Tibia length is positively correlated with leg length which is positively correlated with speed and negatively correlated with digging power. Sooo our hypothesis is:
There is a selective benefit to having long tibias in open areas and to having short tibias in grassy areas, and therefore a population in either given location will not be in HWE. |
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Term
Define the different contributors to Vp |
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Definition
Environemtal (Ve): the portion on Vp that isi due to random, environmentally induced variation among induviduals. ex. energy acquisition or sampling bias
Epistatic (Vi): interaction between two or more loci in which the experssion of one of more is modified (ex. albino mice)
Gene by Environment (Vgxe): variable eniveronment cues that affect the expression of genes as well as neural and hormonal mechanisms
Additive (Va): variability in a trait due to the effects of several alleles at a diff loci that add to a background value |
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Term
Consider a diallelic locus.
After a single gen of mating, determine the mathematical relationship between allele and genotype frequencies. |
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Definition
p2+ 2pq+q2 =1
where p is the frequency of A
q is the frequency of a
p2 is the frequency of AA
2pq is the frequence of Aa
q2 is the frequncy of aa |
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Term
So you have a popn in HWE with that damn equation holding true. Derive what the allele frequencies will be in HWE. |
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Definition
We know the frequencies of all the genotypes:
AA = p2
Aa = pq for each of Aa and aA=2pq
aa= q2
We know how to mathematically find an allele frequency for A. It is the frequency of the homogenous + 1/2 the heterogenous. So: freq of A= p2 + pq. This can be simplified as p(p+q). We know p+q = 1 by addition rule. So therefore freq of A= p.
Then we do the same for q. |
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Term
Guppies live in enviros with predators that like large spot size. But, femails select males that have large spots too. Some ppl count spot size in guppies (its incompletely dominant) where SS is lrge, Ss is intermediate and ss is small. SS=53, Ss=24, ss=23
1. Determine p and q
2. Determine expected HW frequencies
3. Plot that on a HWE graph. Should fit in. Seem good?
4. Determine the expected HW counts
5. State the null hypothesis
6. determine if it can be rejected. |
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Definition
1. p is going to equal the p2 value + .5(2pq)
p=.53 + .5(.24)
p=.65
same process works for q.
q=.35
2. SS= .652= .422
Ss= 2pq=2(.65)(.35)=.455
ss=.352 =.122
3. Looks good!
4. SS: .422*100=42.2
Ss: .455*100=45.5
ss: .122*100=12.2
5. Observed frequencies are the same as expected frequencies in HWE. There is no difference between these values.
6. we solve for x2=sum of [(observed-expected)2/expected]=22.48 REJECT
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Term
For two unlinked diallelic loci, give the expected HW genotypes
(C1C2 D1D2) |
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Definition
Each loci have their own p2+2pq+q2 equation that describes them.
C1C1D1D1
C1C1D1D2
C1C1D2D2
C1C2D1D1
C1C2D1D2
C1C2D2D2
C2C2D1D1
C2C2D1D2
C2C2D2D2
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Term
For two linked diallelic loci give the expected HW genotypes. |
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Definition
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Term
For two linked, diallelic loc (C1C2 and D1D2), what are the HW genotypes? |
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Definition
Same as linked....I think. |
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Term
What's the difference between a discrete population, subpopulation and metapopulation? |
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Definition
discrete populations are distinctly different and genes dont move between them.
a metapopulation is a popn with little sub popns in it that can interbreed/have genes move across them. |
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Term
What are the models of gene flow? |
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Definition
continent island (dispersal is peripheral unidirection)
island (dispersal is random among popn)
stepping stone (dispersal is linear
isolation by distance (limited gene flow in a continuous distribution that result in a genetically differentiated individuals that are distantly separated) |
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Term
three alleles exist at a single locus: B1, B2 and B3. In general terms, give the genotype freq expected under HWE |
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Definition
freq of B1= p
freq of B2=q
freq of B3=r
p2+2pq+q2+2qr+r2+2pr=1
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Term
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Definition
Coefficient of Disequilibrium
= (p1q1 x p2q2) - (p1q2 x p2q1)
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Term
Do number 11 on the study guide. |
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Definition
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Term
Explain how and why linked loci vary among populations of the Batesian mimc Papilio mimnon. In your answer explain the term "super gene." |
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Definition
In the case of papilio memnon, linkage-disequilibrium results from NS on allelic combos.
Papilio memnon is a SE Asian butterfly that has geogrphic phenotypic variation. It is a non-toxic (Batesian) mimic of other toxic butterflies.
Wing shape, color and pattern are determined by several linked loci, most of which have multiple alleles. The different discrete morphs have different genotypes. In a given area these big sets of linked loci are selected on and act like a "supergene" allowing the mimic to adapt to match the local model.
Intermediates are not seen b/c they are recognized by predators. |
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Term
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Definition
Effective population size |
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Term
Determine Increase, Decrease, No Change (I, D, NC) in rate of random genetic drift for the following:
a. change in mutation rate from .001 to .000001 per gamete per generation
b. an increase in the rate of migration into a popn
c. a change in Ne from 600 to 150
d. An increase in the rate of selfing in a popn of plants
e. The establishment of "local neighborhoods" within a popn |
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Definition
a. I (mutation slows RGD)
b. I
c. I
d. I
e. I
look in book |
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Term
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Definition
Heterozygosity (H)
= 1-Σpi2
where pi is the frequency of each allele.
and avg H (Hbar)
avg freq of heterozygotes (H) across all loci |
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Term
Describe RGD, Founder Effect, and Genetic Bottleneck |
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Definition
RGD: Alleles that establish the next generation are assumed to be a random sample from parental gene but are really not due to sampling bias as well as random drift of the frequency of a given allele
Founder Effect: a genetic drift like process. Founders are individuals that form a new popn and the genetic composition of the new popn is thus a subset of the parent popn
Genetic Bottleneck: another genetic drift like process. a rapid decrease in popn size and thus a big decrease in genetic variation |
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Term
Redlegged frogs have been reduced to small popn with numbers of breeding adults as low as 12 individuals. What potential problem exists for such small populations? Outline two measures that you would take to maintain this population? |
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Definition
1. this could lead to inbreeding and a decrease in the overall genetic exchange. Not only will the effective population decrease, but also mortality may increase while vitality may decrease in the offspring.
2. a. try to decrease inbreeding among populations
b. introduce individuals from one small population to another population to promote genetic variation.
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Term
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Definition
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Term
When Nm is low, what happens to RGD? |
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Definition
RGD often ends up genetically differentiating amon populations. |
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Term
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Definition
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Term
What is population fragmentation?
What's one type of it? |
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Definition
reduction of a single popn into several smaller popn
Range retraction: when a geographically widespread popn becamoes smaller populations |
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