EEOB 3310 Exam 3 Questions With
Correct Answers
Assumptions |of |Hardy |Weinberg |- |CORRECT |ANSWER✔✔-No |natural |selection
Mating |is |random
Large |population |size
Mutation |and |migration |are |negligible |(no |new |alleles)
Random |Sampling |- |CORRECT |ANSWER✔✔-A |sample |that |fairly |represents |a |population |
because |each |member |has |an |equal |chance |of |inclusion
A |larger |population |will |more |accurately |reflect |the |population |values
The |primary |effect |of |small |populations |is |to |introduce |sampling |error |(when |the |sample |
doesnt |reflect |the |population |accurately)
Sampling |Error |- |CORRECT |ANSWER✔✔-Produces |random |changes |in |allele |and |genotype |
frequencies
Evolution |can |occur |but |it |is |indirected |and |unpredictable |for |any |given |situation |
Two |different |populations |will |have |trajectories |of |genetic |change |due |to |sampling |error
Given |long |enough, |the |process |inevitable |leads |to |fixation |of |one |allele
Genetic |Drift |- |CORRECT |ANSWER✔✔-The |process |of |random |genotypic |and |allelic |functions |
due |to |sampling |error
Has |the |strongest |effect |in |small |populations
A |random |process |(dont |know |which |allele |will |eventually |be |fixed, |rare |alleles |most |likely |to |
be |lost)
Causes |loss |of |genetic |variation, |expected |heterozygosity |is |reduced.
Expected |heterozygosity |decreases |by |a |factor |of |1/2 |N |each |generation |(N |is |population |size)
, He=1-(p2+q2+r2)
He'=He(1-(1/2N)) |As |population |goes |up, |the |fraction |gets |smaller, |meaning |we |would |be |
closer |to |keeping |the |original |heterozygosity |over |time |if |the |population |is |large
Population |size |factors |could |also |be |competition |for |mates |(only |a |couple |males |take |most |of |
females), |or |unequal |number |of |males |and |females, |or |fluctuating |population |sizes
Effective |Population |Size |- |CORRECT |ANSWER✔✔-Ne
The |effects |of |genetic |drift |depend |on |the |effective |population |size
Ne |is |always |smaller |than |the |actual |number |of |individuals
Ne=(4NmNf)/(Nm+Nf)
The |"march |to |homozygosity" |- |CORRECT |ANSWER✔✔-If |alleles |are |selectively |neutral, |
population |will |eventually |drift |to |homozygosity
Evolution |has |occurred |by |random |process
Coalescence |- |CORRECT |ANSWER✔✔-Working |backwards |in |time, |we |can |trace |all |present |
alleles |back |to |a |single |ancestral |allele |(the |coalescent)
Every |gene |in |every |species |traces |back |to |a |single |coalescent
Ex. |Mitochondrial |Eve |(maternal |line) |and |Y-chromosomal |Adam |(paternal |line)
Nuclear |DNA |is |inherited |from |all |ancestors, |mitochondrial |DNA |is |inherited |from |a |single |
lineage
Genetic |Drift |in |Nature |- |CORRECT |ANSWER✔✔-In |chronically |small |populations |(rare |or |
endangered |or |threatened |species)
Population |bottlenecks |(rapid |decline |in |population |size)
Founding |Populations: |the |Founder |Effect
Correct Answers
Assumptions |of |Hardy |Weinberg |- |CORRECT |ANSWER✔✔-No |natural |selection
Mating |is |random
Large |population |size
Mutation |and |migration |are |negligible |(no |new |alleles)
Random |Sampling |- |CORRECT |ANSWER✔✔-A |sample |that |fairly |represents |a |population |
because |each |member |has |an |equal |chance |of |inclusion
A |larger |population |will |more |accurately |reflect |the |population |values
The |primary |effect |of |small |populations |is |to |introduce |sampling |error |(when |the |sample |
doesnt |reflect |the |population |accurately)
Sampling |Error |- |CORRECT |ANSWER✔✔-Produces |random |changes |in |allele |and |genotype |
frequencies
Evolution |can |occur |but |it |is |indirected |and |unpredictable |for |any |given |situation |
Two |different |populations |will |have |trajectories |of |genetic |change |due |to |sampling |error
Given |long |enough, |the |process |inevitable |leads |to |fixation |of |one |allele
Genetic |Drift |- |CORRECT |ANSWER✔✔-The |process |of |random |genotypic |and |allelic |functions |
due |to |sampling |error
Has |the |strongest |effect |in |small |populations
A |random |process |(dont |know |which |allele |will |eventually |be |fixed, |rare |alleles |most |likely |to |
be |lost)
Causes |loss |of |genetic |variation, |expected |heterozygosity |is |reduced.
Expected |heterozygosity |decreases |by |a |factor |of |1/2 |N |each |generation |(N |is |population |size)
, He=1-(p2+q2+r2)
He'=He(1-(1/2N)) |As |population |goes |up, |the |fraction |gets |smaller, |meaning |we |would |be |
closer |to |keeping |the |original |heterozygosity |over |time |if |the |population |is |large
Population |size |factors |could |also |be |competition |for |mates |(only |a |couple |males |take |most |of |
females), |or |unequal |number |of |males |and |females, |or |fluctuating |population |sizes
Effective |Population |Size |- |CORRECT |ANSWER✔✔-Ne
The |effects |of |genetic |drift |depend |on |the |effective |population |size
Ne |is |always |smaller |than |the |actual |number |of |individuals
Ne=(4NmNf)/(Nm+Nf)
The |"march |to |homozygosity" |- |CORRECT |ANSWER✔✔-If |alleles |are |selectively |neutral, |
population |will |eventually |drift |to |homozygosity
Evolution |has |occurred |by |random |process
Coalescence |- |CORRECT |ANSWER✔✔-Working |backwards |in |time, |we |can |trace |all |present |
alleles |back |to |a |single |ancestral |allele |(the |coalescent)
Every |gene |in |every |species |traces |back |to |a |single |coalescent
Ex. |Mitochondrial |Eve |(maternal |line) |and |Y-chromosomal |Adam |(paternal |line)
Nuclear |DNA |is |inherited |from |all |ancestors, |mitochondrial |DNA |is |inherited |from |a |single |
lineage
Genetic |Drift |in |Nature |- |CORRECT |ANSWER✔✔-In |chronically |small |populations |(rare |or |
endangered |or |threatened |species)
Population |bottlenecks |(rapid |decline |in |population |size)
Founding |Populations: |the |Founder |Effect
