Exam 2 and quiz 2

ON which chromosome is mysosin 9 gene located?

Chromosome 10

Which doegs have more hound-breed influence?

Sprint dogs

What are two racing purposes for alaskan sled dogs?

Distance or sprint

What type od dogs are alaskan sled dogs?

Mixed breed

New breeds can sometimes result from mixing existing breed T or F

True

Maternal Cross Primary goal

Better replacment cow

Terminal Cross Primary goal

Better market cow

Breed complementarity Primary goal

New trait combinations

Cross breeding Primary goal

Allele Migration

WHat traits are emphasized in a terminal cross?

Muscle or growth

What is breed complementarity?

New trait combinations

In population-genetic terms, cross breeding is a form of what?

Allele Migration

What does cross breeds introeuce between populations?

New alleles

What does it mean if an animal is free of a harmful hapotype?

Homozygous for a better haplotype

What does it mean if an animal carries a haplotype?

Its heterozygous

What do diary cattle genetic evaluations report for evaulated haplotypes?

Carrier status

Which Haplotype is associated with healthy individuals in the example?

TCA

In the lecture example, which haplotye is associated with musclar weakness in homozygous individuals?

CAG

Why may genotyping fail yo identify the exact mutuation causing a phenotype?

The mutation is unknown

T OR F Selection on one allele can indirectly select linked alleles

true

What process can separate favorable and harmful linked alleles?

Recombinations

What can a harmful allele do to a favorable allele?

hitchhike along

What is a haplotype?

Adjacent Alleles that are inherited together

What happens when one allele is slected and nearby alleles are linked to it?

They are selected too

What evolutionary pattern is limited in a closed purebred population?

Migration

What does a closed purbred population prohibit?

New animals entering

What may happen to traits during repeated directional artifical selection?

They become extreme

What happens to favorable traits over generations of breed formaton?

They become consistent

What effect occurs when a breed begins with a few founder animals?

The founder affect

What does a breed standard describe?

The ideal animal

Who created the first standardized breed mentioned in the lecture

Robert Blackwell in 1850

What is a breed?

An interbreeding animal group

What happens when animals with a desired phenotype are selected repeatedly?

Related allele frequencies

T OR F natural selection can still affect animals in a selection-breeding system

True

In selective breeding, who decided which animals can reproduce

humans

What is artifical selection also called?

Selective breeding

What genotype has a higher fitness in overdominance?

Heterozygote

What happens to alelle frequencies at stabilizing selection equilibrium?

They stop changing

What phenotype does stabilizing selection favor?

Intermediate phenotypes

Under directional selection, what can eventually happen to the favored allele?

Fixation

If ‘A’ is favored, what happens to the A2 allele?

Frequency decreases

If A is favored, what happens to its allele frequency?

It increases

What characterizes directional selection?

One phenotype is favored

Selection coefficient is calculated by

s=1-W

Relative fitness is represented by

W

Fitness is measured relative to what genotype

most prolific genotype

What is fitness in evolutionary genetics?

Reproductive success

What two patterns can selection produce in allele frequencies?

Directional and stabilizing

What type of selection is driven by human prefreence?

Artifical selection

What type of selection is driven by environmental conditons?

Natural selection

What genetic pattern can produce stabilizing selection?

Overdominance

What is the fitness relationship in overdominance?

Heterozygote is fittest

Stabilizing selection makes allele frequencies equal T OR F

False

Why can selection change allele frequencies?

Phenotypes depend on genotypes

What is the Hardy-Weinberg frequency of the homozygous recessive genotype?

q²

What is the Hardy-Weinberg frequency of the heterozygous genotype?

2pq

What is the Hardy-Weinberg frequency of the homozygous dominate genotype?

p²

Under Hardy-Weinberg equilibirum, what determines genotype frequencies?

Allele frequencies

What does stabilizing selection favor?

Intermediate phenotypes

what may eventually happen to the favored allele under directional selection

fixation

Under directional selection, the allele for the favored phenotype increases in frequency

true

What happens during directional selection

One phenotype is favoted

What is the formula for selection coefficent?

s = 1- W

What symbol represents the selection coefficient in s = 1- W

S

What does the selection coefficient measure in s = 1- W

Selection intensity

What symbol represents fitness in s = 1- W

W

Relative fitness is measured against what phenotype?

Most prolific genotype

What is fitness?

Reproductive success

What does selection directly act on?

Phenotypes

What type of selection results from human prefrence?

Artificial selection

What determines which phenotype are more likely to reproduce?

Selection

Why can alleles from a popular sire dominate a population?

If the sire is used heavily

What is the popular sire effect similar to?

Founder effect

Why does the founder effect produce low effective population size?

Few individuals establish population

What IS the founder effect

A new population from few individuals

T OR F alles can be lose during genetic bottle neck

True

What can happen to alle frequencies after a bottle neck?

They can differ completely from the original

What is a genetic bottle neck?

Drastic population reduction

What can continually reduce effective population size over many generations?

Gradual population reduction

What demographic factor can affect effective population size?

Sex ratios

Effective population size is usually smaller than census population size

True

What does effective population size measure?

Breeding adults contributing genes

What population measure affects the magnititude of genetic drift?

Effective population size

What is fixation

Allele frequency of 1

What outcomes can result form genetic drift

Reduced genetic diversity, allele fixation, allele loss

What causes genetic drift?

Chance

What is genetic drift?

Random allele-frequency change

What happens to genetic variation within a population when alleles immigrate

it increases

What process introduces alleles through immigration

Migration

What is migration in population genetics?

Allele movement between populations

T OR F a mutation that affects phenotype can subsequent;y be acted on by selection

true

What can a mutation create or alter?

Alleles

What is mutation at the population genetic level?

Nucleotide sequence change

Why can a population in HWE not evolve?

Allele frequencies do not change

Being in HWE means that the two allele frequencies must be equal

false

What happens to the equilibirum if allele frequencies have changes?

A new equilibrium

T OR F HWE can be re-established after random mating even if other assumptions are violated

fasle

What determines genotypic frequencies under HWE?

Allele Frequencies

A population can be in HWE at one locus but not at other locus T OR F

True

How many loci does HWI apply to at one time

One locus