Bio - Chapter 20 - genes within population (a)
natural selection
antibiotic resistance is an example of
the founder effect
the changes in allele frequencies that occur due to colonization of a new location by small group of individuals is called
false
true or false: mutation and gene flow are equally important in determining how allele frequencies change
genetic variation in a population
What did Hardy and Weinberg explain?
dissassortative mating
a type of nonrandom mating where phenotypically different individuals mate
intermediate
according to the theory of blending inheritance, offspring were expected to be phenotypically ______ relative to their parents, which confused scientists originally because variation would be diluted
allele frequencies
as a result of natural selection, the _____ , ______ of genes change over time
p + q = 1
for a gene with two alleles, what equation represents the sum of all allele frequencies
exhibit variations
in natural population, most genes
are likely to increase reproduction
natural selection favours characteristics that confer a survival advantage because these traits
adaption
natural selection results in ______ in a population
preventing binding to its target enzyme
resistance allele at a single gene in Norway rats diminishes the effectiveness of the pesticide, warfarin by
1. they are single based differences 2. more than 3 million have been noted in the human genome
select all the following that is true about SNPs
1.allele frequencies are changing between generation 2.genotype frequencies do not match those predicted by the hardy-weinsberg equation based on existing allele frequencies
select the observation that would indicate that a population is deviated from hardy-weinberg equilibrium
true
true or false: generic drift, mutations and nonrandom mating are three agents that can act to produce evolutionary changes in a population
false
true or false: natural selection is the same as evolution
1. so few individuals contribute to the next generation 2. small populations are sensitive to genetic drift 3. the gene pool of the surviving members of the population may be different from the original
3 reasons for population bottleneck
small
although random changes in allele frequencies can occur due to chance events when populations are of any size, the changes are most likely to be obvious when population size is
colouration
an adaption that allows the larvae of the butterfly to avoid predators is the______ of the caterpillar (pg 404)
0.64 AA, 0.32 Aa, 0.04 aa
consider a gene in a population of fruit bats. There are two alleles for this gene, A and a at 0.8 and 0.2. What is the genotype frequencies observed
0.84
consider a population with 100 cats. If 84 cats are black and 16 are white, what is the phenotypic frequency of black cats
location of the population
enzyme allele frequencies within a population may vary based on
genetic
evolution can result from any process that changes the ___ composition of a population
1. migration 2. natural selection 3. mutations
evolutionary change within a population can result from which of the following
1. reduce evolutionary change 2. remove alleles from the population 3. promote evolutionary change 4. introduce new alleles to a population
gene flow may
allele frequencies
genetic variation in a population results from evolutionary forces that cause _____ to change
unchanged
if a population is in Hardy- Weinberg equilibrium, allele and genotype frequency are _______ from one generation to the next
evolutionary
if a population is not in Hardy-Weinberg equilibrium then ________ processes are operating
evolution
if a population is not in hardy- weinberg equilibrium then ______ processes are operating
0.7
if the frequency of allele b in a population is equal to 0.7, then the frequency, with which a gamete will carry allele b is equal to_________ if the population is in Hardy-Weinberg equilibrium
0.18
in a population of painted turtles a dominate allele for a certain trait occurs at a frequency of 0.1. If this population is in Hardy-Weinberg equilibrium, what would be the expected heterozygotes
0.16
in a population of tree frogs the observed frequency of GG,Gg,gg genotype is 0.1,0.6,0.3. If the population was in Hardy-Weinberg equilibrium, what would the expected GG?
enzyme , geographic
mummichog fish have variable _______ allele frequencies according to their _________ location
genetics
natural population exhibits significant ______ and pheonotypic variation
selection for individuals resistant to pesticide as we increased pesticide use
pesticide resistance has rapidly evolved because
alternative alleles of genes encoding enzymes
protein electrophoresis gels can be used to distinguish which of the following
allele, alleles
the allele frequency is calculated by dividing the number of copies of a given ______ in a population by the total number of ________ in that population.
natural selection
the process in which beneficial traits that are heritable become more common in successive generations is called
natural selection
the theory of ________, __________ proposes that the variation among individuals is not created by experience, but is the result of pre-existing genetic differences
likely to be lost
what can likely happen to uncommon alleles in small,isolated populations as a result of genetic drift
1. the population of heterozygotes in the population decreases 2. the proportion of homozygotes increases
what can result from assortative mating
1. harmful alleles may increase in frequency 2. beneficial allele may increase 3. favourable alleles may be lost
what can result from genetic drift
genetic variation will decrease
what changes in genetic variation in a population are expected after a bottleneck then growth then return to original population size
genetic drift
what evolutionary mechanism results in random changes in allele frequencies from one generation to the next
the relative likelihood that a genotype will contribute to the gene pool of the next generation
what is fitness
the movement of allele into or out of a populaton
what is gene flow
random changes in the allele frequencies of a population over time
what is genetic drift
the study of the properties of genes in population
what is population genetics
mutation
what is the ultimate source of genetic variation (pg 401)
1. a moth that has gene for cryptic coloration 2. a plant with an enzyme that makes it disease-resistant
what reasons could cause evolutionary change by natural selection
1.Darwin thought that selection should always favour an optimal form 2.segregation of alleles among progeny of hybrids was not understood 3. genetic variant were expected to dilute if hybrid offspring were intermediate to adults
what was a reason that puzzled Darwin and others regarding genetic variation
assortative mating
which evolutionary mechanism changes genotype frequencies but does not change allele frequencies
directional selection
which type of selection acts to eliminate individuals at one extreme of a phenotypic range