79 Questions
What is the primary mechanism by which alleles with reduced fitness can persist in a population?
Propagation via heterozygous genotypes
What is the term for the phenomenon where the heterozygous genotype is fitter than either homozygote?
Heterozygote advantage
What is the condition in which a missense mutation in the β-globin gene leads to the production of abnormal hemoglobin?
Sickle-cell anaemia
What is the condition required for the maintenance of Hardy-Weinberg equilibrium?
Random mating
What is the geographic distribution of the sickle-cell anaemia allele (HbS) strongly correlated with?
Malaria endemicity
What is the Hardy-Weinberg theorem in the context of a single gene with two alleles?
An equation that describes the relationship between allele frequencies and genotype frequencies.
What is the consequence of a population not being in Hardy-Weinberg equilibrium at a particular genetic locus?
Microevolution is occurring at that genetic locus.
What is the definition of evolution from a population genetics perspective?
A change in the population's allele or genotype frequencies over time.
What is the frequency of the normal homozygous individuals in a population, assuming the Irish population is in HWE at the CFTR genetic locus?
p^2
What is the purpose of the Hardy-Weinberg theorem in the context of predicting the incidence of inherited disease?
To estimate the frequency of a genetic disorder in a population.
What is the frequency of the AA genotype in a population at Hardy-Weinberg equilibrium?
$p^2$
Cystic fibrosis is an autosomal recessive disorder. What is the genotype of an individual who is a carrier of the disease?
Aa
A population is in Hardy-Weinberg equilibrium. If the frequency of the A allele is 0.6, what is the frequency of the a allele?
0.4
The Hardy-Weinberg theorem can be used to predict the incidence of inherited diseases. What is the frequency of the aa genotype in a population where the frequency of the a allele is 0.2?
0.04
What is the relationship between the allele frequencies p and q in a population at Hardy-Weinberg equilibrium?
p + q = 1
What is the frequency of the Fy0 allele in African populations?
~1.0
What is the effect of diploidy on genetic variation in a population?
Hides genetic variation from natural selection
What is the effect of balancing selection on genetic variation in a population?
Preserves genetic variation
What is the susceptibility to malaria associated with the Fya allele?
Susceptibility
What is the role of natural selection in shaping a population's genotype frequencies?
Eradicates genetic variation
What is the reason for the increased frequency of the RP allele in Tristan da Cunha compared to Britain?
Founder effect and genetic drift
What is the effect of gene flow between populations on their genetic structure?
Reduces differences in genetic structure
What is the result of gene flow from population 1 (fixed for the a allele) to population 2 (fixed for the A allele)?
Population 2 becomes polymorphic for both alleles
What is the purpose of the Hardy-Weinberg theorem in predicting the incidence of inherited disease?
To predict the frequency of a disease-causing allele
What is the effect of inbreeding on the genotype frequencies in a population?
The frequency of heterozygotes decreases, while the frequency of homozygotes increases
In the context of the Hardy-Weinberg theorem, what is the effect of self-fertilisation on the allele frequencies?
The allele frequencies remain unchanged
What is the minimum number of generations required to observe the effects of genetic drift in a small population?
Multiple generations, depending on population size
What is the primary assumption of the Hardy-Weinberg theorem regarding population size?
The population is very large, ideally infinite
Which of the following conditions is NOT required for the maintenance of Hardy-Weinberg equilibrium?
The population is in genetic drift
What is the likely outcome of the founder effect on the genetic makeup of a new colony?
Reduced genetic variation
What is the reason for the lack of diversity at the major histocompatibility complex (MHC) genetic locus in cheetahs?
Bottleneck effect
What is the probability of being affected by Retinitis Pigmentosa (RP) in the Tristan da Cunha population?
q2 = 0.017; q = 0.13
What is the frequency of the allele associated with Retinitis Pigmentosa (RP) in Britain?
q = 0.016
What is the term for the phenomenon where a few individual organisms colonise a new habitat?
Founder Effect
What is the likely consequence of a population experiencing a bottleneck effect?
Reduced genetic variation
What is the condition caused by mutations in the rhodopsin gene (RHO) on HSA3?
Retinitis Pigmentosa (RP)
What is the effect of the founder effect on the genetic variation of a population?
Reduced genetic variation
What is the probability of being a carrier of the allele associated with Retinitis Pigmentosa (RP) in Tristan da Cunha?
q = 0.13
What is the term for the phenomenon where a population experiences a severe reduction in size, leading to a loss of genetic variation?
Bottleneck Effect
What is the probability of being a carrier of an autosomal recessive disease in a population where the frequency of the recessive allele is 0.4?
0.48
In a population at Hardy-Weinberg equilibrium, if the frequency of the AA genotype is 0.36, what is the frequency of the A allele?
0.6
What is the genotypic frequency of individuals affected by an autosomal recessive disease in a population where the frequency of the recessive allele is 0.2?
0.04
In a population at Hardy-Weinberg equilibrium, if the frequency of the A allele is 0.7, what is the frequency of the Aa genotype?
0.42
What is the purpose of the Hardy-Weinberg theorem in the context of predicting the incidence of inherited disease?
To predict the genotype frequencies of the disease in a population
What is the probability of an individual being homozygous recessive for the RP allele in a population where the frequency of the RP allele is 0.7?
0.49
In a population at Hardy-Weinberg equilibrium, what is the frequency of the heterozygous genotype if the frequency of the A allele is 0.8 and the frequency of the a allele is 0.2?
0.32
What is the effect of gene flow on the genotype frequencies in a population that was previously fixed for the a allele?
Increase in the frequency of the Aa genotype
In a population at Hardy-Weinberg equilibrium, what is the frequency of the Aa genotype if the frequency of the A allele is 0.9 and the frequency of the a allele is 0.1?
0.18
What is the effect of genetic drift on the allele frequencies in a population that has undergone a bottleneck effect?
Random change in the allele frequencies
What is the primary reason why natural selection does not eliminate genetic variation in a population?
Diploidy and genetic drift
What is the expected frequency of the Fy0 allele in a population where malaria disease persists?
p = 1.0
What is the effect of balancing selection on genetic variation in a population?
Preserves genetic variation
What is the role of diploidy in preserving genetic variation in a population?
Diploidy hides genetic variation from natural selection
What is the purpose of the Hardy-Weinberg theorem in predicting the incidence of inherited disease?
To predict the incidence of inherited disease in a population
What is the consequence of a deviation from Hardy-Weinberg Equilibrium in a population?
Microevolution is occurring at the genetic locus.
What is the probability of being a carrier of cystic fibrosis in the Irish population if the frequency of the mutated CFTR allele is 0.2?
0.48
If the frequency of the normal CFTR allele is 0.8, what is the frequency of heterozygous carriers in the Irish population?
0.48
What is the requirement for the Hardy-Weinberg theorem to be applicable to a population?
The population must be randomly mating.
What is the consequence of a change in the allele frequencies in a population over time?
Evolution is occurring.
What is the genotype frequency of Aa in a population at Hardy-Weinberg equilibrium, if the frequency of the A allele is 0.4 and the frequency of the a allele is 0.6?
0.24
In a population, the frequency of the sickle-cell anaemia allele (HbS) is 0.2. What is the frequency of the AA genotype?
0.04
What is the effect of inbreeding on the genotype frequencies in a population?
Increases the frequency of homozygotes
What is the probability of being affected by sickle-cell anaemia in a population where the frequency of the HbS allele is 0.2?
0.04
What is the condition required for the Hardy-Weinberg theorem to be applied?
Random mating and no genetic drift
What is the expected frequency of the Aa genotype in a population that is in Hardy-Weinberg equilibrium, if the frequency of the A allele is 0.5?
0.50
A population is in Hardy-Weinberg equilibrium, with allele frequencies p = 0.7 and q = 0.3. What is the expected frequency of the AA genotype?
0.49
A population is not in Hardy-Weinberg equilibrium due to inbreeding. What is the expected effect on the genotype frequencies?
A decrease in the frequency of heterozygotes
What is the condition required for the maintenance of Hardy-Weinberg equilibrium?
A very large population size, isolation, no mutations, no natural selection, and random mating
What is the application of the Hardy-Weinberg theorem in predicting the incidence of inherited disease?
To predict the frequency of affected individuals in a population
What is the genotype frequency of individuals affected by Retinitis Pigmentosa in Tristan da Cunha?
q2
What is the allele frequency of the allele associated with Retinitis Pigmentosa in Tristan da Cunha?
0.13
What is the effect of the bottleneck effect on the genetic variation of a population?
Decreases genetic variation
What is the probability of being a carrier of the allele associated with Retinitis Pigmentosa in Tristan da Cunha?
pq
What is the expected genotype frequency of the AA genotype in a population at Hardy-Weinberg equilibrium, if the frequency of the A allele is 0.7?
0.49
What is the expected allele frequency of the a allele in a population at Hardy-Weinberg equilibrium, if the frequency of the A allele is 0.6?
0.4
What is the consequence of a population not being in Hardy-Weinberg equilibrium at a particular genetic locus?
The population is not in genetic equilibrium
What is the purpose of the Hardy-Weinberg theorem in predicting the incidence of inherited disease?
To predict the incidence of inherited disease
What is the likely consequence of a population experiencing a bottleneck effect?
Decrease in genetic variation
What is the term for the phenomenon where a few individual organisms colonise a new habitat?
Founder Effect
Test your understanding of the Hardy-Weinberg theorem, which describes the frequencies of alleles and genotypes in a population. Learn how to predict genotype frequencies from allele frequencies and understand the concept of Hardy-Weinberg Equilibrium. This quiz is part of the ANSC20010 Genetics and Biotechnology course, Section 5, Spring Trimester 2023-24.
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