GEN EXAM 2 QUIZZES Flashcards
Which of the following is NOT an assumption of the Hardy-Weinberg equation
A. The population is large
B. There is nonrandom mating
C. There is no mutation in the gene being studied
D. There is no migration into or out of the population
E. There is no selection against a given genotype
B. There is nonrandom mating
The formula p^2 + 2pq + q^2 = 1 is associated with which of the following
A. calculations of heterozygosity
B. Hardy-Weinberg equilibrium
C. calculations of recombination frequencies
D. degrees of freedom
E. None of these choice are correct
B. Hardy-Weinberg equilibrium
Given a population of 1,000 individuals what is the average number of generations it will take to fix a new mutation assuming no selection for or against the new mutation?
A. 4,000
B. 100,000
C. 1,000
D. 25,000
A. 4,000
What is the probability of fixation of a gene in a population of 30 individuals (assume no selection for or against a mutation)?
A. 3.3%
B. 3%
C. 0.167%
D 1.67%
D 1.67%
Given the allele frequency for a gene in population A is 0.3 and the frequency for the same alleles in population B is 0.5 and that 25 individuals from A migrate to and mate randomly with the 475 individuals in population B, what is the new allele frequency (P_C) in the conglomerate?
A. 0.2
B. 0.49
C. 0.052
D. 0.8
B. 0.49
Consider a hypothetical gene B for which there are two alleles in the population. For every ten BB individuals that survive, six Bb individuals survive, and one bb individual survives. What are the relative fitness values for each genotype?
A. wB = 26; wb = 7
B. wBB = 0.59; wBb = 0.35; wbb = 1.0
C. wBB = 100; wBb = 0.6; wbb = 0.01
D. wBB = 1.0; wBb = 0.6; wbb = 0.1
D. wBB = 1.0; wBb = 0.6; wbb = 0.1
The prevalence of the allele for sickle cell anemia in some populations is an example of which of the following?
A. balancing selection
B. non-Darwinian selection
C. nonrandom mating
D. heterogenous environments
E. inverted selection
A. balancing selection
The term for the mating for two genetically unrelated individuals is
A. disassortative mating
B. inbreeding
C. outbreeding
D. assertive mating
C. outbreeding
Microevolution is defined as
A. changes in gene flow from one generation to the next
B. morphological changes that occur from one generation to the next
C. changes in the gene pool from one generation to the next
D. the ability of different genotypes to succeed in a particular environment
C. changes in the gene pool from one generation to the next
You are preparing to perform DNA fingerprinting by PCR for the first time. Select the reagent that would result in complications in the interpretation of your results.
A. PCR primers that anneal to regions flanking the microsatellites
B. Taq polymerase
C. Human DNA
D. PCR primers that anneal to the repetitive region of the microsatellites
D. PCR primers that anneal to the repetitive region of the microsatellites
Heritability may be calculated as which of the following?
A. the total variance minus environmental variance
B. total variance minus genetic variance
C. genetic variance divided by environmental science
D. genetic variance divided by total variance
E. None of these choices
D. genetic variance divided by total variance
Calculate the narrow sense heritability for a grandparent-grandchild relationship when the observed correlation coefficient is 0.2.
A. 0.8
B. 2.5
C. 0.4
D. 1.25
A. 0.8
What must be true regarding the strains of organisms used to construct a QTL map?
A. they must differ for the quantitative trait
B. they must differ for the molecular markers
C. both of these choice must be true
C. both of these choice must be true
Which of the following steps is NOT used in conducting a backcross in order to map a QTL?
A. the F2 offspring contain different combinations of the parental chromosomes
B. by using genetic markers, it is determined which parent each chromosome came from and thus genes are identified
C. the F1 offspring are crossed with each other
D. two inbred strains that differ in a quantitative trait are crossed
C. the F1 offspring are crossed with each other
Quantitative traits usually have which of the following characteristics?
A. environmental influence
B. polygenic basis
C. continuous distribution
D. All of these are correct
D. All of these are correct
If the difference between the mean of the parents and the mean of the starting population is 1.0 and the difference between the mean of the offspring and the mean of the starting population is 0.45 then the realized heritability is
A. 0.45
B. 2.22
C. 0.56
D. 1.45
A. 0.45
In calculations of the degrees of freedom for a correlation coefficient, what value does the degrees of freedom take?
A. (n-1)
B. 2(n-1)
C. (n-1) / 2
D. (n-2)
D. (n-2)
After calculating a correlation coefficient, you discover that the value is not significant at the 5% level. What can be done that may result in a significant difference?
A. increase the sample size
B. decrease the sample size
C. nothing, the value will remain the same regardless of sample size
A. increase the sample size
The square root of the variance is called the _____
A. standard deviation
B. covariance
C. standard error
D. mean
A. standard deviation
Calculate the mean plant height, the variance and the standard deviation for 10 plants that have the following heights: 5 cm, 6 cm, 6 cm, 7 cm, 7 cm, 7 cm, 8 cm, 9 cm, 9 cm, and 10 cm
A. mean: 7.4 cm, variance: 2.5 cm^2; standard deviation: 1.6 cm
B. mean: 7.5 cm, variance: 3.5 cm^2, standard deviation: 1.6 cm
C. mean: 7.4 cm, variance: 2.5 cm^2, standard deviation: 1.9 cm
D. mean: 7 cm, variance: 3.5 cm^2, standard deviation: 1.9 cm
A. mean: 7.4 cm, variance: 2.5 cm^2; standard deviation: 1.6 cm
In a given population of Drosophila, curly wings (c) is recessive to the wild-type condition of straight wings (c+). You isolate a population of 35 curly winged flies, 70 flies that are heterozygous for straight wings, and 45 that are homozygous for straight wings. What is the frequency of alleles in this population?
A. 35% c; 45% c+
B. 46.7% c; 53.3% c+
C. 50% c; 50% c+
D. 55% c; 45% c+
E. None of these choices are correct.
B. 46.7% c; 53.3% c+
Which type of selection would lead to two distinct phenotypes?
A.disruptive selection
B.directional selection
C.phenotype selection
D.fitness selection
E.stabilizing selection
A.disruptive selection
Which of the following types of selection creates two phenotypic classes from a single original distribution?
A.disruptive selection
B.directional selection
C.phenotype selection
D.fitness selection
E.stabilizing selection
A.disruptive selection
How does inbreeding affect the Hardy-Weinberg equilibrium?
A.It makes it more likely for the population to remain in Hardy-Weinberg equilibrium.
B.It results in a higher level of either dominant or recessive homozygotes.
C.It results in a higher level of heterozygotes.
D.It has no effect on the Hardy-Weinberg equilibrium.
B.It results in a higher level of either dominant or recessive homozygotes.
By what process do new alleles arise?
A.Migration
B.Natural selection
C.Nonrandom mating
D.Mutation
E.Genetic drift
D.Mutation
Calculate the narrow-sense heritability of height between aunts and nieces if the observed phenotypic correlation coefficient is 0.1
A.2.5
B.0.25
C.4
D.0.4
D. 0.4
A heritability value of 0.997 indicates which of the following?
A.The majority of the phenotypic variation has a genetic basis.
B.The majority of the phenotypic variation has an environmental basis.
C.The trait is polygenic.
D.There is a significant difference between the two strains.
E.None of these choices are correct.
A. The majority of the phenotypic variation has a genetic basis.
QTL mapping determines the relationship between genes for quantitative traits and which of the following?
A.structural genes
B.the centromere
C.transposon sites
D.molecular markers such as RFLPs
D. molecular markers such as RFLPs
In QTL mapping, the parental strains are crossed and the F1 generation backcrossed to which of the following?
A. a wild-type organism
B. a strain that is homozygous recessive for all markers
C. the F2 generation
D. the parental generation
D. the parental generation
In a given population of Drosophila, curly wings (c ) is recessive to the wild-type condition of straight wings (c+ ). You isolate a population of 35 curly winged flies, 70 flies that are heterozygous for straight wings, and 45 that are homozygous for straight wings. What is the total number of curly or straight wing alleles in this population?
A. 2
B. 150
C. 230
D. 300
E. None of these choices are correct
D. 300
What is the frequency of an allele in a conglomerate population if 50 individuals from a population where the allele has a frequency of 0.6 migrates into a population of 450 individuals where the allele frequency is 0.3?
A. 0.3
B. 0.33
C. 0.18
D. 0.9
B. 0.33
Calculate the inbreeding coefficient of an individual given an n of 4 (excluding the inbred offspring) with one common ancestor. The inbreeding of the common ancestor is unknown.
A. 50%
B. 3.125%
C. 25%
D. 6.25%
D. 6.25%
Repetitive sequences are useful for DNA fingerprinting because they
A. are inherited and can show significant variability between individuals.
B. are not inherited and so are unique to every individual.
C. never undergo mutation.
D. are unique to every individual and change from generation to generation.
A. are inherited and can show significant variability between individuals.
Inbreeding reduces which of the following variances to near zero?
A. genetic variance
B. environmental variance
C. both variances
D. neither variance
A. genetic variance
After several generations of artificial selective breeding, a plateau is reached where artificial selection is no longer effective. This is called the _______.
A. selection coefficient
B. selection limit
C. realized limit
D. realized heritability
B. selection limit
Which of the following best describes the degrees of freedom for the calculation of variance?
A. (n - 1)
B. (n - 1)/n
C. (n + 1)
D. 2(n + 1)
A. (n - 1)
What must be true for a correlation coefficient to be calculated between two traits?
A. The values for the traits must have been obtained from unbiased sampling.
B. The relationship between the two traits must be linear.
C. The traits must follow a normal distribution.
D. All of these choices are correct.
D. All of these choices are correct.
Suppose the genes for eye color and wing shape are both on the X chromosome (they are linked) and are known to be 68 map units apart. In a mating between a Xw+m+Xwm female and a XwmY male that produces 1000 progeny, how many recombinant progeny would you expect to observe?
A. 320
B. 500
C. 340
D. 680
B. 500
The visual proof that chromosomes exchange pieces of information during crossing over was provided by __________.
A. Bateson and Punnett
B. Morgan and Bridges
C. Creighton and McClintock
D. Watson and Crick
C. Creighton and McClintock
Experimental evidence that crossing over occurs between the X chromosomes of female Drosophila was provided by __________.
A. Morgan
B. Punnett
C. Darwin
D. Bateson
A. Morgan
The diploid garden pea plant has 14 chromosomes. The haploid fungus Neurospora crassa has 7 chromosomes. Neither organism has separate male and female individuals. Therefore, the number of linkage groups in these two organisms is
A. Garden pea has 14 linkage groups, and Neurospora has 7.
B. Garden pea has 7 linkage groups, and Neurospora has 7.
C. Garden pea has 8 linkage groups, and Neurospora has 8.
D. Garden pea has 15 linkage groups, and Neurospora has 8.
B. Garden pea has 7 linkage groups, and Neurospora has 7.
Two genes that are located on the same chromosome are said to be _____.
A. linked
B. recombinant
C. parental-like
D. nonparental-like
linked
Another name for a chromosome is a _______, since it contains genes that are often inherited together.
A. linkage group
B. crossing over group
C. genetic recombinant
D. bivalent
A. linkage group
While mapping two genes in Drosophila, you observe 30 recombinants among 200 total offspring. What is the distance between these genes?
A. 30 map units
B. 6.67 map units
C. 200 map units
D. 15 map units
D. 15 map units
A testcross is always performed between the individual that is heterozygous for the genes to be mapped and an individual who is ____________.
A. Heterozygous for the genes
B. Homozygous dominant for the genes
C. Homozygous recessive for the genes
D. Lacking the genes
E. None of the answers are correct
C. Homozygous recessive for the genes
In a mapping cross, you determine that the recombination frequency between:
loci Q and P is 12%
loci Q and L is 15%.
If locus Q is in between loci P and L, then the recombination frequency between P and L should be approximately
A. 3%.
B. 27%.
C. 50%.
D. 75%.
B. 27%.
Which of the following are necessary characteristics of an organism in order to easily construct a genetic linkage map?
A. short generation times
B. produces large numbers of offspring
C. easily crossed
D. All of these choices are correct.
D. All of these choices are correct.
Twin spotting provides evidence of what genetic event?
A. mutation
B. meiotic recombination
C. linkage
D. mitotic recombination
D. mitotic recombination
Which of the following defines gene linkage?
A. Two or more genes that are physically connected on a chromosome.
B. Genes that are transmitted to the next generation as a group.
C. The process by which genetic information is exchanged between homologous chromosomes.
D. All of these choices are correct.
E. Both two or more genes that are physically connected on a chromosome and genes that are transmitted to the next generation as a group.
E. Both two or more genes that are physically connected on a chromosome and genes that are transmitted to the next generation as a group.
In humans, there are _______ autosomal linkage groups, plus an X and Y chromosome linkage group.
A. 23
B. 46
C. 92
D. 22
D. 22
Assume that genes C and D are located on the same chromosome. On one chromosome alleles C and D are found, while the homolog contains alleles c and d. Which of the following would be an example of a recombination event?
A. alleles C and D together on one chromosome
B. alleles c and D together on one chromosome
C. alleles C and d together on one chromosome
D. alleles c and d together on one chromosome
E. both alleles C and d together on one chromosome and alleles c and D together on one chromosome
E. both alleles C and d together on one chromosome and alleles c and D together on one chromosome
Creighton and McClintock worked with _____ as their model system to show that homologous chromosomes physically exchange genetic information during crossing over.
A. corn
B. fruit flies
C. tobacco
D. peas
A. corn
Crossing over is more likely to occur between genes that are ______ on a chromosome.
A. not
B. far apart
C. close together
B. far apart
The middle gene of a three gene mapping experiment can be determined by examining the genotypes of which of the following?
A. offspring that resemble the parents
B. offspring that exhibit a single crossover event
C. offspring that exhibit double crossover events
D. None of these choices are correct.
C. offspring that exhibit double crossover events
An organism that contains patches of tissue that vary for a specific characteristic, such as a pigment, is an example of _____.
A. linkage
B. meiotic recombination
C. translocations
D. mitotic recombination
D. mitotic recombination
Which of the following statistical tests is used to determine if two genes are linked or assorting independently?
A. chi square test
B. product rule
C. binomial expansion
D. sum rule
A. chi square test
A diploid organism has a total of 36 chromosomes. Assuming all possible chromosome combinations are viable, if a mutant tetraploid version of this organism was created how many chromosomes would it have? If a mutant version of the diploid organism was monosomic for chromosome 9 how many chromosomes would it have?
A. 144; 35
B. 72; 35
C. 72; 37
D. 144; 37
B. 72; 35
A _______ translocation occurs when a piece of one chromosome is attached to another chromosome.
A. balanced
B. complex
C. simple
D. reciprocal
C. simple
What process is the cause of human genetic diseases such a cri-du-chat syndrome?
A. deletion
B. translocation
C. inversion
D. duplication
A. deletion
Inversions detectable by light microscopy are contained within what percent of the human population?
A. less than 1%
B. greater than 10%
C. approximately 2%
D. approximately 5%
C. approximately 2%
A wholphin is a rare hybrid animal born from mating a female bottlenose dolphin with a male false killer whale. Wholphins are diploid. Interestingly, wholphins are fertile. What can you conclude from the fact that wholphins are fertile?
A. Wholphins are allotetraploid.
B. One of the parents must have been aneuploid.
C. Dolphins and false killer whales are actually the same species.
D. Dolphins and false killer whales likely have the same number of chromosomes.
D. Dolphins and false killer whales likely have the same number of chromosomes.
Which correctly describes mitotic nondisjunction?
A. It is a relatively rare event.
B. It results in the loss of chromosomes in some cells.
C. It usually does not affect all of the cells of the organism.
D. All of these choices are correct
D. All of these choices are correct
The failure of chromosomes to separate during anaphase is called __________.
A. nondisjunction
B. synapsis
C. epistasis
D. maternal effect
A. nondisjunction
Chromosomes may be identified based on which of the following characteristics?
A. location of the centromere
B. banding patterns
C. size of the chromosome
D. All of these choices are correct.
D. All of these choices are correct.
Edward and Patau syndromes are examples of __________.
A. allopolyploidy
B. autopolyploidy
C. translocations
D. aneuploidy
D. aneuploidy
The polytene chromosomes of Drosophila are an example of _________.
A. aneuploidy
B. polyploidy
C. translocations
D. inversion loops
E. None of these choices are correct.
B. polyploidy