Question 1

Typically,each crossover event produces how many recombinants?

Accepted Answer

A)  1 
B)  2 
C)  3 
D)  4 
E)  5 
A)  1 
B)  2 
C)  3 
D)  4 
E)  5 B

Question 2

The phenomenon in which genes on the same chromosome are separated from each other during meiosis and new combinations of genes are formed is known as:

Accepted Answer

A)  Linkage 
B)  Synapsis 
C)  Recombination 
D)  Nondisjunction 
E)  Disjunction 
A)  Linkage 
B)  Synapsis 
C)  Recombination 
D)  Nondisjunction 
E)  Disjunction C

Question 3

In this type of ascus there are four kinds of ascospores,one that is like each of the parents and two that are recombinant.

Accepted Answer

A)  Parental ditype ascus 
B)  Nonparental ditype ascus 
C)  Tetratype 
D)  Quadratype 
E)  Recombinant type ascus 
A)  Parental ditype ascus 
B)  Nonparental ditype ascus 
C)  Tetratype 
D)  Quadratype 
E)  Recombinant type ascus C

Question 4

The distance between two points on the genetic map of a chromosome is equal to:

Accepted Answer

A)  The average number of crossovers between them 
B)  The exact number of crossovers between them as measured in one cell 
C)  The estimated number of crossovers between them as measured in one cell 
D)  None of these 
E)  All of these 
A)  The average number of crossovers between them 
B)  The exact number of crossovers between them as measured in one cell 
C)  The estimated number of crossovers between them as measured in one cell 
D)  None of these 
E)  All of these

Question 5

Which of the following statement is false regarding linked genes?

Accepted Answer

A)  The more closely the genes are linked the less often they recombine 
B)  The recombination frequency for any set of genes often exceeds 50% 
C)  Recombination occurs most frequently between genes that are not closely linked 
D)  All of these are true statements regarding linked genes 
E)  All of these are false statements regarding linked genes 
A)  The more closely the genes are linked the less often they recombine 
B)  The recombination frequency for any set of genes often exceeds 50% 
C)  Recombination occurs most frequently between genes that are not closely linked 
D)  All of these are true statements regarding linked genes 
E)  All of these are false statements regarding linked genes

Question 6

111
-Wild-type Drosophila females were mated to males homozygous for two autosomal mutations-vestigial (vg),which produces short wings,and black (b),which produces a black body.All the F? flies had long wings and gray bodies; thus,the wild-type alleles (vg? and b?)are dominant.The F? females were then testcrossed to vestigial,black males,and the F? progeny were sorted by phenotype and counted.Simple analysis indicates that,on average,18 out of 100 chromosomes recovered from meiosis had a crossover between vg and b.Thus,vg and b are how far apart?
A) 82 centimorgans
B) 82 morgans
C) 18 centimorgans
D) 18 morgans
E) 100 centimorgans

Accepted Answer

The answer of 111
-Wild-type Drosophila females were mated to males...

Question 7

Which of the following is a true statement regarding the frequency of crossing over in chromosomes? 1.Crossing over is less likely to occur near the ends of a chromosome
2)Crossing over is less likely to occur near the centromere
3)Crossing over is more likely to occur near the ends of the chromosome

Accepted Answer

A)  1 
B)  2 
C)  3 
D)  1 and 2 
E)  2 and 3 
A)  1 
B)  2 
C)  3 
D)  1 and 2 
E)  2 and 3

Question 8

The basic principle in deletion mapping is that:

Accepted Answer

A)  A deletion that uncovers a recessive mutation must lack a wild-type copy of the mutant gene 
B)  A deletion that covers a recessive mutation must lack a wild-type copy of the mutant gene 
C)  A deletion that uncovers a recessive mutation must contain a wild type copy of the mutant gene 
D)  A deletion that covers a recessive mutation must contain the recessive mutation of the gene 
E)  All of these 
A)  A deletion that uncovers a recessive mutation must lack a wild-type copy of the mutant gene 
B)  A deletion that covers a recessive mutation must lack a wild-type copy of the mutant gene 
C)  A deletion that uncovers a recessive mutation must contain a wild type copy of the mutant gene 
D)  A deletion that covers a recessive mutation must contain the recessive mutation of the gene 
E)  All of these

Question 9

Which of the following is a true statement about the linkage phase diagram R l / r L 1.The slash (/)separates alleles inherited from different parents
2)The alleles on the left and right of the slash indicate genotype on different homologous chromosomes
3)The genotype has the repulsion linkage phase

Accepted Answer

A)  1 
B)  2 
C)  3 
D)  1 and 2 
E)  All of these 
A)  1 
B)  2 
C)  3 
D)  1 and 2 
E)  All of these

Question 10

In maize,three recessive genes (z,xt,and cm)are linked on chromosome 3.A homozygous plant for the recessives is crossed with a wild-type plant.The F? is crossed to get an F? generation with the following results:

Accepted Answer

11 map uni

Question 11

A coefficient of coincidence that is equal to 1 implies:

Accepted Answer

A)  That the crossover events are independent 
B)  That the crossover events are not independent 
C)  That one crossover event interferes with another crossover event 
D)  That one crossover event catalyzes another crossover event 
E)  None of these 
A)  That the crossover events are independent 
B)  That the crossover events are not independent 
C)  That one crossover event interferes with another crossover event 
D)  That one crossover event catalyzes another crossover event 
E)  None of these

Question 12

True genetic distance may be much greater than the observed recombination frequency.Which is not an explanation of this phenomenon?

Accepted Answer

A)  The genes are far apart. 
B)  Two crossover events may not produce recombinant chromosomes. 
C)  Four crossover events may not produce recombinant chromosomes. 
D)  Interference with 2 genes that are tightly linked affects the recombination frequency. 
E)  A double crossover contributes to the average number of exchanges on a chromosome. 
A)  The genes are far apart. 
B)  Two crossover events may not produce recombinant chromosomes. 
C)  Four crossover events may not produce recombinant chromosomes. 
D)  Interference with 2 genes that are tightly linked affects the recombination frequency. 
E)  A double crossover contributes to the average number of exchanges on a chromosome.

Question 13

In one type of ascus neither of the two genotypes is like the parental genotypes; thus,the ascus is called a:

Accepted Answer

A)  Parental ditype ascus 
B)  Nonparental ditype ascus 
C)  Original phenotype ascus 
D)  Recombinant phenotype ascus 
E)  None of these 
A)  Parental ditype ascus 
B)  Nonparental ditype ascus 
C)  Original phenotype ascus 
D)  Recombinant phenotype ascus 
E)  None of these

Question 14

Why doesn't an exchange between sister chromatids result in the production of a recombinant?

Accepted Answer

A)  Sister chromatids are genetically identical and therefore an exchange would not show any change in phenotype 
B)  Sister chromatids are not genetically identical and therefore cannot exchange information 
C)  Sister chromatids are genetically identical and therefore cannot exchange information 
D)  Sister chromatids are not genetically identical and therefore an exchange would not show any change in phenotype 
E)  None of these explains this 
A)  Sister chromatids are genetically identical and therefore an exchange would not show any change in phenotype 
B)  Sister chromatids are not genetically identical and therefore cannot exchange information 
C)  Sister chromatids are genetically identical and therefore cannot exchange information 
D)  Sister chromatids are not genetically identical and therefore an exchange would not show any change in phenotype 
E)  None of these explains this

Question 15

45)An individual with two a⁺b⁺c⁺d⁺e⁺ .chromosomes is crossed with an individual with two a⁻d⁻c⁻b⁻e⁻ chromosomes.What will happen in the F₁ during meiosis?

Accepted Answer

A)  Acentric fragments cannot be formed. 
B)  Acentric fragments cannot be formed.. 
C)  The F1 will form many viable gametes. 
D)  Recombination will be suppressed between the sister chromatids. 
E)  All of these 
A)  Acentric fragments cannot be formed. 
B)  Acentric fragments cannot be formed.. 
C)  The F1 will form many viable gametes. 
D)  Recombination will be suppressed between the sister chromatids. 
E)  All of these

Question 16

In a data set to determine crossover frequency between the sc,ec,and cv genes in Drosophila,the crossover frequency between ec and sc = 0.15,and ec and cv = .25.The number of double crossover flies was 15 out of 500 flies.Assuming sc,ec,cv is the respective order of the genes,what can we conclude from this result?

Accepted Answer

A)  The coefficient of coincidence is near zero. 
B)  The expected number of crossovers and the observed numbers are different. 
C)  The genes are tightly linked. 
D)  The coefficient of coincidence is near one. 
E)  There is a large amount of interference between these genes. 
A)  The coefficient of coincidence is near zero. 
B)  The expected number of crossovers and the observed numbers are different. 
C)  The genes are tightly linked. 
D)  The coefficient of coincidence is near one. 
E)  There is a large amount of interference between these genes.

Question 17

Which of the following is true regarding recombination and evolution? 1.Recombination can bring favorable mutations together
2)Chromosome rearrangements can suppress recombination
3)Recombination is under genetic control

Accepted Answer

A)  1 
B)  2 
C)  3 
D)  1 and 2 
E)  All of these 
A)  1 
B)  2 
C)  3 
D)  1 and 2 
E)  All of these

Question 18

In one type of ascus,two of the ascospores are genotypically like one of the parents and two are like the other parent.An ascus with this pattern is called a:

Accepted Answer

A)  Parental ditype ascus 
B)  Nonparental ditype ascus 
C)  Original phenotype ascus 
D)  Recombinant phenotype ascus 
E)  None of these 
A)  Parental ditype ascus 
B)  Nonparental ditype ascus 
C)  Original phenotype ascus 
D)  Recombinant phenotype ascus 
E)  None of these

Question 19

Which of the following most accurately represents how Alfred H Sturtevant created the first chromosome map?

Accepted Answer

A)  He used a microscope to view the genes 
B)  He used a set of microcalipers to measure the distance between the genes on the chromosome 
C)  He used the data he retrieved from his experimental crosses to determine the distance between the genes on the chromosome 
D)  All of these 
E)  None of these 
A)  He used a microscope to view the genes 
B)  He used a set of microcalipers to measure the distance between the genes on the chromosome 
C)  He used the data he retrieved from his experimental crosses to determine the distance between the genes on the chromosome 
D)  All of these 
E)  None of these

Question 20

Two yeast strains are crossed and,it is observed that there is a very low frequency of nonparental ditype asci.What can you conclude about the genes being studied? 1.The genes are most likely not linked
2)The genes are most likely linked
3)The genes are most likely far apart from each other

Accepted Answer

A)  1 
B)  2 
C)  3 
D)  2 and 3 
E)  All of these 
A)  1 
B)  2 
C)  3 
D)  2 and 3 
E)  All of these

Exam 7: Linkage,Crossing Over,And Chromosome Mapping In …

Typically,each crossover event produces how many recombinants?

The phenomenon in which genes on the same chromosome are separated from each other during meiosis and new combinations of genes are formed is known as:

In this type of ascus there are four kinds of ascospores,one that is like each of the parents and two that are recombinant.

The distance between two points on the genetic map of a chromosome is equal to:

Which of the following statement is false regarding linked genes?

The basic principle in deletion mapping is that:

In maize,three recessive genes (z,xt,and cm)are linked on chromosome 3.A homozygous plant for the recessives is crossed with a wild-type plant.The F? is crossed to get an F? generation with the following results:

A coefficient of coincidence that is equal to 1 implies:

True genetic distance may be much greater than the observed recombination frequency.Which is not an explanation of this phenomenon?

In one type of ascus neither of the two genotypes is like the parental genotypes; thus,the ascus is called a:

Why doesn't an exchange between sister chromatids result in the production of a recombinant?

45)An individual with two a⁺b⁺c⁺d⁺e⁺ .chromosomes is crossed with an individual with two a⁻d⁻c⁻b⁻e⁻ chromosomes.What will happen in the F₁ during meiosis?

Which of the following is true regarding recombination and evolution? 1.Recombination can bring favorable mutations together 2)Chromosome rearrangements can suppress recombination 3)Recombination is under genetic control

In one type of ascus,two of the ascospores are genotypically like one of the parents and two are like the other parent.An ascus with this pattern is called a:

Which of the following most accurately represents how Alfred H Sturtevant created the first chromosome map?

Two yeast strains are crossed and,it is observed that there is a very low frequency of nonparental ditype asci.What can you conclude about the genes being studied? 1.The genes are most likely not linked 2)The genes are most likely linked 3)The genes are most likely far apart from each other

The Science Of Genetics

Cellular Reproduction

Mendelism The Basic Principles Of Inheritance

Extensions Of Mendelism

The Chromosomal Basis Of Mendelism

Variation In Chromosome Number And Structure

The Genetics Of Bacteria And Their Viruses

DNA And The Molecular Structure Of Chromosomes

Replication Of DNA And Chromosomes

Transcription And RNA Processing

Translation And The Genetic Code

Mutation,DNA Repair,And Recombination

The Techniques Of Molecular Genetics

Genomics

Applications Of Molecular Genetics

Transposable Genetics Elements

Regulation Of Gene Expression In Prokaryotes

Regulation Of Gene Expression In Eukaryotes

The Genetic Control Of Animal Development

The Genetic Basis Of Cancer

Inheritance Of Complex Traits

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