Question 1

In a human,what is the best explanation for being XX and phenotypically male?

Accepted Answer

A)  One of the X's is incomplete resembling a chromosome. 
B)  A small piece of the Y-chromosome, containing the SRY region, is inserted on the X-chromosome. 
C)  Both the X's have a mutation deleting the "female" forming genes. 
D)  There is a fragment of the Y-chromosome inserted on an autosomal chromosome. 
E)  The SRY gene has mutated. 
A)  One of the X's is incomplete resembling a chromosome. 
B)  A small piece of the Y-chromosome, containing the SRY region, is inserted on the X-chromosome. 
C)  Both the X's have a mutation deleting the "female" forming genes. 
D)  There is a fragment of the Y-chromosome inserted on an autosomal chromosome. 
E)  The SRY gene has mutated. B

Question 2

A (w+/ w+)red-eyed Drosophila female is crossed with a white-eyed male.Assuming the trait for eye color is sex-linked,what are the possible phenotypes of the progeny?

Accepted Answer

A)  All red eyed individuals 
B)  Red and white eyed females and males 
C)  Only red eyed females and white eyed males 
D)  Both red and white eyed males and only white eyed females 
E)  None of these 
A)  All red eyed individuals 
B)  Red and white eyed females and males 
C)  Only red eyed females and white eyed males 
D)  Both red and white eyed males and only white eyed females 
E)  None of these A

Question 3

Which individual is credited with linking the gene for eye color in Drosophila to the X chromosome?

Accepted Answer

A)  Thomas Hunt Morgan 
B)  Calvin Bridges 
C)  Gregor Mendel 
D)  Sutton and Boveri 
E)  None of these 
A)  Thomas Hunt Morgan 
B)  Calvin Bridges 
C)  Gregor Mendel 
D)  Sutton and Boveri 
E)  None of these A

Question 4

Which of Mendel's principles is a statement about the random alignment of different pairs of chromosomes at metaphase during meiosis?

Accepted Answer

A)  Dominance/Recessiveness 
B)  Segregation 
C)  Independent Assortment 
D)  All of these 
E)  None of these 
A)  Dominance/Recessiveness 
B)  Segregation 
C)  Independent Assortment 
D)  All of these 
E)  None of these

Question 5

Female mammals that contain two types of cell lineages in which the paternal X chromosome is inactivated in some cells and the maternal X chromosome is inactivated in others are known as:

Accepted Answer

A)  Genetic twins 
B)  Genetic mosaics 
C)  Genetic anomalies 
D)  None of these 
E)  All of these 
A)  Genetic twins 
B)  Genetic mosaics 
C)  Genetic anomalies 
D)  None of these 
E)  All of these

Question 6

Lightly stained regions of chromatin and darkly stained regions of chromatin are respectively known as:

Accepted Answer

A)  Heterochromatin and euchromatin 
B)  Euchromatin and heterochromatin 
C)  Haploid and diploid 
D)  Eukaryotic and prokaryotic 
E)  Chromosome and nucleus 
A)  Heterochromatin and euchromatin 
B)  Euchromatin and heterochromatin 
C)  Haploid and diploid 
D)  Eukaryotic and prokaryotic 
E)  Chromosome and nucleus

Question 7

Which of the following discovered chromosomes in the second half of the nineteenth century?

Accepted Answer

A)  Thomas Morgan 
B)  Calvin Bridges 
C)  W. Waldeyer 
D)  Gregor Mendel 
E)  Edmund Beecher Wilson 
A)  Thomas Morgan 
B)  Calvin Bridges 
C)  W. Waldeyer 
D)  Gregor Mendel 
E)  Edmund Beecher Wilson

Question 8

In mammals Dosage compensation for X-linked genes is achieved by:

Accepted Answer

A)  Hyperactivation of X-linked genes 
B)  Down regulation of X-linked genes 
C)  Inactivation of one X-chromosome during early development 
D)  All of these 
E)  None of these 
A)  Hyperactivation of X-linked genes 
B)  Down regulation of X-linked genes 
C)  Inactivation of one X-chromosome during early development 
D)  All of these 
E)  None of these

Question 9

Which of the following is required to unambiguously link a gene to a chromosome?

Accepted Answer

A)  The gene must be defined by a mutant allele 
B)  The chromosome must be morphologically distinguishable 
C)  The pattern of gene transmission must reflect the chromosome's behavior during reproduction. 
D)  All of these 
E)  None of these 
A)  The gene must be defined by a mutant allele 
B)  The chromosome must be morphologically distinguishable 
C)  The pattern of gene transmission must reflect the chromosome's behavior during reproduction. 
D)  All of these 
E)  None of these

Question 10

All chromosomes except X and Y are known as:

Accepted Answer

A)  Autosomes 
B)  Somosomes 
C)  Sex chromosomes 
D)  Somatosomes 
E)  Tetrasomes 
A)  Autosomes 
B)  Somosomes 
C)  Sex chromosomes 
D)  Somatosomes 
E)  Tetrasomes

Question 11

A man with hemophilia mates with a woman who is normal but whose father was a hemophiliac,mother was normal,and whose maternal grandmother was a hemophiliac.What percentage of their sons could be hemophiliacs?

Accepted Answer

50% of the

Question 12

A (w+/ w)red-eyed Drosophila female is crossed with a white-eyed male.Assuming the trait for eye color is sex-linked,what are the possible phenotypes of the progeny?

Accepted Answer

A)  All red eyed individuals 
B)  Red and white eyed females and males 
C)  Red eyed females and white eyed males 
D)  Both red and white eyed males and only white eyed females 
E)  None of these 
A)  All red eyed individuals 
B)  Red and white eyed females and males 
C)  Red eyed females and white eyed males 
D)  Both red and white eyed males and only white eyed females 
E)  None of these

Question 13

Which organism that was the first to be used to relate the behavior of chromosomes during meiosis to Mendel's principles of Segregation and Independent Assortment?

Accepted Answer

A)  Garden peas 
B)  Summer squash 
C)  Drosophila 
D)  Chickens 
E)  Sweetpeas 
A)  Garden peas 
B)  Summer squash 
C)  Drosophila 
D)  Chickens 
E)  Sweetpeas

Question 14

A white eyed Drosophila female is crossed with a red-eyed male.Assuming the trait for eye color is sex-linked,what are the possible phenotypes of the progeny?

Accepted Answer

A)  All red eyed individuals 
B)  Red and white eyed females and males 
C)  Red eyed females and white eyed males 
D)  Red and white eyed males and only white eyed females 
E)  None of these 
A)  All red eyed individuals 
B)  Red and white eyed females and males 
C)  Red eyed females and white eyed males 
D)  Red and white eyed males and only white eyed females 
E)  None of these

Question 15

The sex-linked disease called testicular feminization,if transferred from mother to son,forms:

Accepted Answer

A)  males (XY) that are phenotypically female and sterile. 
B)  females (XY) that are sterile. 
C)  males (XY) that are sterile. 
D)  females (XY) that are phenotypically male and are sterile. 
E)  fertile males (XY) 
A)  males (XY) that are phenotypically female and sterile. 
B)  females (XY) that are sterile. 
C)  males (XY) that are sterile. 
D)  females (XY) that are phenotypically male and are sterile. 
E)  fertile males (XY)

Question 16

In humans an individual who is genotyped as XO is a:

Accepted Answer

A)  Male 
B)  Female 
C)  Hermaphrodite 
D)  None of these 
E)  All of these 
A)  Male 
B)  Female 
C)  Hermaphrodite 
D)  None of these 
E)  All of these

Question 17

An organism that has only one copy of a gene is called a:

Accepted Answer

A)  Heterozygote 
B)  Homozygote 
C)  Hemizygote 
D)  Zygote 
E)  None of these 
A)  Heterozygote 
B)  Homozygote 
C)  Hemizygote 
D)  Zygote 
E)  None of these

Question 18

The view that all genes are located on chromosomes and that Mendel's principles can be explained by the transmissional properties of chromosomes during reproduction is known as:

Accepted Answer

A)  The Cell Theory 
B)  The Chromosome Theory of Heredity 
C)  The Sex-Linked Inheritance Theory 
D)  All of these 
E)  None of these 
A)  The Cell Theory 
B)  The Chromosome Theory of Heredity 
C)  The Sex-Linked Inheritance Theory 
D)  All of these 
E)  None of these

Question 19

The haploid number for a cell in a specific organism is 12.What is the number of chromosomes in a somatic cell in this organism?

Accepted Answer

A)  12 
B)  24 
C)  36 
D)  48 
E)  96 
A)  12 
B)  24 
C)  36 
D)  48 
E)  96

Question 20

A researcher crosses a white eyed female Drosophila with a red eyed male.Knowing that the gene for eye color is sex linked,he expects to observe only red-eyed females and white eyed males in the progeny.However,he observes that while most of the progeny are as expected,a small percentage of the males have red eyes.Explain what may have occurred to cause this result.

Accepted Answer

There may have been nondisjunction in ei

Exam 5: The Chromosomal Basis Of Mendelism

In a human,what is the best explanation for being XX and phenotypically male?

A (w+/ w+)red-eyed Drosophila female is crossed with a white-eyed male.Assuming the trait for eye color is sex-linked,what are the possible phenotypes of the progeny?

Which individual is credited with linking the gene for eye color in Drosophila to the X chromosome?

Which of Mendel's principles is a statement about the random alignment of different pairs of chromosomes at metaphase during meiosis?

Female mammals that contain two types of cell lineages in which the paternal X chromosome is inactivated in some cells and the maternal X chromosome is inactivated in others are known as:

Lightly stained regions of chromatin and darkly stained regions of chromatin are respectively known as:

Which of the following discovered chromosomes in the second half of the nineteenth century?

In mammals Dosage compensation for X-linked genes is achieved by:

Which of the following is required to unambiguously link a gene to a chromosome?

All chromosomes except X and Y are known as:

A man with hemophilia mates with a woman who is normal but whose father was a hemophiliac,mother was normal,and whose maternal grandmother was a hemophiliac.What percentage of their sons could be hemophiliacs?

A (w+/ w)red-eyed Drosophila female is crossed with a white-eyed male.Assuming the trait for eye color is sex-linked,what are the possible phenotypes of the progeny?

Which organism that was the first to be used to relate the behavior of chromosomes during meiosis to Mendel's principles of Segregation and Independent Assortment?

A white eyed Drosophila female is crossed with a red-eyed male.Assuming the trait for eye color is sex-linked,what are the possible phenotypes of the progeny?

The sex-linked disease called testicular feminization,if transferred from mother to son,forms:

In humans an individual who is genotyped as XO is a:

An organism that has only one copy of a gene is called a:

The view that all genes are located on chromosomes and that Mendel's principles can be explained by the transmissional properties of chromosomes during reproduction is known as:

The haploid number for a cell in a specific organism is 12.What is the number of chromosomes in a somatic cell in this organism?

The Science Of Genetics

Cellular Reproduction

Mendelism The Basic Principles Of Inheritance

Extensions Of Mendelism

Variation In Chromosome Number And Structure

Linkage,Crossing Over,And Chromosome Mapping In …

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

Population Genetics

Evolutionary Genetics

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