Question 1

Which one of the following disorders listed below is NOT caused by a change in chromosome structure?
A)fragile X syndrome
B)Klinefelter syndrome
C)Williams syndrome
D)cri du chat syndrome
E)All of the answer choices are caused by a change in chromosome structure.

Accepted Answer

Klinefelter syndrome is caused by an extra X chromosome (XXY) and is a change in chromosome number, not structure.

Question 2

Which trait is not part of the linkage group found on chromosome 19?
A)production of elastin
B)muscular dystrophy
C)hair color (brown)
D)eye color (green/blue)
E)colorectal cancer

Accepted Answer

The answer of Which trait is not part of the...

Question 3

In fruit flies,bar eye is inherited by an X-linked allele (B for bar).If a heterozygous bar-eyed female is mated to a non-bar-eyed male,what will be the expected ratio of phenotype given four offspring?
A)two bar-eyed females,two bar-eyed males
B)one bar-eyed and one non-bar-eyed female,one bar-eyed and one non-bar-eyed male
C)three bar-eyed females and one non-bar-eyed male
D)bar-eyed females only
E)non-bar-eyed males only

Accepted Answer

The heterozygous female has one X chromosome with the bar allele and one X chromosome with the non-bar allele. The non-bar-eyed male has two non-bar alleles. Therefore, the possible genotypes of the offspring are BB, B, and non-bar. The expected ratio of phenotypes in four offspring would be one of each of the possible genotypes, resulting in one bar-eyed and one non-bar-eyed female, one bar-eyed and one non-bar-eyed male.

Question 4

A mother is a carrier for blue eyes (autosomal recessive)and for hemophilia (X-linked recessive).Which of these is a correct statement?
A)All sons will have blue eyes and be hemophiliacs.
B)It depends on the father's genotype as to whether the sons will have blue eyes and/or be hemophiliacs.
C)The father's genotype can determine whether a son will have blue eyes but cannot determine whether a son will be a hemophiliac.
D)Regardless of the father,no sons will have blue eyes or be hemophiliacs.
E)There is a linkage between eye color and hemophilia.

Accepted Answer

The answer of A mother is a carrier for blue...

Question 5

A karyotype will NOT reveal which of the following genetic diseases?
A)Turner syndrome
B)Klinefelter syndrome
C)Down syndrome
D)cri du chat syndrome
E)hemophilia

Accepted Answer

A karyotype is a visual representation of an individual's chromosomes to identify any abnormality in chromosome number or structure. Hemophilia is a genetic disorder caused by a mutation in a specific gene on the X chromosome, which cannot be detected by a karyotype because it only assesses the number and appearance of chromosomes, not specific genes. Turner syndrome, Klinefelter syndrome, Down syndrome, and cri du chat syndrome are all chromosomal disorders that can be detected by a karyotype.

Question 6

A color-blind (recessive trait)woman will pass the allele to
A)her sons only.
B)all her children.
C)her daughters only.
D)none of her children.
E)her husband.

Accepted Answer

A color-blind woman must have at least one recessive allele for color-blindness. If she mates with a man with normal color vision, there is a 50% chance that any child they have will receive the recessive allele from the mother, making them a carrier of color-blindness but not affected themselves. Therefore, all her children have the potential to inherit the allele, regardless of gender.

Question 7

Which genetic disorder is the result of a deletion of a section of an individual's chromosome?
A)Williams syndrome
B)Klinefelter syndrome
C)Down syndrome
D)Turner syndrome
E)None of the answer choices is the result of a deletion of a section of an individual's chromosome.

Accepted Answer

Williams syndrome is caused by the deletion of genetic material from a specific region of chromosome 7. This deletion includes more than 25 genes, and the loss of these genes leads to the developmental and physical symptoms of the disorder.

Question 8

Which of the following is NOT true about a karyotype?
A)Homologous chromosomes are arranged in pairs.
B)Sex chromosomes are identified separately from autosomes.
C)All chromosome pairs are numbered differently for males and females.
D)Chromosome pairs are assorted by both size and shape.
E)Banding patterns are used in pairing chromosomes.

Accepted Answer

Chromosome pairs are numbered the same way in both males and females. For example, chromosome pair number 1 is the longest pair of chromosomes and is labeled as such in both males and females.

Question 9

Hemophilia (h)is a sex-linked recessive trait.If a hemophiliac male marries a carrier female,
A)50% of their daughters will be hemophiliac.
B)75% of their daughters will be hemophiliac.
C)25% of their daughters will be hemophiliac.
D)25% of their sons will be hemophiliac.
E)75% of their sons will be hemophiliac.

Accepted Answer

The answer of Hemophilia (h)is a sex-linked recessive trait.If a...

Question 10

Which disorder is characterized by a lack of the protein dystrophin?
A)hemophilia
B)color-blindness
C)muscular dystrophy
D)Down syndrome
E)cystic fibrosis

Accepted Answer

Muscular dystrophy is a genetic disorder that is characterized by a lack of the protein dystrophin, which plays a crucial role in maintaining the structural integrity of muscles. The absence of dystrophin results in progressive muscle weakness and wasting. Hemophilia is a genetic disorder that impairs the body's ability to control bleeding, while color-blindness results from a deficiency in color-detecting cells in the eyes. Down syndrome is a genetic disorder that results from the presence of an extra copy of chromosome 21, and cystic fibrosis is a genetic disorder that affects the respiratory, digestive, and reproductive systems.

Question 11

Describe a genetic disorder associated with a deletion in chromosomal number.

Accepted Answer

The answer of Describe a genetic disorder associated with a...

Question 12

Which of the following sex-linked disorders is characterized by an abnormal number of repeat sequences in the genome?
A)fragile X syndrome
B)hemophilia
C)color-blindness
D)Duchenne muscular dystrophy
E)None of the answer choices is true.

Accepted Answer

Fragile X syndrome is caused by an expansion of CGG repeats in the FMR1 gene on the X chromosome, leading to a loss of function of the FMR1 protein. Hemophilia is caused by mutations in genes that code for clotting factors, while color-blindness is caused by mutations in genes involved in color perception. Duchenne muscular dystrophy is caused by mutations in the dystrophin gene on the X chromosome. None of the answer choices is not true, as one choice (A) is true.

Question 13

Which of the following sex-linked diseases is characterized by the absence of a clotting factor?
A)hemophilia
B)fragile X syndrome
C)color-blindness
D)Duchenne muscular dystrophy
E)None of the answer choices is true.

Accepted Answer

Hemophilia is a sex-linked recessive disorder that is characterized by the absence or deficiency of a clotting factor, most commonly Factor VIII or Factor IX. This results in prolonged bleeding and difficulty in clotting after injury or surgery. Fragile X syndrome, color-blindness, and Duchenne muscular dystrophy are also sex-linked disorders but do not involve clotting factors.

Quiz 24: Chromosomal Inheritance and Genetic Disorders

Which one of the following disorders listed below is NOT caused by a change in chromosome structure?

Which trait is not part of the linkage group found on chromosome 19?

In fruit flies,bar eye is inherited by an X-linked allele (B for bar) .If a heterozygous bar-eyed female is mated to a non-bar-eyed male,what will be the expected ratio of phenotype given four offspring?

A mother is a carrier for blue eyes (autosomal recessive) and for hemophilia (X-linked recessive) .Which of these is a correct statement?

A karyotype will NOT reveal which of the following genetic diseases?

A color-blind (recessive trait) woman will pass the allele to

Which genetic disorder is the result of a deletion of a section of an individual's chromosome?

Which of the following is NOT true about a karyotype?

Hemophilia (h) is a sex-linked recessive trait.If a hemophiliac male marries a carrier female,

Which disorder is characterized by a lack of the protein dystrophin?

Describe a genetic disorder associated with a deletion in chromosomal number.

Which of the following sex-linked disorders is characterized by an abnormal number of repeat sequences in the genome?

Which of the following sex-linked diseases is characterized by the absence of a clotting factor?