Deck 24: Chromosomal Basis of Inheritance

Question 1

Color-blindness is inherited as an X-linked recessive trait. A male who is color-blind marries a heterozygous woman. What percent of their total children will be color-blind?

A) 0%
B) 25%
C) 50%
D) 75%
E) 100%

Answer 1

C

Question 2

Down syndrome

A) is due to disjunction of chromosomes.
B) individuals have two number 21 chromosomes.
C) may occur at a lower rate in women over 40.
D) can occur if the sperm has an extra copy of chromosome 21.
E) persons have normal-appearing eyelids.

Answer 2

D

Question 3

All of the genes on a single chromosome form a

A) locus.
B) homologous group.
C) a linkage map.
D) a linkage group.
E) information unit.

Answer 3

D

Question 4

During meiosis, what process can sometimes "unlink" genes?

A) synapsis
B) crossing over
C) independent assortment
D) metaphase II
E) the formation of tetrads

Question 5

Genes on which chromosome determine if the sex of a child will be male or female?

A) X
B) Y
C) 21st
D) 5th
E) 19th

Question 6

In Down syndrome, the Dart gene causes mental impairment by increasing the levels of pyrimidines in the blood.

Question 7

When homologous chromosomes fail to separate during meiosis, this is termed

A) linked genes.
B) disjunction.
C) nondisjunction.
D) crossover.
E) monosomy.

Question 8

In which way would males and females differ in terms of chromosomes?

A) the total number of autosomes
B) the loci for the majority of their genes
C) the types of sex chromosomes
D) the inheritance of one X chromosome from their mother
E) the need for two sex chromosomes

Question 9

Genes on the same chromosome are more likely to assort independently if

A) they are next to one another.
B) they are nearby one another.
C) they are located far apart.
D) they code for similar traits.
E) they code for traits that affect the same part of the body.

Question 10

If a person has short stature, a fold in the eyelids, fissured tongue, and mental impairment, they have

A) cri du chat syndrome.
B) Down syndrome.
C) fragile X syndrome.
D) Turner syndrome.
E) Klinefelter syndrome.

Question 11

Karyotyping can be used to diagnose which of the following genetic disorders?

A) Down syndrome
B) phenylketonuria
C) neurofibromatosis
D) cystic fibrosis
E) hemophilia

Question 12

Which of the following is a condition in which a person inherits an extra copy of a chromosome?

A) monosomy
B) disjunction
C) trisomy
D) inversion
E) duplication

Question 13

The most common autosomal abnormality seen among humans is

A) Edwards syndrome.
B) XXY.
C) Patau syndrome.
D) a deletion in chromosome 5.
E) trisomy 21.

Question 14

Which statement about Down syndrome is correct?

A) Down syndrome is caused by a third copy of chromosome 21.
B) Down syndrome is usually associated with chromosomal nondisjunction in meiosis.
C) Characteristics of Down syndrome include stubby fingers and a palm crease.
D) Individuals affected with Down syndrome display mental impairment.
E) All of the answer choices are correct about Down syndrome.

Question 15

Which refers to the loss of a complete chromosome?

A) inversion
B) translocation
C) deletion
D) duplication
E) monosomy

Question 16

The location of a gene on a chromosome is called

A) a locus.
B) a lacunae.
C) a link.
D) a gene marker.

Question 17

A normal male marries a color-blind woman. What percent of their female children will be color-blind?

A) 0%
B) 25%
C) 50%
D) 75%
E) 100%

Question 18

A female with two Barr bodies in her cells would have what combination of sex chromosomes?

A) XXY
B) XXXY
C) XXX
D) XX
E) XYY

Question 19

Genes that are linked do not show independent assortment.

Question 20

Which statement is true regarding a Barr body?

A) Barr bodies are found in the nuclei of female cells.
B) Barr bodies are found in the nuclei of male cells.
C) Barr bodies are found in the cytoplasm of male cells.
D) Barr bodies are found in the cytoplasm of female cells.
E) A Barr body is a condensed, inactive Y chromosome.

Question 21

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

Question 22

Which refers to the addition of a repeat segment of a chromosome?

A) inversion
B) translocation
C) deletion
D) duplication
E) monosomy

Question 23

The chances of survival are greater when trisomy or monosomy involves the sex chromosomes.

Question 24

Which of the following conditions is due to a sex-linked gene?

A) color-blindness
B) hemophilia
C) muscular dystrophy
D) inability to see red or green
E) All of the answer choices are sex-linked conditions.

Question 25

An individual who has an XXY combination of sex chromosomes is said to have

A) Klinefelter syndrome.
B) Turner syndrome.
C) Down syndrome.
D) Fragile X syndrome.
E) cri du chat syndrome.

Question 26

If an individual has a XYY genotype, they are classified as having

A) Down syndrome.
B) cri du chat syndrome.
C) Turner syndrome.
D) Klinefelter syndrome.
E) Jacobs syndrome.

Question 27

In fruit flies, bar eye is inherited by a dominant 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

Question 28

An XXX female would most likely result from nondisjunction in

A) the mother during egg formation.
B) the father during sperm formation.
C) in both the mother and father during gamete formation.
D) the fertilized egg.
E) neither the mother nor the father.

Question 29

Generally, it is not possible to determine whether nondisjunction failed to occur in oogenesis or spermatogenesis. However, it is possible to assert that XYY results from nondisjunction during

A) oogenesis.
B) spermatogenesis.
C) mitosis.
D) cytokinesis.

Question 30

Considering that males can have Klinefelter (XXY) syndrome, XYY, and normal XY chromosomal combinations, and females can have Turner (XO) syndrome, poly-X (XXX, XXXX), and normal XX combinations, it is obvious that

A) male characteristics result from the presence of only one X chromosome.
B) male characteristics result from the absence of two or more X chromosomes.
C) male characteristics result from the minimal presence of one Y chromosome.
D) female characteristics result from the presence of two or more X chromosomes.
E) sex determination is a delicate balance between X and Y chromosomes.

Question 31

If a chromosomal segment is turned around 180°, the chromosomal mutation is termed a(n)

A) translocation.
B) duplication.
C) deletion.
D) inversion.
E) monosomy.

Question 32

If a person has a portion of number 5 chromosome missing, they may have

A) Down syndrome.
B) cri du chat syndrome.
C) Turner syndrome.
D) Klinefelter syndrome.
E) Jacobs syndrome.

Question 33

Which of the following refers to the movement of a piece of one chromosome to another nonhomologous chromosome?

A) inversion
B) translocation
C) deletion
D) duplication
E) monosomy

Question 34

A person with an XO genotype is classified as having

A) Down syndrome.
B) cri du chat syndrome.
C) Turner syndrome.
D) Klinefelter syndrome.
E) a poly-X state.

Question 35

If a person inherits two X chromosomes, this individual will be

A) female.
B) male.
C) color-blind.
D) sterile.
E) a poly-X female.

Question 36

A female that has ovarian failure and does not undergo puberty may have

A) Klinefelter syndrome.
B) Down syndrome.
C) cri du chat syndrome.
D) Turner syndrome.
E) poly-X female state.

Question 37

If a woman is a carrier for the color-blind recessive allele and her husband has normal vision, what are their chances that a son will be color-blind?

A) none, because the father is normal
B) 50%, since the mother is only a carrier
C) 100%, because the mother has the gene
D) 25%, because the mother is a hybrid
E) None, since the son will also be just a carrier.

Question 38

The trait diagrammed in Figure 24.4 is inherited as a(n)

A) dominant X-linked trait.
B) recessive X-linked trait.
C) recessive Y-linked trait.
D) autosomal dominant trait.
E) dominant Y-linked trait.

Question 39

Which of the following refers to the loss of a portion of a chromosome?

A) inversion
B) translocation
C) deletion
D) duplication
E) monosomy

Question 40

Which of the following is true about a karyotype?

A) homologous chromosomes are arranged in pairs
B) sex chromosomes are identified separately from autosomes
C) chromosome pairs are assorted by both size and shape
D) banding patterns are used in pairing chromosomes
E) All of the answer choices are true about karyotypes.

Question 41

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.

Question 42

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) The phenotype 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 has blue eyes but will not determine whether a son will be a hemophiliac.
D) Regardless of the father, no sons will have blue eyes or be hemophiliacs.
E) Regardless of the father, the mother can only pass on blue eyes to her daughters and hemophilia to her sons.

Question 43

Which of the following sex-linked disorders was common among the royal families of Europe, and all of the affected males could trace their ancestry to Queen Victoria of England?

A) fragile X syndrome
B) hemophilia
C) color-blindness
D) Duchenne muscular dystrophy
E) None of the answer choices is true.

Question 44

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.

Question 45

List the possible zygote combinations that could occur if a man has one nondisjunction occur during meiosis II, but the woman's eggs are normal.

Question 46

Which of the following traits is part of the linkage group found on chromosome 19?

A) muscular dystrophy
B) hair color (brown)
C) colorectal cancer
D) eye color (green/blue)
E) All of the answer choices are part of a linkage group on chromosome 19.

Question 47

In the following question, the distance between alleles on a chromosome is visualized. Which of the following pairs of alleles would be most likely to cross over?

A) A..........B
B) A...B......
C) A......B.......C
D) AB.............
E) ).........AB

Question 48

Describe a genetic disorder associated with a deletion in a chromosome.

Question 49

Which one of the following x-linked disorders is caused by an abnormal number of repeat sequences in the genome and is the most common cause of inherited mental impairment?

A) fragile X syndrome
B) Klinefelter syndrome
C) Williams syndrome
D) cri du chat syndrome
E) Down syndrome

Question 50

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.

Question 51

A karyotype will detect which of the following genetic diseases?

A) Turner syndrome
B) Klinefelter syndrome
C) Down syndrome
D) cri du chat syndrome
E) All of the answer choices listed can be detected with a karyotype.

Question 52

List and describe the four X-linked recessive disorders.

Question 53

Which of the following sex-linked diseases is characterized by a waddling gait, toe walking, frequent falls, and difficulty in rising, and may appear as soon as the child starts to walk?

A) hemophilia
B) fragile X syndrome
C) color-blindness
D) Duchenne muscular dystrophy
E) None of the answer choices is true.