Chapter 12 Units of Heredity: Chromosomes and Inheritance
Updated: Aug 20, 2022
Biology: A Guide to the Natural World, 5e (Krogh)
1) A woman who is a carrier for the hemophilia gene has a child with a man who does not have hemophilia. Which prediction is correct?
A) All of the sons and none of the daughters will have hemophilia.
B) All of the daughters and none of the sons will have hemophilia.
C) Half of the sons and half of the daughters will have hemophilia.
D) Half of the sons and none of the daughters will have hemophilia.
E) Half of the daughters and none of the sons will have hemophilia.
Answer: D
Topic: Section 12.1
Skill: Application/Analysis
2) A woman who does not carry the color-blindness allele has children with a man who is color blind. What proportion of their children will be color blind?
A) all
B) 1/4
C) 1/2
D) 3/4
E) none
Answer: E
Topic: Section 12.1
Skill: Application/Analysis
3) Regarding the human sex chromosomes, which statement is correct?
A) The Y chromosome carries a greater number of genes than does the X chromosome.
B) X and Y are different in size but carry nearly equal numbers of genes.
C) The X chromosome carries more genes than does the Y chromosome.
D) The X chromosome carries only gender-related genes.
E) The X chromosome carries the genes for the development of male phenotype.
Answer: C
Topic: Section 12.1
Skill: Knowledge/Comprehension
4) What percent of males have some degree of color blindness?
A) 0.5 percent
B) 5 percent
C) 0.8 percent
D) 8 percent
E) 10 percent
Answer: D
Topic: Section 12.1
Skill: Knowledge/Comprehension
5) A trait such as albinism is seen with equal frequency in males and females. Two people who do not have the trait might have offspring who do have the trait, at a frequency of approximately one in four. What can you conclude about the inheritance of this trait?
A) recessive, X-linked
B) recessive, autosomal
C) recessive, caused by polyploidy
D) dominant, X-linked
E) dominant, autosomal
Answer: B
Topic: Section 12.1
Skill: Application/Analysis
6) What is a recessive disorder?
A) a genetic disorder with two functioning alleles
B) a genetic disorder that will express itself in the presence of one functioning allele
C) a genetic disorder that will express itself in the presence of two recessive alleles
D) a genetic disorder that involves change in chromosome number
E) a genetic disorder that involves change in chromosome structure
Answer: C
Topic: Section 12.1
Skill: Knowledge/Comprehension
7) Why do X-linked conditions appear more frequently in males than in females?
A) A male with a nonfunctioning allele on the X chromosome does not have another allele of that gene on the Y chromosome that could cover up the nonfunctioning one.
B) Males have no X chromosomes.
C) The Y chromosome carries many alleles that are recessive to alleles on the X chromosome.
D) Males are more likely to inherit an extra chromosome than females.
E) Females have no X chromosomes.
Answer: A
Topic: Section 12.1
Skill: Knowledge/Comprehension
8) What do hemophilia, Duchenne muscular dystrophy, and red-green color blindness have in common?
A) They are X-linked.
B) They are more common in females than in males.
C) They are caused by inheritance of an extra sex chromosome.
D) They are caused by inheritance of an extra autosome.
E) The gene that causes them is on the Y chromosome.
Answer: A
Topic: Section 12.1
Skill: Knowledge/Comprehension
9) If a daughter expresses an X-linked recessive gene, she probably inherited the trait from:
A) her mother.
B) her father.
C) both parents.
D) neither parent.
E) her grandmother.
Answer: C
Topic: Section 12.1
Skill: Knowledge/Comprehension
10) Red-green color blindness is an X-linked recessive trait in humans. A color-blind woman and a man with normal vision have a son. What is the probability that the son is color blind?
A) 100 percent
B) 75 percent
C) 50 percent
D) 25 percent
E) 0 percent
Answer: A
Topic: Section 12.1
Skill: Application/Analysis
11) Color blindness is caused by an X-linked recessive gene. A color-blind man and a woman with normal vision whose father was color blind have a son. The probability that their son is color blind is:
A) 0.25 (or 25 percent).
B) 0.50 (or 50 percent).
C) 0.75 (or 75 percent).
D) 1.00 (or 100 percent).
E) none of these.
Answer: B
Topic: Section 12.1
Skill: Application/Analysis
12) Who is a "carrier" of X-linked disorders, such as hemophilia and color blindness?
A) a person who has the X-linked disorder
B) a heterozygous female who is normal but carries one nonfunctioning allele
C) a homozygous female who carries the normal alleles
D) a male who carries the nonfunctioning allele
E) a male who carries the functioning allele
Answer: B
Topic: Section 12.2
Skill: Knowledge/Comprehension
13) An autosomal recessive disorder:
A) requires that only one parent be a carrier.
B) displays its symptoms only in heterozygotes.
C) is more frequent in males than females.
D) will appear only in children of parents who both carry the gene.
E) is dominant in females.
Answer: D
Topic: Section 12.2
Skill: Knowledge/Comprehension
14) Genes not found on the sex chromosomes will be found on:
A) X chromosomes.
B) Y chromosomes.
C) autosomes.
D) centrosomes.
Answer: C
Topic: Section 12.2
Skill: Knowledge/Comprehension
15) If a disease is caused by a dominant allele, it means that a person with the disease:
A) will always pass it on to all their children.
B) will pass it on to one-fourth of their children.
C) must be homozygous dominant for the allele.
D) must be heterozygous for the allele.
E) could be either homozygous or heterozygous for the allele.
Answer: E
Topic: Section 12.2
Skill: Knowledge/Comprehension
16) A person who is heterozygous for the Huntington disease (HD) allele has offspring with someone who does not have HD. What proportion of their children will have HD?
A) 1/16
B) 1/10
C) 1/8
D) 1/4
E) 1/2
Answer: E
Topic: Section 12.2
Skill: Application/Analysis
17) A person with an inherited disorder has children with a person who does not have the condition. Half the children have the disorder, both sons and daughters. How is this condition inherited?
A) autosomal dominant
B) autosomal recessive
C) X-linked dominant
D) X-linked recessive
E) aneuploidy
Answer: A
Topic: Section 12.2
Skill: Application/Analysis
18) What condition is caused by a dominant allele of a single gene?
A) Down syndrome
B) sickle-cell anemia
C) Huntington disease
D) color blindness
E) Turner syndrome
Answer: C
Topic: Section 12.2
Skill: Knowledge/Comprehension
19) A person who has a recessive disorder but does not have the disorder him or herself is said to be a/an:
A) aneuploid.
B) aberration.
C) carrier.
D) hybrid.
Answer: C
Topic: Section 12.2
Skill: Knowledge/Comprehension
20) What is the connection between sickle-cell anemia and malaria?
A) Both are X-linked.
B) Both are autosomal recessive.
C) Both are dominant.
D) Heterozygotes for malaria have some resistance to sickle-cell anemia.
E) Heterozygotes for sickle-cell anemia have some resistance to malaria.
Answer: E
Topic: Section 12.2
Skill: Knowledge/Comprehension
21) Which of the following is an autosomal recessive disorder?
A) hemophilia
B) Huntington disease
C) Down syndrome
D) sickle-cell anemia
E) Turner syndrome
Answer: D
Topic: Section 12.2
Skill: Knowledge/Comprehension
22) Which of the following genetic disorders is caused by a dominant allele but does not produce symptoms until the affected individual is well into adulthood?
A) Turner syndrome
B) Down syndrome
C) Huntington disease
D) sickle-cell anemia
E) hemophilia
Answer: C
Topic: Section 12.2
Skill: Knowledge/Comprehension
23) In a pedigree chart, a darkened square demonstrates a:
A) diseased male.
B) diseased female.
C) normal male.
D) normal female.
Answer: A
Topic: Section 12.3
Skill: Knowledge/Comprehension
24) A study of several pedigrees demonstrates that two parents are normal. If some of their children express a trait, then the trait is controlled by a:
A) codominant gene.
B) simple dominant gene.
C) recessive gene.
D) sex-linked gene.
Answer: C
Topic: Section 12.3
Skill: Application/Analysis
25) A pedigree is a representation of:
A) a genetic family tree.
B) a series of chromosomes arranged in order.
C) the inheritance pattern of recessive disorders.
D) the inheritance pattern of dominant disorders.
E) all the genetic disorders that can be inherited.
Answer: A
Topic: Section 12.3
Skill: Knowledge/Comprehension
26) You are tracking the inheritance of a genetic disorder through a family's pedigree, and you notice that it shows up in every generation. The disorder is most likely:
A) recessive.
B) dominant.
C) X-linked recessive.
Answer: B
Topic: Section 12.3
Skill: Application/Analysis
27) If more than one sperm fertilizes an egg, which of the following can result?
A) an autosomal dominant disorder
B) an autosomal recessive disorder
C) aneuploidy
D) polyploidy
Answer: D
Topic: Section 12.4
Skill: Knowledge/Comprehension
28) The human genome has how many pairs of autosomal chromosomes?
A) 46 pairs
B) 44 pairs
C) 23 pairs
D) 22 pairs
E) 24 pairs
Answer: D
Topic: Section 12.4
Skill: Knowledge/Comprehension
29) The state of having more than two sets of chromosomes is called:
A) autosomal.
B) dominant.
C) polyploidy.
D) aneuploidy.
E) nondisjunction.
Answer: C
Topic: Section 12.4
Skill: Knowledge/Comprehension
30) What is one difference between polyploidy and aneuploidy?
A) Polyploidy is extra sets of chromosomes; aneuploidy occurs when there are either more or fewer chromosomes than normally exist in its species full set.
B) Humans can be viable as polyploids but not as aneuploids.
C) Polyploidy is extra sex chromosomes; aneuploidy is extra autosomes.
D) Polyploidy is one extra chromosome; aneuploidy is one missing chromosome.
E) Polyploidy causes diseases and disorders in humans; aneuploidy does not.
Answer: A
Topic: Section 12.5
Skill: Knowledge/Comprehension
31) What is nondisjunction?
A) failure of sperm and egg to fuse in fertilization
B) failure of cells to divide by cytokinesis in meiosis
C) failure of chromosomes to duplicate before mitosis or meiosis
D) failure of homologous chromosomes or sister chromatids to separate in meiosis
E) an extra duplication of the chromosomes before mitosis or meiosis
Answer: D
Topic: Section 12.5
Skill: Knowledge/Comprehension
32) In humans, aneuploidy is fairly common yet goes largely unrecognized as a genetic problem. This is because:
A) it produces autosomal recessive individuals who don't always express the disorder.
B) its effects are usually hidden.
C) it actually produces healthy individuals.
D) it often results in miscarriage of embryos.
Answer: D
Topic: Section 12.5
Skill: Knowledge/Comprehension
33) Down syndrome in humans is caused by:
A) an extra X chromosome.
B) an extra y chromosome.
C) three copies of chromosome 21.
D) three copies of chromosome 13.
E) a single copy of chromosome 21.
Answer: C
Topic: Section 12.5
Skill: Knowledge/Comprehension
34) Aneuploid human embryos are least likely to survive except those involving:
A) chromosome 1, 2, 3, X, Y.
B) chromosome 1, 2, 3, 4, 5.
C) chromosome 13, 18, 21, X, Y.
D) chromosome 6, 7, 8, 9, 10.
E) chromosome 11, 12, 14, 15.
Answer: C
Topic: Section 12.5
Skill: Knowledge/Comprehension
35) If a diploid cell from an organism has 46 chromosomes, how many chromosomes are likely to be found in a gamete that is the result of nondisjunction?
A) 46 or 92
B) 23 or 22
C) 21 or 22
D) 22 or 24
E) 24 or 25
Answer: D
Topic: Section 12.5
Skill: Application/Analysis
36) A woman is missing one of her X chromosomes. With which of the following conditions would she be diagnosed?
A) Turner syndrome
B) polyploidy
C) a chromosomal deletion
D) Klinefelter syndrome
E) cancer
Answer: A
Topic: Section 12.5
Skill: Knowledge/Comprehension
37) A person with the genotype XO is mainly female, phenotypically. A person with the genotype XXY is mainly male. What can you conclude about the Y chromosome?
A) It has the same genes as X, just different alleles.
B) It has the same genes as X, in different orientation.
C) A Y chromosome confers maleness, regardless of the number of X chromosomes.
D) The only genes it carries are for female development.
E) A human cannot survive without a Y chromosome.
Answer: C
Topic: Section 12.5
Skill: Application/Analysis
38) If a zygote has the genotype XYY, how many total chromosomes were in the sperm before it fused with the egg?
A) 20
B) 21
C) 22
D) 23
E) 24
Answer: E
Topic: Section 12.5
Skill: Application/Analysis
39) Nondisjunction of the X chromosomes may occur during formation of gametes and produce two kinds of eggs. If normal sperm fertilizes these two kinds of eggs, which of the following pairs of genotypes are possible?
A) XX and XY
B) XXY and XO
C) XYY and XO
D) XYY and YO
Answer: B
Topic: Section 12.5
Skill: Application/Analysis
40) Which condition or disease is caused by aneuploidy?
A) sickle-cell anemia
B) hemophilia
C) malaria
D) color blindness
E) Down syndrome
Answer: E
Topic: Section 12.5
Skill: Knowledge/Comprehension
41) A karyotype reveals that a woman is carrying a fetus that has 47 chromosomes. The test reveals that the genotype of the fetus is XXY. Which of the following statements is correct?
A) The fetus has Down syndrome, and most likely a nondisjunction event occurred in the mother during egg formation.
B) The fetus has Turner syndrome, and most likely a nondisjunction event occurred in the mother during egg formation.
C) The fetus has Klinefelter syndrome.
D) The fetus has an autosomal disorder.
Answer: C
Topic: Section 12.5
Skill: Knowledge/Comprehension
42) What single attribute determines that a human fetus is male?
A) the absence of a second X chromosome
B) the absence of a Y chromosome
C) the presence of a Y chromosome
D) the presence of two X chromosomes
Answer: C
Topic: Section 12.5
Skill: Knowledge/Comprehension
43) Nondisjunction in somatic cells can result in aneuploid cells. This may give rise to:
A) Down syndrome.
B) Turner syndrome.
C) Klinefelter syndrome.
D) cancer.
E) cri-du-chat syndrome.
Answer: D
Topic: Section 12.5
Skill: Knowledge/Comprehension
44) Which of the following combinations of chromosomes would be found in a person afflicted with Turner syndrome?
A) XXY
B) XYY
C) XX
D) XY
E) XO
Answer: E
Topic: Section 12.5
Skill: Knowledge/Comprehension
45) When a fragment breaks from a chromosome and rejoins it, in a flipped orientation, the result is called a/an:
A) deletion.
B) polyploidy.
C) inversion.
D) aneuploidy.
E) translocation.
Answer: C
Topic: Section 12.6
Skill: Knowledge/Comprehension
46) What is a possible cause of the chromosomal aberration called a "duplication"?
A) unequal crossing over
B) exchange between non-homologous chromosomes
C) a chromosome fragment that breaks off and does not rejoin any chromosome
D) breaking of a chromosome fragment, then rejoining in a flipped orientation
E) nondisjunction
Answer: A
Topic: Section 12.6
Skill: Knowledge/Comprehension
47) A karyotype you are viewing shows an extra piece of chromosome 1 attached to chromosome 22. What type of abnormality caused this?
A) inversion
B) deletion
C) translocation
D) nondisjunction
E) sex-linked
Answer: C
Topic: Section 12.6
Skill: Application/Analysis
48) Which of the following is a transfer of genes between non-homologous chromosomes?
A) duplication
B) crossing over
C) inversion
D) deletion
E) translocation
Answer: E
Topic: Section 12.6
Skill: Knowledge/Comprehension
49) Cri-du-chat syndrome babies are mentally challenged and have an abnormal larynx that makes sounds like the cry of a cat. This disorder is due to a/an:
A) deletion in chromosome 5.
B) inversion in chromosome 2.
C) translocation between chromosome 9 and 22.
D) duplication in chromosome 7.
E) trisomy 21.
Answer: A
Topic: Section 12.6
Skill: Knowledge/Comprehension
50) A chromosome that has been broken and has lost a section has had a/an:
A) aneuploidy.
B) inversion.
C) deletion.
D) duplication.
E) translocation.
Answer: C
Topic: Section 12.6
Skill: Knowledge/Comprehension
51) Women do not express X-linked recessive characters.
Answer: FALSE
Topic: Section 12.1
Skill: Knowledge/Comprehension
52) A person must have two alleles for hemoglobin S in order to suffer from sickle-cell anemia.
Answer: TRUE
Topic: Section 12.2
Skill: Knowledge/Comprehension
53) A carrier for a genetic disorder will pass the allele to all of their offspring.
Answer: FALSE
Topic: Section 12.2
Skill: Application/Analysis
54) If one of your parents has Huntington disease and is heterozygous for the disorder, you have a 50 percent chance of inheriting the disease.
Answer: TRUE
Topic: Section 12.2
Skill: Application/Analysis
55) Polyploidy is better tolerated in plants than in animals.
Answer: TRUE
Topic: Section 12.4
Skill: Knowledge/Comprehension
56) A single nondisjunction event results in some gametes with more chromosomes and some gametes with fewer chromosomes.
Answer: TRUE
Topic: Section 12.5
Skill: Knowledge/Comprehension
Match the following.
A) aneuploidy
B) nondisjunction
C) duplication
D) translocation
E) deletion
57) This event may occur during meiosis I or meiosis II.
Topic: Section 12.5
Skill: Knowledge/Comprehension
58) Only 1 percent of human embryos with this condition survive.
Topic: Section 12.5
Skill: Knowledge/Comprehension
59) This produces cri-du-chat syndrome.
Topic: Section 12.6
Skill: Knowledge/Comprehension
60) Non-homologous chromosomes have exchanged parts.
Topic: Section 12.6
Skill: Knowledge/Comprehension
61) This has been involved in producing gene families and has been vital to evolution.
Topic: Section 12.6
Skill: Knowledge/Comprehension
Answers: 57) B 58) A 59) E 60) D 61) C
62) Hemophilia, Duchenne muscular dystrophy, and color blindness are examples of ________ disorders.
Answer: X-linked
Topic: Section 12.1
Skill: Knowledge/Comprehension
63) A person with only one allele for a recessive condition who does not have the condition is called a ________.
Answer: carrier
Topic: Section 12.2
Skill: Knowledge/Comprehension
64) You have studied the presence of a trait in the members of three generations of a family. With this information, you constructed a ________ to track how the trait was passed down through the generations.
Answer: pedigree
Topic: Section 12.3
Skill: Knowledge/Comprehension
65) The condition in which an organism has more than two sets of chromosomes is called ________, while having either more or fewer than the normal number of a particular chromosome is called ________.
Answer: polyploidy; aneuploidy
Topic: Section 12.5
Skill: Knowledge/Comprehension
66) ________ is the condition when an individual has three copies of chromosome 21.
Answer: Down syndrome
Topic: Section 12.5
Skill: Knowledge/Comprehension
67) Explain why a female can be heterozygous for an X-linked gene but a male cannot.
Answer: Females have two X chromosomes and two alleles for all the genes on the X chromosome. A female could be, for example, Aa. A male has only one X chromosome and one allele for each gene on the X chromosome. He cannot be heterozygous.
Topic: Section 12.1
Skill: Knowledge/Comprehension
68) Hemophelia is an X-linked recessive disorder. A mother without the allele and a father with the allele have a daughter. The daughter then marries a man with hemophilia. What is the genotype of the daughter? What is the probability that the daughter's children will develop the disease?
Answer: A Punnett square will show that the daughter must be heterozygous. A Punnett square of the daughter and her husband will show that 50 percent of the children will have the disease.
Topic: Section 12.1
Skill: Application/Analysis
69) Duchenne muscular dystrophy is a recessive disorder resulting in a wasting away of the muscles. How would you design a study to determine if the disorder is X-linked or autosomal? How would you be able to determine if it is X-linked or autosomal?
Answer: The study would analyze the inheritance patterns of a family through many generations, using a pedigree. If phenylkenonuria is X-linked, then more males than females will be affected, an affected son can have parents who are normal, and for a female to have it her father must also have it and her mother must have the disorder or be a carrier. It can also skip generations from grandfather to grandson. If the disorder is autosomal, both males and females are affected equally.
Topic: Section 12.2
Skill: Synthesis/Evaluation
70) Phenylketonuria is the most commonly inherited genetic disorder that affects nervous system development. It occurs in 1 out of every 10,000 births in the United States and Europe. How would you design a study to determine if phenylketonuria is an autosomal dominant or autosomal recessive disorder? How would you be able to determine if it is dominant or recessive?
Answer: The study would analyze the inheritance patterns of a family through many generations, using a pedigree. If the disorder is dominant, affected children usually have an affected parent, and two unaffected parents will not have affected children. If the disorder is recessive, most affected children have unaffected parents, and two affected parents will always have affected children.
Topic: Section 12.3
Skill: Synthesis/Evaluation
71) Explain what causes aneuploidy.
Answer: Nondisjunction is failure of homologous chromosomes or sister chromatids to separate in meiosis. This results in gametes with too few or too many chromosomes. When these participate in fertilization, the zygote that results has too few or too many chromosomes and is aneuploid.
Topic: Section 12.5
Skill: Knowledge/Comprehension
Refer to the figure below, and then answer the question that follows.
72) The last members of the Russian Royal Family were executed during the Russian Revolution. Assume the revolution never took place and Alexis, son of Czar Nicholas II and Alexandra, survived and married into the British Royal Family. What is the probability that his children would have hemophilia? What is the probability his children would be carriers for hemophilia?
Answer: Alexis had hemophilia, which is an X-linked recessive disorder. No one in the British Royal Family had hemophilia, so all have normal alleles. None of Alexis's children would have hemophilia, but 50 percent of his daughters would be carriers.
Topic: Section 12.3
Skill: Application/Analysis
Refer to the figure below, and then answer the question that follows.