1. How many chromosomes are shown in a normal human karyotype?2 23 44 46 1 2 3 4 5

2. Which of the following are shown in a karyotype?
homologous chromosomes
sex chromosomes
autosomes
all of the above 1 2 3 4 5

3. Which of the following can be observed in a karyotype?
a change in a DNA base
an extra chromosome
genes
alleles 1 2 3 4 5

4. In humans, a male has one X chromosome only. two X chromosomes.
one X chromosome and one Y chromosome.
two Y chromosomes. 1 2 3 4 5

5. Human females produce egg cells that have
one X chromosome.
two X chromosomes.
one X or one Y chromosome.
one X and one Y chromosome. 1 2 3 4 5

6. What is the approximate probability that a human offspring will be female?
10%
25%
50%
75% 1 2 3 4 5

7. What percentage of human sperm cells carry an X chromosome?0%
25%
50%
100% 1 2 3 4 5

8. A human female inherits
one copy of every gene located on each of the X chromosomes.
twice as many sex chromosomes as a human male inherits.
one copy of every gene located on the Y chromosome.
all of the same genes that a human male inherits. 1 2 3 4 5

9. In a pedigree, a circle represents a(an)
male.
female.
child.
adult. 1 2 3 4 5

10. A pedigree can be used to
determine whether a trait is inherited.
show how a trait is passed from one generation to the next.
determine whether an allele is dominant or recessive.
all of the above 1 2 3 4 5

11. Which of the following would you be least likely to see in a pedigree?
All of the symbols are unshaded.
All of the symbols are shaded.
All of the symbols are squares.
About half of the symbols are circles. 1 2 3 4 5

12. Which of the following is caused by a dominant allele?
Huntington’s disease
PKU
Tay-Sachs disease
none of the above 1 2 3 4 5

13. Which of the following is determined by multiple alleles?
Rh blood group
ABO blood group
PKU
Huntington’s disease 1 2 3 4 5

14. A person who has PKU
inherited the recessive allele for the trait from one parent.
inherited the recessive allele for the trait from both parents.
is heterozygous for the trait.
will not pass the allele for the trait to his or her offspring. 1 2 3 4 5

15. Which of the following genotypes result in the same phenotype?
IAIA and IAIB
IBIB and IBi
IBIB and IAIB
IBi and ii 1 2 3 4 5

16. If a man with blood type A and a woman with blood type B produce an offspring, what might be the offspring’s blood type?
AB or O
A, B, or O
A, B, AB, or O
AB only 1 2 3 4 5

17. Which of the following statements is NOT true?
A person with Huntington’s disease might not pass the allele for the disease to his or her offspring.
A person with Huntington’s disease might be homozygous for the disease.
Huntington’s disease is caused by a recessive allele.
A person who inherits one allele for Huntington’s disease will develop the disease. 1 2 3 4 5

18. Sickle cell disease is caused by a
change in one DNA base.
change in the size of a chromosome.
change in two genes.
change in the number of chromosomes in a cell. 1 2 3 4 5

19. In cystic fibrosis, a change in a single gene causes the protein called CFTR to
become less soluble.
fold improperly.
destroy the cell membrane.
transport sodium ions instead of chloride ions. 1 2 3 4 5

20. has a different sequence of amino acids.
Compared with normal hemoglobin, the hemoglobin of a person with sickle cell disease
is longer.
is shorter.
has a different sequence of amino acids.
is wider. 1 2 3 4 5

21. Which of the following does NOT lead to cystic fibrosis?
missing codon in mRNA
shorter CFTR polypeptide chain
point mutation
absence of CFTR in cell membrane 1 2 3 4 5

22. People who are heterozygous for sickle cell disease are generally healthy because
they are resistant to malaria.
they usually have some normal hemoglobin in their red blood cells.
their abnormal hemoglobin usually doesn’t cause their red blood cells to become sickle shaped.
they do not produce abnormal hemoglobin. 1 2 3 4 5

23. The sequencing of human chromosomes 21 and 22 showed that
some regions of chromosomes do not code for proteins.
all of the DNA of chromosomes codes for proteins.
different chromosomes have the same number of genes.
different chromosomes contain the same number of DNA bases. 1 2 3 4 5

24. Alleles found on the same chromosomes
are dominant.
are never separated by recombination.
are linked.
contain repetitive DNA. 1 2 3 4 5

25. The long stretches of repetitive DNA in chromosomes 21 and 22 are unstable sites
that contain genes.
where rearrangements occur.
that cause genetic disorders.
that do not allow crossing-over to occur. 1 2 3 4 5

26. Most sex-linked genes are located on
the autosomes.
the X chromosome only.
the Y chromosome only.
both the X chromosome and the Y chromosome. 1 2 3 4 5

27. Colorblindness is more common in males than in females because
fathers pass the allele for colorblindness to their sons only.
the allele for colorblindness is located on the Y chromosome.
the allele for colorblindness is recessive and located on the X chromosome.
males who are colorblind have two copies of the allele for colorblindness. 1 2 3 4 5

28. Which of the following statements is true?
Females cannot have hemophilia.
The father of a colorblind boy may be colorblind.
A sex-linked allele cannot be dominant.
The mother of a colorblind boy must be colorblind. 1 2 3 4 5

29. Which of the following form(s) a Barr body?
the Y chromosome in a male cell
the X chromosome in a male cell
one of the X chromosomes in a female cell
both of the X chromosomes in a female cell 1 2 3 4 5

30. The formation of a Barr body
causes the genes on one of the X chromosomes in a female cell to be switched off.
always causes the same X chromosome in a female’s cells to be switched off.
switches on the Y chromosome in a male cell.
none of the above 1 2 3 4 5

31. A cat that has spots of only one color
has no Barr bodies.
must be a male.
must be a female.
may be a male or a female. 1 2 3 4 5

32. The failure of chromosomes to separate during meiosis is called
nondisjunction.
X-chromosome inactivation.
Turner’s syndrome.
Down syndrome. 1 2 3 4 5

33. Because the X chromosome contains genes that are vital for normal development, no baby has been born
with one X chromosome.
with three X chromosomes.
without an X chromosome.
with four X chromosomes. 1 2 3 4 5

34. Which of the following combinations of sex chromosomes represents a female?XY
XXY
XXXY XX 1 2 3 4 5

35. If nondisjunction occurs during meiosis,
only two gametes may form instead of four.
some gametes may have an extra copy of some genes.
the chromatids do not separate.
it occurs during prophase. 1 2 3 4 5

36. Nondisjunction can involve
autosomes.
sex chromosomes.
homologous chromosomes.
all of the above 1 2 3 4 5

37. Scientists test for alleles that cause human genetic disorders by
making karyotypes.
making DNA fingerprints.
detecting the DNA sequences found in those alleles.
making pedigrees. 1 2 3 4 5

38. The process of DNA fingerprinting is based on the fact that
the most important genes are different among most people.
no two people, except identical twins, have exactly the same DNA.
most genes are dominant.
most people have DNA that contains repeats. 1 2 3 4 5

39. What conclusion CANNOT be made from two DNA fingerprints that show identical patterns of bands?
The DNA from the two DNA fingerprints almost certainly came from the same person.
The DNA from the two DNA fingerprints definitely came from two different people.
The DNA from the two DNA fingerprints was separated by size.
The DNA repeats that formed the bands in each DNA fingerprint are the same length. 1 2 3 4 5

40. The Human Genome Project is an attempt to
make a DNA fingerprint of every person’s DNA.
sequence all human DNA.
cure human diseases.
identify alleles in human DNA that are recessive. 1 2 3 4 5

41. The human genome was sequenced
by sequencing each gene on each chromosome, one at a time.
using DNA fingerprinting.
by looking for overlapping regions between sequenced DNA fragments.
using open reading frames. 1 2 3 4 5

42. Which of the following information CANNOT be obtained from the Human Genome Project?
causes of genetic disorders
amino acid sequences of human proteins
locations of genes on chromosomes
whether an allele is dominant or recessive 1 2 3 4 5

43. The purpose of gene therapy is to
cure genetic disorders.
determine the sequences of genes.
remove mutations from genes.
change dominant alleles to recessive alleles. 1 2 3 4 5

44. Which of the following is the first step in gene therapy?
splicing the normal gene to viral DNA
allowing recombinant viruses to infect human cells
using restriction enzymes to cut out the normal gene from DNA
identifying the faulty gene that causes the disease 1 2 3 4 5

45. Gene therapy is successful if the
viruses carrying the replacement gene infect the person’s cells.
replacement gene is replicated in the person’s cells.
replacement gene is transcribed in the person’s cells.
replacement gene is successfully spliced to viral DNA. 1 2 3 4 5

46. In a human karyotype, 44 of the chromosomes are autosomes
True
False 1 2 3 4 5

47. In a human karyotype, 23 chromosome pairs are similar in size and shape. _________________________
True
False 1 2 3 4 5

48. In humans, the mother determines the sex of the offspring
True
False 1 2 3 4 5

49. In a pedigree, if a mother is represented by a shaded circle and a father is represented by a shaded square, their children can be represented by either shaded or unshaded circles or squares. _________________________
True
False 1 2 3 4 5

50. A pedigree showing the inheritance of Huntington’s disease within a family would show shaded symbols for people with the disease. _________________________
True
False 1 2 3 4 5

51. If a person has blood type A, he or she cannot receive a blood transfusion from a person with blood type O. _________________________
True
False 1 2 3 4 5

52. Two parents who have Huntington’s disease may produce an offspring who does not have Huntington’s disease. _________________________
True
False 1 2 3 4 5

53. Chromosome 22 contains long stretches of DNA that do not code for proteins. _________________________
True
False 1 2 3 4 5

54. A dominant X-linked trait would be more common in males than in females. _________________________
True
False 1 2 3 4 5

55. If a cat has both orange and black spots, it is homozygous for the alleles on the X chromosome that code for spot color. _________________________
True
False 1 2 3 4 5

56. A person who has Down syndrome has two copies of chromosome 21
True
False 1 2 3 4 5

57. Males generally do not have Barr bodies. _________________________
True
False 1 2 3 4 5

58. DNA fingerprinting analyzes sections of DNA that have little or no known function but are similar from person to person. _________________________
True
False 1 2 3 4 5

59. To locate genes within the human DNA sequence, scientists look for open reading frames within the sequence. _________________________
True
False 1 2 3 4 5

60. Information from the Human Genome Project can be used to learn more about human diseases. _________________________
True
False 1 2 3 4 5

61. Participant Scores Participant 1 Participant 2 Participant 3
Participant 1
Participant 2
Participant 3
Participant 4
Participant 5

62. A(An) ____________________ can be used to determine whether a person has inherited the normal number of chromosomes. 1 2 3 4 5
0 of 5

63. In humans, sex is determined by the X and ____________________ chromosomes.1 2 3 4 5
0 of 5

64. If a couple has five boys, the probability that the next child will be a boy is ____________________. 1 2 3 4 5
0 of 5

65. A(An) ____________________ is a diagram that follows the inheritance of a single gene through several generations of a family. 1 2 3 4 5
0 of 5

66. A person who has ____________________ is unable to break down the amino acid phenylalanine.1 2 3 4 5
0 of 5

67. The alleles IA and ____________________ for the ABO blood group are codominant.1 2 3 4 5
0 of 5

68. A person who has blood type O can receive a blood transfusion only from a person who has blood type ____________________. 1 2 3 4 5
0 of 5

69. People who have sickle cell disease inherited ____________________ copies of the sickle cell allele.1 2 3 4 5
0 of 5

70. A boy who has hemophilia inherited the disorder from his ____________________.1 2 3 4 5
0 of 5

71. A Barr body is a turned-off ____________________ chromosome.1 2 3 4 5
0 of 5

72. A female with the disorder _________________________ inherits only one X chromosome and has the genotype XO. 1 2 3 4 5
0 of 5

73. Nondisjunction in males can lead to the disorder called ______________________________.1 2 3 4 5
0 of 5

74. A person can be tested for the allele that causes Huntington’s disease because the _________________________ of that allele is different from that of the normal allele. 1 2 3 4 5
0 of 5

75. In DNA fingerprinting, the DNA probe that is used is ____________________ to the DNA sequence of the repeats. 1 2 3 4 5
0 of 5

76. The process of _________________________ replaces a faulty gene with a normal working gene.1 2 3 4 5
0 of 5

77. Why are the sex chromosomes considered homologous, even though they vary in size and appearance?1 2 3 4 5
0 of 5

78. What is a pedigree chart?1 2 3 4 5
0 of 5

79. When making a pedigree that shows the inheritance of a recessive allele for a trait within a family, how do you know whether a certain individual should be represented by a shaded symbol? 1 2 3 4 5
0 of 5

80. A person who has type AB blood is sometimes referred to as a universal recipient. Explain why.1 2 3 4 5
0 of 5

81. How is the DNA sequence of the allele that causes cystic fibrosis different from that of the normal allele? 1 2 3 4 5
0 of 5

82. If malaria were eliminated from a certain area, how do you think the frequency of the sickle cell allele in that area would change? Explain 1 2 3 4 5
0 of 5

83. How are human chromosomes 21 and 22 similar?3 4 5
0 of 5

84. Why are all X-linked alleles expressed in males, even if they are recessive?1 2 3 4 5
0 of 5

85. A man who does not have hemophilia and a woman who is a carrier of the disorder have a son. What is the probability that their son has hemophilia? 1 2 3 4 5
0 of 5

86. Why are Barr bodies not found in most male cells?1 2 3 4 5
0 of 5

87. Why is a person who has Klinefelter’s syndrome (XXY) a male, even though he has two X chromosomes in his cells? 1 2 3 4 5
0 of 5

88. Why might different alleles of the same gene produce different fragments when treated with the same restriction enzyme? 1 2 3 4 5
0 of 5

89. Why do scientists use sections of DNA that have little or no known function to do DNA fingerprinting? 1 2 3 4 5
0 of 5

90. What is the goal of the Human Genome Project?1 2 3 4 5
0 of 5

91. Why are viruses used in gene therapy?1 2 3 4 5
0 of 5

92. How might karyotypes be useful to doctors?1 2 3 4 5
0 of 5

93. Why does Huntington’s disease remain in the human population, even though it is fatal and is caused by a dominant allele? 1 2 3 4 5
0 of 5

94. Compare the normal allele for hemoglobin with the sickle cell allele
Compare the normal allele for hemoglobin with the sickle cell allele. How does this difference affect the person’s red blood cells? 1 2 3 4 5
0 of 5

95. Why might it be incorrect to assume that if one chromosome is larger than another, the larger chromosome has more genes? 1 2 3 4 5
0 of 5

96. Explain why the father of a girl who is colorblind must also be colorblind.1 2 3 4 5
0 of 5

97. Compare the inheritance in men and women of a trait coded by a recessive allele on the Y chromosome.1 2 3 4 5
0 of 5

98. What can you conclude if you observe a male cat that has both black and orange spots? Explain your answer 1 2 3 4 5
0 of 5

99. Compare and contrast Turner’s syndrome and Klinefelter’s syndrome.1 2 3 4 5
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100. 0 of 5 Fragment B ACAG Fragment C CAGTCTGATC Fragment A GATCTAGGTCATG
Fragment E
CATGCGATC
Fragment D
AGGTC
Shotgun sequencing was one of the techniques used to sequence the human genome. Below are five DNA fragments¾labeled A, B, C, D, and E, respectively¾that were shotgun sequenced and determined to be part of the same DNA sequence. Notice that the fragments are single stranded. Determine the single-stranded DNA sequence that the fragments below are part of. Explain your reasoning. Fragment A: GATCTAGGTCATG Fragment B: ACAG Fragment C: CAGTCTGATC Fragment D: AGGTC Fragment E: CATGCGATC 1 2 3 4 5
0 of 5

101. Today, people who have hemophilia can be treated by receiving injections of normal clotting proteins. How would gene therapy be more beneficial to these people? Describe the general procedure that would be used 1 2 3 4 5
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