Question 1

A genetically directed deviation from the average is called

Accepted Answer

A)  an abnormality. 
B)  a disorder. 
C)  a syndrome. 
D)  a carrier. 
E)  a pedigree. 
A)  an abnormality. 
B)  a disorder. 
C)  a syndrome. 
D)  a carrier. 
E)  a pedigree.

Question 2

Tay-Sachs disease is most common among

Accepted Answer

A)  Blacks. 
B)  Hispanics. 
C)  Asians. 
D)  Jewish people of Eastern European descent. 
E)  Native Americans. 
A)  Blacks. 
B)  Hispanics. 
C)  Asians. 
D)  Jewish people of Eastern European descent. 
E)  Native Americans.

Question 3

Genes are

Accepted Answer

A)  located on chromosomes. 
B)  inherited in the same way as chromosomes. 
C)  arranged in linear sequence on chromosomes. 
D)  may be exchanged between homologous chromosomes. 
E)  all of these. 
A)  located on chromosomes. 
B)  inherited in the same way as chromosomes. 
C)  arranged in linear sequence on chromosomes. 
D)  may be exchanged between homologous chromosomes. 
E)  all of these.

Question 4

The condition occurring when an organism has a 2 n + 1 chromosome composition is known as

Accepted Answer

A)  monosomy. 
B)  trisomy. 
C)  diploid. 
D)  haploid. 
E)  both trisomy and haploid. 
A)  monosomy. 
B)  trisomy. 
C)  diploid. 
D)  haploid. 
E)  both trisomy and haploid.

Question 5

Which of the following statements is false?

Accepted Answer

A)  The SRY gene is absent in females. 
B)  The SRY gene apparently is the gene that controls the development of male sexuality. 
C)  The development of maleness is by default because males lack two X chromosomes. 
D)  Genes on an X chromosome are called X-linked. 
E)  There is no difference in external genitalia of males or females until four weeks after conception when the genes determining sex begin to be expressed. 
A)  The SRY gene is absent in females. 
B)  The SRY gene apparently is the gene that controls the development of male sexuality. 
C)  The development of maleness is by default because males lack two X chromosomes. 
D)  Genes on an X chromosome are called X-linked. 
E)  There is no difference in external genitalia of males or females until four weeks after conception when the genes determining sex begin to be expressed.

Question 6

In Down syndrome,

Accepted Answer

A)  as the age of the mother increases, the chance of the defect occurring in the unborn children increases. 
B)  the age of the father usually has an equal influence on the defect. 
C)  most embryos abort before complete term. 
D)  a person with the defect cannot have a normal child. 
E)  80% of trisomic 21 babies are born to women over the age of 40. 
A)  as the age of the mother increases, the chance of the defect occurring in the unborn children increases. 
B)  the age of the father usually has an equal influence on the defect. 
C)  most embryos abort before complete term. 
D)  a person with the defect cannot have a normal child. 
E)  80% of trisomic 21 babies are born to women over the age of 40.

Question 7

Aneuploidy would describe all of the following except

Accepted Answer

A)  Turner syndrome. 
B)  Klinefelter syndrome. 
C)  translocation. 
D)  XYY. 
E)  Down syndrome. 
A)  Turner syndrome. 
B)  Klinefelter syndrome. 
C)  translocation. 
D)  XYY. 
E)  Down syndrome.

Question 8

In a pedigree chart, a male showing the specific trait being studied is indicated by a

Accepted Answer

A)  darkened square. 
B)  clear square. 
C)  darkened diamond. 
D)  clear triangle. 
E)  darkened circle. 
A)  darkened square. 
B)  clear square. 
C)  darkened diamond. 
D)  clear triangle. 
E)  darkened circle.

Question 9

Which of the following designates a normal human female?

Accepted Answer

A)  XXY 
B)  XY 
C)  XX 
D)  XYY 
E)  XO 
A)  XXY 
B)  XY 
C)  XX 
D)  XYY 
E)  XO

Question 10

Which of the following designates a normal human male?

Accepted Answer

A)  YY 
B)  XX 
C)  XY 
D)  XO 
E)  XYY 
A)  YY 
B)  XX 
C)  XY 
D)  XO 
E)  XYY

Question 11

Color blindness is an X-linked recessive gene. Two normal-visioned parents produce a color-blind child. 
 (a) Is this child male or female? 
 (b) What are the genotypes of the parents? 
 (c) What are the chances that their next child will be a color-blind daughter?

Accepted Answer

(a) male 
 (b) Cc x

Question 12

Concerning the sex chromosomes, which of the following is correct?

Accepted Answer

A)  The Y chromosome carries a greater number of nonsexual traits. 
B)  X and Y are different in size but carry nearly equal numbers of genes. 
C)  The X chromosome carries more genes for nonsexual traits. 
D)  The X chromosome carries only gender-related genes. 
E)  The X chromosome carries the SRY gene. 
A)  The Y chromosome carries a greater number of nonsexual traits. 
B)  X and Y are different in size but carry nearly equal numbers of genes. 
C)  The X chromosome carries more genes for nonsexual traits. 
D)  The X chromosome carries only gender-related genes. 
E)  The X chromosome carries the SRY gene.

Question 13

A female who is heterozygous for hemophilia will

Accepted Answer

A)  exhibit the condition throughout her life. 
B)  suffer from bleeding when severely stressed. 
C)  show no signs of the disease at all. 
D)  pass the gene on to all of her children. 
E)  pass the gene on to only her sons. 
A)  exhibit the condition throughout her life. 
B)  suffer from bleeding when severely stressed. 
C)  show no signs of the disease at all. 
D)  pass the gene on to all of her children. 
E)  pass the gene on to only her sons.

Question 14

One of the major symptoms of Marfan syndrome is

Accepted Answer

A)  hypertension. 
B)  rupture of the aorta. 
C)  retardation. 
D)  short stature. 
E)  abnormally short arms and legs. 
A)  hypertension. 
B)  rupture of the aorta. 
C)  retardation. 
D)  short stature. 
E)  abnormally short arms and legs.

Question 15

If the gene for yellow body color ( y ) is an X-linked recessive and its dominant counterpart ( y +) produces wild body colors, give the phenotypes expected and their frequencies for the following four crosses: 
 (a) yellow female x wild male 
 (b) wild carrier female x wild male 
 (c) wild carrier female x yellow male 
 (d) homozygous wild female x yellow male

Accepted Answer

(a) yellow male, wild female 
 (b) 1/4 w

Question 16

Karyotype analysis

Accepted Answer

A)  is a means of detecting and reducing mutagenic agents. 
B)  is a surgical technique that separates chromosomes that have failed to segregate properly during meiosis II. 
C)  can be used in prenatal diagnosis to detect chromosomal mutations and genetic disorders in embryos. 
D)  replaces defective alleles with normal ones. 
E)  is used in DNA analysis for paternity. 
A)  is a means of detecting and reducing mutagenic agents. 
B)  is a surgical technique that separates chromosomes that have failed to segregate properly during meiosis II. 
C)  can be used in prenatal diagnosis to detect chromosomal mutations and genetic disorders in embryos. 
D)  replaces defective alleles with normal ones. 
E)  is used in DNA analysis for paternity.

Question 17

If a human recessive X-linked characteristic occurred with a 10 percent frequency, what would its frequency be in males and females?

Accepted Answer

Males 10 p

Question 18

If an embryo doesn't have an exact multiple of the normal haploid number of 23 chromosomes, the condition is known as

Accepted Answer

A)  aneuploidy. 
B)  diploidy. 
C)  ahaploidy. 
D)  multiploidy. 
E)  synploidy. 
A)  aneuploidy. 
B)  diploidy. 
C)  ahaploidy. 
D)  multiploidy. 
E)  synploidy.

Question 19

Tay-Sachs disease

Accepted Answer

A)  is controlled by a simple recessive gene. 
B)  is a sex-linked disease more common in males. 
C)  occurs only in those individuals that receive two copies of a defective recessive gene. 
D)  is the result of the failure of chromosomes to separate so that an individual receives three instead of two chromosomes. 
E)  depends on which parent passes the gene to the child. 
A)  is controlled by a simple recessive gene. 
B)  is a sex-linked disease more common in males. 
C)  occurs only in those individuals that receive two copies of a defective recessive gene. 
D)  is the result of the failure of chromosomes to separate so that an individual receives three instead of two chromosomes. 
E)  depends on which parent passes the gene to the child.

Question 20

Selecting the Exception Four of the five answers listed below are caused by recessive genes. Select the exception.

Accepted Answer

A)  Huntington's disorder 
B)  phenylketonuria 
C)  color blindness 
D)  hemophilia 
E)  albinism 
A)  Huntington's disorder 
B)  phenylketonuria 
C)  color blindness 
D)  hemophilia 
E)  albinism

Exam 20: Chromosomes and Human Genetics

A genetically directed deviation from the average is called

Tay-Sachs disease is most common among

Genes are

The condition occurring when an organism has a 2 n + 1 chromosome composition is known as

Which of the following statements is false?

In Down syndrome,

Aneuploidy would describe all of the following except

In a pedigree chart, a male showing the specific trait being studied is indicated by a

Which of the following designates a normal human female?

Which of the following designates a normal human male?

Color blindness is an X-linked recessive gene. Two normal-visioned parents produce a color-blind child. (a) Is this child male or female? (b) What are the genotypes of the parents? (c) What are the chances that their next child will be a color-blind daughter?

Concerning the sex chromosomes, which of the following is correct?

A female who is heterozygous for hemophilia will

One of the major symptoms of Marfan syndrome is

Karyotype analysis

If a human recessive X-linked characteristic occurred with a 10 percent frequency, what would its frequency be in males and females?

If an embryo doesn't have an exact multiple of the normal haploid number of 23 chromosomes, the condition is known as

Tay-Sachs disease

Selecting the Exception Four of the five answers listed below are caused by recessive genes. Select the exception.

Learning About Human Biology

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