Section 1

Question 1

How many chromosomes are shown in a normal human karotype?
A.2
B.23
C.44
D.46

Answer 1

D.46

Question 2

Which of the following are shown in a karotype?
A. Homologous chromosomes 
B.Sex Chromosomes
C.autosomes 
D.all of the above

Answer 2

D. All of the above

Question 3

Which of the following can be observed in a Karotype? 
A. A change in a DNA base 
B. an extra chromosome 
C.genes
D.alleles

Answer 3

B. an extra chromosome

Question 4

In humans, a male only has....
A. One X chromosome only 
B. two X chromosomes 
C. One X chromosome and one Y chromosome 
D. Two Y chromosome

Answer 4

C.One X chromosome and one Y chromosome

Question 5

Human females produce egg cells that have....
A. One X chromosome
B. Two X chromosomes 
C. One X or one Y chromosome
D. One X and one Y chromosome

Answer 5

A. One X chromosome

Question 6

What is the probability that a human offspring will be female?
A.10%
B.25%
C.50%
D.75%

Answer 6

C.50%

Question 7

What percent of human sperm cells carry an X chromosome?
A.0%
B.25%
C.50%
D.100%

Answer 7

C.50%

Question 8

A human female inherits

a. one copy of every gene located on each of the X chromosomes.
b. twice as many sex chromosomes as a human male inherits.
c. one copy of every gene located on the Y chromosome.
d. all of the same genes that a human male inherits.

Answer 8

a.one copy of every gene located on each of the X chromosomes.

Question 9

In a pedigree, a circle represents a(an)

a. male
b. female.
c. child.
d. adult.

Answer 9

b.female.

Question 10

A pedigree can be used to

a. determine whether a trait is inherited.
b. show how a trait is passed from one generation to the next.
c. determine whether an allele is dominant or recessive.
d. all of the above

Answer 10

d. all of the above

Question 11

Which of the following would you be least likely to see in a pedigree?

a. All of the symbols are unshaded.
b. All of the symbols are shaded.
c. All of the symbols are squares.
d. About half of the symbols are circles.

Answer 11

c. All of the symbols are squares.

Question 12

Which of the following is caused by a dominant allele?

a. Huntington’s disease
b. PKU
c. Tay-Sachs disease
d. none of the above

Answer 12

a.Huntington’s disease

Question 13

Which of the following is determined by multiple alleles?

a. Rh blood group
b. ABO blood group
c. PKU
d. Huntington’s disease

Answer 13

b.ABO blood group

Question 14

A person who has PKU

a. inherited the recessive allele for the trait from one parent.
b. inherited the recessive allele for the trait from both parents.
c. is heterozygous for the trait.
d. will not pass the allele for the trait to his or her offspring.

Answer 14

b.inherited the recessive allele for the trait from both parents.

Question 15

Which of the following genotypes result in the same phenotype?

a. IAIA and IAIB
b. IBIB and IBi
c. IBIB and IAIB
d. IBi and ii

Answer 15

b.IBIB and IBi

Question 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?

a. AB or O
b. A, B, or O
c. A, B, AB, or O
d. AB only

Answer 16

c.A, B, AB, or O

Question 17

Which of the following statements is NOT true?

a. A person with Huntington’s disease might not pass the allele for the disease to his or her offspring.
b. A person with Huntington’s disease might be homozygous for the disease.
c. Huntington’s disease is caused by a recessive allele.
d. A person who inherits one allele for Huntington’s disease will develop the disease.

Answer 17

c.Huntington’s disease is caused by a recessive allele.

Question 18

Sickle cell disease is caused by a

a. change in one DNA base.
b. change in the size of a chromosome.
c. change in two genes.
d. change in the number of chromosomes in a cell.

Answer 18

a.change in one DNA base.

Question 19

In cystic fibrosis, a change in a single gene causes the protein called CFTR to

a. become less soluble.
b. fold improperly.
c. destroy the cell membrane.
d. transport sodium ions instead of chloride ions.

Answer 19

b.fold improperly.

Question 20

Compared with normal hemoglobin, the hemoglobin of a person with sickle cell disease

a. is longer.
b. is shorter.
c. has a different sequence of amino acids.
d. is wider.

Answer 20

c.has a different sequence of amino acids.

Question 21

Which of the following does NOT lead to cystic fibrosis?

a. missing codon in mRNA
b. shorter CFTR polypeptide chain
c. point mutation
d. absence of CFTR in cell membrane

Answer 21

c.point mutation

Question 22

People who are heterozygous for sickle cell disease are generally healthy because

a. they are resistant to malaria.
b. they usually have some normal hemoglobin in their red blood cells.
c. their abnormal hemoglobin usually doesn’t cause their red blood cells to become sickle shaped.
d. they do not produce abnormal hemoglobin.

Answer 22

b.they usually have some normal hemoglobin in their red blood cells.

Question 23

What are multiple alleles?

a. more than two genes that control a trait
b. three or more forms of a gene that code for a single trait
c. three or more chromosomes that determine a trait
d. more than two codominant genes in a chromosome

Answer 23

b.three or more forms of a gene that code for a single trait

Question 24

Why does height in humans have such a wide variety of phenotypes?

a. Height is controlled by at least four genes.
b. The gene for height has only two alleles.
c. Height is controlled by sex-linked genes.
d. Height is controlled by a recessive allele.

Answer 24

a.Height is controlled by at least four genes.

Question 25

``` What controls variations in skin color among humans? A.a person’s diet B.many genes C.multiple alleles of a single gene D.two alleles of a single gene ```

Answer 25

B.many genes

Question 26

Which of these human traits is altered by variations in environment? a. hairline b. height c. smile dimples d. blood type

Answer 26

b.height

Question 27

What factors can affect a person’s height? a. genes only b. both genes and environmental factors c. a person’s blood type d. a person’s karyotype

Answer 27

b.both genes and environmental factors

Question 28

Which combination of sex chromosomes results in a male human being? a. XX b. YY c. XY d. either XX or YY

Answer 28

c.XY

Question 29

How does a geneticist use pedigrees? a. to create genetic crosses b. to replicate identical strings of DNA c. to prove that sex-linked traits are caused by codominant alleles d. to trace the inheritance of traits in humans

Answer 29

d.to trace the inheritance of traits in humans

Question 30

What is a pedigree? a. a chart that tracks which members of a family have a particular trait b. a geneticist who studies the inheritance of traits in humans c. a picture of all of the chromosomes in a cell d. an allele passed from parent to child on a sex chromosome

Answer 30

a.a chart that tracks which members of a family have a particular trait

Question 31

Which genetic disorder causes the body to produce unusually thick mucus in the lungs and intestines? a. hemophilia b. Down syndrome c. cystic fibrosis d. sickle-cell disease

Answer 31

c.cystic fibrosis

Question 32

What is a karyotype? a. a sex-linked genetic disorder b. a picture of a baby before it is born c. a picture of the chromosomes in a cell d. fluid that surrounds a baby before it is born

Answer 32

c.a picture of the chromosomes in a cell

Question 33

What would be the best way to predict the probability of a baby having cystic fibrosis? a. by studying the parents’ karyotypes b. by studying the family’s pedigree chart c. by exploring new methods of genetic engineering d. by determining whether the parents have codominant alleles

Answer 33

b.by studying the family’s pedigree chart

Question 34

Both parents of a child have type A blood. What might their child’s blood type be? a. Type A only b. Type A or type B c. Type A or type O d. Type A or type AB

Answer 34

c.Type A or type O

Question 35

A carrier is a person who has a. one recessive and one dominant allele for a trait. b. two recessive alleles for a trait. c. two dominant alleles for a trait. d. more than two alleles for a trait.

Answer 35

a.one recessive and one dominant allele for a trait.

Question 36

What genetic disorder results in abnormally shaped blood cells? a. hemophilia b. Down syndrome c. cystic fibrosis d. sickle-cell disease

Answer 36

d.sickle-cell disease

Question 37

Many characteristics are affected by interactions between genes and a. chromosomes. b. the environment. c. alleles. d. carriers.

Answer 37

b.the environment.

Question 38

In a human karyotype, 44 of the chromosomes are (autosomes). | True/False

Answer 38

True

Question 39

39. Even if a gene has multiple alleles, a person cannot have more than (three) of those alleles. True/False

Answer 39

False, two

Question 40

Traits that have many different phenotypes, such as height and skin color, are often controlled by a single gene. True/False

Answer 40

False, many genes

Question 41

A male is represented by a square in a pedigree. True/False

Answer 41

True

Question 42

A genetic disorder in which an abnormal form of hemoglobin is produced is hemophilia True/False

Answer 42

False,sickle-cell disease

Question 43

A doctor can look at the chromosomes of a cell in a karyotype. True/False

Answer 43

True

Question 44

A(An) ____________________ can be used to determine whether a person has inherited the normal number of chromosomes.

Answer 44

Karyotype

Question 45

In humans, sex is determined by the X and ____________________ chromosomes.

Answer 45

Y

Question 46

If a couple has five boys, the probability that the next child will be a boy is ____________________.

Answer 46

50%

Question 47

A(An) ____________________ is a diagram that follows the inheritance of a single gene through several generations of a family.

Answer 47

pedigree

Question 48

A person who has ____________________ is unable to break down the amino acid phenylalanine.

Answer 48

PKU

Question 49

The alleles IA and ____________________ for the ABO blood group are codominant.

Answer 49

IB

Question 50

A person who has blood type O can receive a blood transfusion only from a person who has blood type ____________________.

Answer 50

O

Question 51

People who have sickle cell disease inherited _________________ _ copies of the sickle cell allele.

Answer 51

two

Question 52

The three alleles on the single gene that controls blood type are said to be ____________________ alleles.

Answer 52

multiple

Question 53

When many genes control a trait, the trait will show a large number of ____________________.

Answer 53

phenotypes

Question 54

Improvements in ____________________ can alter the effects of genes on height.

Answer 54

diet

Question 55

A person’s surroundings, or ____________________, can change the effects of a person’s genes.

Answer 55

environment

Question 56

An egg that is fertilized by a sperm cell with a(n) ____________________ chromosome will develop into a female.

Answer 56

X

Question 57

A carrier is a person who has one ____________________ allele for a trait.

Answer 57

recessive

Question 58

A(n) ____________________ is used to track the occurrence of a trait in a family.

Answer 58

pedigree

Question 59

People who have the genetic disorder called ____________________ suffer from abnormally low levels of oxygen in the blood.

Answer 59

Sickle-Cell Disease

Question 60

A person who has the genetic disorder called ____________________ bleeds easily.

Answer 60

Hemophilia

Question 61

A karyotype can be used to diagnose the genetic disorder called ____________________.

Answer 61

Down Syndrome

Question 62

A gene is said to have multiple alleles if it has more than ____________________ alleles.

Answer 62

two

Question 63

A karyotype can be used to determine the number of ____________________ in a person’s cells.

Answer 63

chromosomes

Question 64

Two parents who have Huntington’s disease may produce an offspring who does not have the disease. True/False

Answer 64

True

Question 65

In humans, the mother determines the sex of the offspring. True/False

Answer 65

False

Question 66

In a pedigree, if a mother is represented by a shaded circle and a father is represented by a shaded square, and the disorder is caused by a recessive allele, their children cannont be represented by half-shaded circles or squares. True/False

Answer 66

True

Question 67

If a person has blood type A, he or she cannot receive a blood transfusion from a person with blood type O. True/False

Answer 67

False

Question 68

A pedigree showing the inheritance of Huntington’s disease within a family would not show any half-shaded symbols. True/False

Answer 68

True

Question 69

- protein will not carry chloride ions across the membrane a. Huntington’s disease b. Achondroplasia c. Hypercholesterolemia d. Tay-Sachs disease e. Sickle cell disease f. Phenylketonuria g. Colorblindness h. Galactosemia i. Hemophilia j. Cystic Fibrosis k. Duchenne Muscular Dystrophy l. Albinism

Answer 69

j. Cystic Fibrosis

Question 70

- causes eye and liver damage a. Huntington’s disease b. Achondroplasia c. Hypercholesterolemia d. Tay-Sachs disease e. Sickle cell disease f. Phenylketonuria g. Colorblindness h. Galactosemia i. Hemophilia j. Cystic Fibrosis k. Duchenne Muscular Dystrophy l. Albinism

Answer 70

h. Galactosemia

Question 71

- can be placed on a special diet to prevent most effects of the disorder a. Huntington’s disease b. Achondroplasia c. Hypercholesterolemia d. Tay-Sachs disease e. Sickle cell disease f. Phenylketonuria g. Colorblindness h. Galactosemia i. Hemophilia j. Cystic Fibrosis k. Duchenne Muscular Dystrophy l. Albinism

Answer 71

f. Phenylketonuria

Question 72

- lipid accumulation in brain cells a. Huntington’s disease b. Achondroplasia c. Hypercholesterolemia d. Tay-Sachs disease e. Sickle cell disease f. Phenylketonuria g. Colorblindness h. Galactosemia i. Hemophilia j. Cystic Fibrosis k. Duchenne Muscular Dystrophy l. Albinism

Answer 72

d. Tay-Sachs disease

Question 73

- excess cholesterol in the blood a. Huntington’s disease b. Achondroplasia c. Hypercholesterolemia d. Tay-Sachs disease e. Sickle cell disease f. Phenylketonuria g. Colorblindness h. Galactosemia i. Hemophilia j. Cystic Fibrosis k. Duchenne Muscular Dystrophy l. Albinism

Answer 73

c. Hypercholesterolemia

Question 74

- produces physical weakness and damage to brain, heart, and spleen a. Huntington’s disease b. Achondroplasia c. Hypercholesterolemia d. Tay-Sachs disease e. Sickle cell disease f. Phenylketonuria g. Colorblindness h. Galactosemia i. Hemophilia j. Cystic Fibrosis k. Duchenne Muscular Dystrophy l. Albinism

Answer 74

e. Sickle cell disease

Question 75

- 1 out of 100 females are born with this disorder a. Huntington’s disease b. Achondroplasia c. Hypercholesterolemia d. Tay-Sachs disease e. Sickle cell disease f. Phenylketonuria g. Colorblindness h. Galactosemia i. Hemophilia j. Cystic Fibrosis k. Duchenne Muscular Dystrophy l. Albinism

Answer 75

g. Colorblindness

Question 76

- 1 out of 3000 males are born with this disorder a. Huntington’s disease b. Achondroplasia c. Hypercholesterolemia d. Tay-Sachs disease e. Sickle cell disease f. Phenylketonuria g. Colorblindness h. Galactosemia i. Hemophilia j. Cystic Fibrosis k. Duchenne Muscular Dystrophy l. Albinism

Answer 76

k. Duchenne Muscular Dystrophy