Deck 19: Genetics and Inheritance

Question 1

Based on the information below, answer the following three questions, assuming complete dominance.
"In humans, the ability to roll the tongue is a dominant trait;
the inability to roll the tongue is a recessive trait."
If two individuals homozygous dominant for this trait have a child, what is the chance that the child will not be able to roll his tongue?

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

Answer 1

A

Question 2

Variations of homologous genes that result in differences in structure and function are

A) alleles
B) loci
C) autosomes
D) dominant
E) linked

Answer 2

A

Question 3

The law of segregation states that

A) when two identical alleles come together, complete dominance occurs in terms of phenotype
B) genes for different traits assort independently of each other during the formation of egg and sperm
C) genes separate from each other during gamete formation so that each sperm and egg receive only one allele from each pair
D) when different alleles for the same trait come together, one allele will be recessive to another
E) different alleles for the same gene occupy unique loci on sister chromatids

Answer 3

C

Question 4

Place the following in order from smallest, simplest, least complex, to largest and most inclusive:

A) chromosome, gene, genome, nucleotide
B) nucleotide, gene, chromosome, genome
C) genome, chromosome, gene, nucleotide
D) gene, nucleotide, genome, chromosome
E) nucleotide, gene, genome, chromosome

Question 5

Based on the information below, answer the following two questions, assuming complete dominance.
"In humans, a widow's peak is a dominant trait,
and a straight hairline is a recessive trait."
If an individual homozygous dominant for widow's peak has a child with an individual heterozygous for widow's peak, what is the chance that the child will have a homozygous dominant genotype?

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

Question 6

Based on the information below, answer the following three questions, assuming complete dominance.
"In humans, the ability to roll the tongue is a dominant trait;
the inability to roll the tongue is a recessive trait."
If two individuals heterozygous for this trait have a child, what is the chance that the child will not be able to roll his tongue?

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

Question 7

Based on the information below, answer the following three questions, assuming complete dominance.
"In humans, the ability to roll the tongue is a dominant trait;
the inability to roll the tongue is a recessive trait."
If an individual homozygous dominant for this trait has a child with an individual who cannot roll his tongue, what is the chance that the child will have a heterozygous genotype?

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

Question 8

Based on the information below, answer the following two questions, assuming complete dominance.
"In humans, a widow's peak is a dominant trait,
and a straight hairline is a recessive trait."
Cystic fibrosis is a genetic disorder that results from the inheritance of two recessive alleles. What is the chance that a child will inherit the disorder if one parent is heterozygous for this gene and one parent has cystic fibrosis?

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

Question 9

In 2008 the U.S. Congress passed GINA, an act that prevents insurance companies from

A) requiring genetic testing for potential policy holders with a family history of certain types of genetic disorders
B) raising the rates of insurance premiums or denying coverage to people who have a pre-diagnosed health condition
C) increasing insurance costs for healthy individuals based on the results of genetic testing
D) denying insurance coverage to any U.S. citizen
E) refusing to pay for genetic screening of a fetus of a couple considered high risk for certain types of genetic diseases

Question 10

The offspring resulting from a cross between a nearly white horse (cc) and a chestnut-colored horse (CC) is of an intermediate color (between white and chestnut). Which one of the following patterns of inheritance best explains this?

A) complete dominance
B) codominance
C) sex-linked
D) polygenic inheritance
E) incomplete dominance

Question 11

If both alleles of a particular gene are identical, the person is said to be

A) an identical twin
B) phenotypic
C) heterozygous
D) homozygous
E) genotypic

Question 12

The Punnett square is a useful tool for

A) determining the rate of segregation of alleles
B) calculating how many mutations occur during DNA replication
C) determining which genes or traits assort independently during gamete formation
D) predicting the ratios of possible genotypes of a particular combination of alleles
E) predicting the level of crossing over that will occur during meiosis

Question 13

In polygenic inheritance,

A) all individuals in the population are initially heterozygous for a particular trait
B) the environment has no influence in phenotype expression
C) the genotype makeup of individuals in a population is the only factor influencing phenotypes
D) multiple alleles and genes contribute to a phenotype
E) all traits are expressed as incomplete dominance

Question 14

Based on the information below, answer the following two questions, assuming complete dominance.
"In humans, a widow's peak is a dominant trait,
and a straight hairline is a recessive trait."
If an individual homozygous dominant for widow's peak has a child with an individual heterozygous for widow's peak, what is the chance that the child will have a widow's peak?

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

Question 15

Which one of the following is TRUE regarding an individual who has inherited one sickle-cell gene and one normal gene for hemoglobin?

A) The individual will develop sickle-cell anemia.
B) The individual will produce only abnormal hemoglobin.
C) The individual is more likely to resist malaria than an individual with two normal genes for hemoglobin.
D) The individual will most likely die before the age of 10 from complications associated with abnormal white blood cells.
E) The individual has the homozygous recessive genotype for this trait.

Question 16

A father is blood type B and a mother is blood type A. They have a child with blood type O. What are the genotypes of the father and mother?

A) The father must be BB and the mother must be AO.
B) The father must be BO and the mother must be AA.
C) The father must be BO and the mother must be AO.
D) The father must be BB and the mother must be AA.
E) This isn't possible.

Question 17

Which of the following human traits is an example of codominance?

A) sickle-cell anemia
B) variation in eye color
C) human height
D) AB blood type
E) both sickle-cell anemia and AB blood type

Question 18

Based on the information below, answer the following two questions.
"The color of the four-o'clock flower is as follows:
homozygous dominant-red
homozygous recessive-white"
If flower color of the offspring was 25% white and 75% red, and was inherited by complete dominance, the parents' genotypes must be

A) all red
B) one homozygous dominant, the other heterozygous
C) both heterozygous
D) one homozygous recessive, the other heterozygous
E) both homozygous dominant

Question 19

An example of a genotype is

A) attached earlobes
B) homozygous dominant
C) brown hair color
D) long fingers
E) blood type AB

Question 20

Based on the information below, answer the following two questions.
"The color of the four-o'clock flower is as follows:
homozygous dominant-red
homozygous recessive-white"
The flower color in this plant is inherited by incomplete dominance. If a flower homozygous dominant for flower color is crossed with a white flower, the color of the offspring flowers will be expected to be

A) all red
B) all pink
C) all white
D) 50% white and 50% pink
E) 50% white and 50% red

Question 21

Which one of the following syndromes results in an individual with a nearly normal female phenotype and a tendency to develop mild mental retardation?

A) Trisomy-X syndrome
B) Klinefelter syndrome
C) Double-Y syndrome
D) Turner syndrome
E) Trisomy-Y syndrome

Question 22

Genes represent the set of instructions for the expression of one or more traits human beings and influence human behaviors by

A) directly causing specific changes in mood or patterns of behavior
B) producing protein products that serve as switches for directly turning on or off certain behaviors
C) directing the synthesis of protein products that influence but do not directly cause most human behaviors
D) activating behavior pathways, like those leading to depression or happiness
E) functioning as specific behavior suppressors

Question 23

Which of the following is characteristic of Klinefelter syndrome?

A) sterility and mild mental impairment
B) female phenotype
C) XYY genotype
D) nondisjunction of chromosomes after fertilization
E) trisomy 18 genotype

Question 24

If a piece of chromosome breaks off during mitosis or meiosis and does not reattach, the event is called

A) nondisjunction
B) translocation
C) dysplasia
D) nondysplasia
E) a deletion

Question 25

Polygenic traits display phenotypes that

A) are most commonly reflective of the heterozygous condition
B) usually express the dominate condition in greater than 75% of the population
C) represent a continuous range within the population
D) often are lethal to second generation of children
E) are masked by a codominance condition

Question 26

Which one of the following genetic disorders is caused by the inheritance of a dominant-lethal allele?

A) Down syndrome
B) hemophilia
C) Huntington's disease
D) muscular dystrophy
E) Klinefelter syndrome

Question 27

Red-green color blindness is an X-linked recessive disorder. Assume that a mother is a carrier and a father is color-blind. What is the chance that their son will inherit red-green color blindness?

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

Question 28

The trend toward increased height and weight due to improved nutrition in certain human populations is an example of the effect of ________ on phenotypes.

A) gene linkage
B) the environment
C) codominance
D) polygenic inheritance
E) genetic disorders

Question 29

A phenotypic trait is considered sex-linked when

A) a trait occurs only in males
B) the genes for the phenotype occur on X or Y chromosomes
C) the phenotype is expressed only after sexual intercourse
D) the phenotype occurs only in females
E) the phenotype is polygenic for both sexes

Question 30

A recessive allele associated with chromosome 15 causes an enzyme deficiency disease called

A) Tay-Sachs
B) PKU
C) Patau syndrome
D) Turner syndrome
E) Edwards syndrome

Question 31

A couple has a daughter who is color-blind. The mother is not color-blind, but the father is. What is the genotype of the mother for this trait?

A) two dominant alleles
B) one dominant allele, one recessive allele
C) three dominant alleles
D) one abnormal Y chromosome, one normal X chromosome
E) two recessive alleles

Question 32

Alterations in chromosome number can occur with any chromosome, but most alterations are not seen in human populations because

A) the phenotype is homozygous recessive
B) the phenotype is expressed in a continuous range in a given population and thus does not stand out
C) they are lethal during fetal development
D) most are corrected during the first mitotic event in the fertilized egg
E) the genotype still represents a normal condition

Question 33

Which of the following genotypes results in a female phenotype?

A) XY
B) XYY
C) XO
D) XXY
E) both X and XXY

Question 34

Cystic fibrosis is the most common fatal genetic disease in North America and results in what type of allele located on chromosome 7?

A) recessive
B) dominant
C) homozygous
D) heterozygous
E) polygenic

Question 35

When a piece of chromosome breaks off and reattaches at another site on the same or another chromosome, this is called

A) a deletion
B) nondisjunction
C) translocation
D) nontranslation
E) recombination

Question 36

A couple is planning to have a child. The female is a carrier for hemophilia; the male does not have hemophilia. What is the chance that a female child will never develop hemophilia?

A) 0%
B) 25%
C) 33%
D) 50%
E) 100%

Question 37

Which of the following is most likely involved in the determination of intelligence?

A) one gene
B) multiple genes
C) the environment
D) one gene and the environment
E) multiple genes and the environment

Question 38

Failure of sister chromatids to separate properly is called

A) segregation
B) nondisjunction
C) crossing-over
D) hemophilia
E) translocation

Question 39

A person born with Edwards syndrome has a genotypic condition identified as

A) trisomy 21
B) trisomy 18
C) nondisjunction
D) XO
E) XXY

Question 40

What is the significance of crossing-over, independent assortment, and random fertilization?

A) an increase in the number of gametes produced by an individual, thereby increasing the chance that fertilization will occur
B) an increase in the genetic diversity of gametes and zygotes
C) an increase in the number of daughter cells produced by mitosis, thus providing a mechanism for rapidly repairing injured tissues
D) a decrease in the genetic complexity of living systems, making it more likely that a species will survive
E) a decrease in the amount of time it takes to produce gametes

Question 41

In the human male, genotype and phenotype associated with the genes on the X chromosome are determined by the one X chromosome he inherits from his mother.

Question 42

Polygenic inheritance depends on gene products from multiple genes.

Question 43

Genes for different traits located on the same chromosome are called ________.

Question 44

In incomplete dominance, the phenotype of the heterozygous genotype is an intermediate between the phenotype of either homozygous genotype.

Question 45

If the two alleles of a particular gene pair are the same, the individual is ________ for that gene.

Question 46

If alleles for the same gene are different in the same person, that individual is heterozygous for the trait.

Question 47

A(n) ________ refers to the complete set of genes in the chromosomes of an individual.

Question 48

In ________, the phenotype of the heterozygous genotype is an intermediate between the phenotype of either homozygous genotype.

Question 49

Mendel's law of independent assortment states that genes separate from each other during gamete formation so that each sperm or egg gets only one unit of each pair.

Question 50

A deletion occurs when a piece of chromosome breaks off and is lost.

Question 51

A Punnett square can be used to determine possible genotypes of offspring as well as possible genotypic and phenotypic ratios of the offspring given a particular combination of alleles.

Question 52

Linked genes are not influenced by crossing-over during meiosis.

Question 53

According to Mendel's law of ________, genes of a gene pair separate from one another during the formation of gametes.

Question 54

A recessive trait can be inherited through complete dominance only if both parents are heterozygous for the trait.

Question 55

Alleles are alternative versions of chromosomes.

Question 56

A phenotype is determined by ________ and ________.

Question 57

Alternative versions of the same gene are ________.

Question 58

The inheritance of a trait that is determined by many genes acting together is ________ inheritance.

Question 59

Identify the mode of inheritance for each of the following traits.

A) incomplete dominance
B) codominance
C) nondisjunction
D) sex-influenced trait
E) polygenic inheritance
F) X-linked inheritance
G) inheritance of a dominant-lethal allele
1) Huntington disease
2) red-green color blindness
3) baldness
4) AB blood type
5) Down syndrome
6) straight vs. curly vs. wavy hair in humans
7) human eye color

Question 60

Sickle-cell anemia is a disease that alters the structure of hemoglobin, and in turn, can cause severe health problems in individuals if left untreated. The disease is expressed in homozygous recessive individuals, whereas the heterozygous condition usually does not result in any symptoms of the disease. Sickle-cell anemia primarily affects Africans and Caucasians of Mediterranean descent. Typically, when a disease occurs only in the homozygous recessive condition, the incidence of the gene in the population is predicted to decline overtime, particularly when it can be detected either phenotypically or by genetic testing. In East Africa, the disease still occurs in about 40% of the population. Give an explanation for why the incidence of the disease has remained so high in African populations.

Question 61

Failure of homologous chromosomes or sister chromatids to separate properly is called ________.

Question 62

During embryological development, if a certain gene on the ________ chromosome is activated during the sixth or seventh week of development, the embryo will develop into a male.

Question 63

Explain why in some cases, linked genes may be separated during crossing-over, yet at other times, linked genes are not affected by the recombination during meiosis.

Question 64

For several phenotypes in the human population, it is clear that more than just the genotype is influencing the expression of the trait. Analysis of human populations indicates that height and weight are examples of phenotypes under environmental influence as well as genotype. Provide evidence that would support the contention that both environment and genotype influence human weight.

Question 65

________ testing refers to the analysis of an individual's genetic material to determine predisposition to a particular health condition.

Question 66

A(n) ________ occurs when a piece of chromosome breaks off or is lost.

Question 67

Genes located on the same chromosome are not always inherited together because of the process of ________, which occurs during meiosis; this process "reshuffles" the genes.

Question 68

An individual who inherits three copies of chromosome 18 will develop ________ syndrome.

Question 69

A display of an individual's chromosomes is known as a(n) ________.

Question 70

The process by which a piece of a chromosome breaks off and then attaches to another chromosome is referred to as ________.