Deck 10: Patterns of Inheritance

Question 1

When two alleles of the same gene are identical, the individual carrying those alleles is said to be ____.

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

Answer 1

E

Question 2

An allele is ____ if its effect masks that of a ____ allele paired with it.

A) recessive; codominant
B) codominant; recessive
C) recessive; dominant
D) dominant; recessive
E) incompletely recessive; dominant

Answer 2

D

Question 3

Observable traits are known in genetics as ____.

A) phenotypes
B) genotypes
C) homozygous
D) heterozygous
E) homozygous genotypes

Answer 3

A

Question 4

In cats, short hair ( L ) is dominant to long hair ( l ). If a short-haired cat of unknown genotype is crossed with a long-haired animal, and they produce one long-haired kitten and one short-haired kitten, this would indicate that ____.

A) the short-haired cat was true-breeding
B) the short-haired cat was not true-breeding
C) the long-haired cat was not true-breeding
D) the long-haired cat was heterozygous
E) neither parent was true-breeding

Question 5

In a person with cystic fibrosis, the CFTR mutation causes the protein to be ____.

A) embedded in the plasma membrane
B) destroyed in the endoplasmic reticulum
C) shuttled to the nuclear membrane instead of the plasma membrane
D) shuttled to the plasma membrane instead of the nuclear membrane
E) expelled from the cell by exocytosis before it can do its job

Question 6

Various forms of the same gene are called ____.

A) genotypes
B) alleles
C) somatic
D) recessive
E) phenotypes

Question 7

Red coat is dominant in horses and white coat is recessive. In a cross between a homozygous dominant red-coated horse and a white-coated horse, what genotype(s) would be observed in the offspring?

A) all homozygous recessive
B) all homozygous dominant
C) half homozygous dominant and half homozygous recessive
D) all heterozygous
E) half heterozygous and half homozygous dominant

Question 8

____ raises miscarriage risks by 2-10 percent and is rarely performed.

A) Conventional ultrasound
B) Fetoscopy
C) 4D ultrasound
D) Amniocentesis
E) CVS

Question 9

The mutated gene that causes cystic fibrosis is ____.

A) CFTR
B) CRFT
C) CTFR
D) CRTF
E) CFRT

Question 10

When Gregor Mendel first started his genetics experiments, he ____.

A) knew about the existence of genes
B) knew that some plants "breed true"
C) knew that genes were responsible for observable traits
D) allowed the pea plants to self-fertilize
E) expected all true breeding crosses to produce offspring with intermediate phenotypes

Question 11

When two alleles of the same gene are different, the individual carrying those alleles is said to be ____.

A) recessive
B) heterozygous
C) phenotypic
D) somatic
E) homozygous

Question 12

The most common type of mutation that causes cystic fibrosis is a(n) ____.

A) deletion
B) insertion
C) base-pair substitution
D) gene duplication
E) transformation

Question 13

The failure of which organ affected by a defective CFTR protein is likely to cause death in cystic fibrosis patients?

A) lungs
B) intestines
C) heart
D) liver
E) reproductive system

Question 14

If R is dominant to r , the offspring of the cross of RR with rr will ____.

A) have a unique phenotype
B) have the same phenotype as the RR parents
C) have the same phenotype as the rr parents
D) have the same genotype as the RR parents
E) have the same genotype as the rr parents

Question 15

An individual's ____ determines its observable ____.

A) phenotype; genotype
B) genotype; phenotype
C) gene location; allele
D) heterozygote; homozygote
E) homozygote; heterozygote

Question 16

If tall ( D ) is dominant to dwarf ( d ), and two homozygous varieties DD and dd are crossed, the progeny produced will be____.

A) all intermediate forms
B) all tall
C) all dwarf
D) 1/2 tall and 1/2 dwarf
E) 3/4 tall and 1/4 dwarf

Question 17

____ is the most fatal genetic disorder in the United States.

A) Cystic fibrosis
B) Huntington's disease
C) Sickle-cell anemia
D) Anhidrotic dysplasia
E) Color blindness

Question 18

In the lungs of cystic fibrosis patients, ____.

A) chloride ions are stuck inside epithelial cells
B) water is excessively abundant on epithelial surfaces
C) epithelial surfaces are coated with slippery mucus
D) excess water and chloride ions are pumped out of epithelial cells
E) chloride ions are not transported out of epithelial cells, and epithelial surfaces are dry

Question 19

The main problem for those with cystic fibrosis involves ____.

A) mucus sticking to dry surfaces
B) jerky muscle contractions
C) constant thirst
D) salt accumulations between tissues
E) low pH in tissues preventing proper enzymatic activity

Question 20

A(n) ____ is an offspring of a cross between two individuals that breed true for different forms of a given trait.

A) homozygote
B) recessive
C) hybrid
D) phenotype
E) genotype

Question 21

The mutation that causes the lighter skin color of all people of European descent was the result of a ____ in the gene for a melanin transport protein.

A) base-pair substitution
B) insertion
C) deletion
D) whole chromosome duplication
E) multiple gene mutations involving several mechanisms

Question 22

Genetic recombination as a result of crossing over occurs more readily between genes that are ____.

A) on the sex chromosomes
B) near the centromere
C) located close together on the same chromosome
D) located far apart on the same chromosome
E) located on different chromosomes

Question 23

Purple flower ( A ) is dominant over white flower ( a ), and tall stem ( B ) is dominant over short stem ( b ). The Punnett square represents a cross between two dihybrids ( AaBb   ´   AaBb ).
In the figure above, how many plants would have white flowers and short stems?

A) 1
B) 3
C) 5
D) 9
E) 16

Question 24

Purple flower ( A ) is dominant over white flower ( a ), and tall stem ( B ) is dominant over short stem ( b ). The Punnett square represents a cross between two dihybrids ( A aBb   ´   AaBb ).
In the figure above, how many plants would have purple flowers and tall stems?

A) 1
B) 3
C) 5
D) 9
E) 16

Question 25

Purple flower ( A ) is dominant over white flower ( a ), and tall stem ( B ) is dominant over short stem ( b ). The Punnett square represents a cross between two dihybrids ( AaBb   ´   AaBb ).
In the figure above, what would be the genotype of plant #7?

A) AaBb
B) AABb
C) AaBB
D) AABB
E) aaBB

Question 26

For this problem, you may want to create a Punnett Square on a separate piece of paper. Manuel has cystic fibrosis, a recessive disorder, and sickle-cell anemia, which is also a recessive disorder. Manuel's partner, Lucretia, is normal for both conditions. What is the probability that Manuel and Lucretia will have a normal child without either of the conditions Manuel has?

A) 0  percent
B) 25  percent
C) 75  percent
D) 100  percent
E) It is not possible to solve this problem with the information provided.

Question 27

In cats, short hair L is dominant to long hair l and black hair B is dominant to brown hair b . If you found a black, short-haired cat, you could determine his genotype by crossing it to an animal with a genotype of ____.

A) LLBB
B) llBB
C) llBb
D) llbb
E) LLbb

Question 28

If two individuals who are heterozygous for two traits that display incomplete dominance (e.g., AaBb) mate and have offspring, how many different phenotypes are possible?

A) 1
B) 3
C) 6
D) 9
E) 16

Question 29

Cystic fibrosis is a recessive disorder. If a couple, each of whom is heterozygous for the CFTR mutation, have children, what is the probability that they will have a child with cystic fibrosis?

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

Question 30

Purple flower ( A ) is dominant over white flower ( a ), and tall stem ( B ) is dominant over short stem ( b ). The Punnett square represents a cross between two dihybrids ( AaBb   ´   AaBb ).
In the figure above, what would be the genotype of plant #9?

A) Aabb
B) aaBb
C) AaBB
D) AABB
E) aaBB

Question 31

The ease of detecting and treating ____ is a good example of the advantages of genetic screening.

A) PKU
B) Tay-Sachs
C) Marfan syndrome
D) color blindness
E) Down syndrome

Question 32

The discarded theory of blending inheritance most closely resembles ____.

A) X-linked inheritance
B) dihybridization
C) codominance
D) incomplete dominance
E) complete dominance

Question 33

If a child has an AB blood type, ____.

A) both parents must have different blood types
B) neither parent can have blood type AB
C) both parents must have blood type AB
D) both parents can be any blood type
E) one parent can have blood type O

Question 34

In a Punnett square, the letters on top of the square and on the side of the square represent ____.

A) offspring genotypes
B) zygote genotypes
C) parental gametes
D) offspring phenotypes
E) parental phenotypes

Question 35

For this problem, you may want to create a Punnett Square on a separate piece of paper. Assume brown eyes are dominant to blue eyes and dimples are dominant to no dimples. John has brown eyes, and his mother has blue eyes. John does not have dimples. Zena has blue eyes and also has no dimples. What are the chances if this couple have children, they will produce a child with blue eyes and no dimples?

A) 0
B) ¼
C) ½
D) ¾
E) There is not enough information provided to solve this problem.

Question 36

In codominance, ____.

A) one allele is dominant to another allele
B) the genotype is determined by the phenotype
C) the heterozygous phenotype is intermediate to the homozygous phenotypes
D) the intermediate phenotype may be the result of enzyme insufficiency
E) two alleles may be equally expressed

Question 37

Approximately how many gene products are involved in the synthesis of melanin in humans?

A) 10
B) 25
C) 50
D) 100
E) 1000

Question 38

Purple flower ( A ) is dominant over white flower ( a ), and tall stem ( B ) is dominant over short stem ( b ). The Punnett square represents a cross between two dihybrids ( AaBb   ´   AaBb ).
In the figure above, how many plants would have the genotype AaBb ?

A) 1
B) 3
C) 4
D) 6
E) 9

Question 39

In a cross of a DDRR individual with a ddrr individual, the genotype of all offspring will ____.

A) DDRR
B) DdRR
C) DdRr
D) ddRR
E) ddRr

Question 40

If a pure-breeding wired-hair terrier ( WW ) is crossed with a pure-breeding smooth-hair terrier (ww), and a puppy with a wavy hair is produced, the simplest explanation is ____.

A) a mutation has occurred
B) hair texture is an X-linked trait
C) incomplete dominance
D) hair texture is a lethal trait
E) codominance

Question 41

When genes are located very close together on the same chromosome, ____.

A) gametes usually end up with the same combination of alleles as parental cells
B) gametes usually end up with unique combination of alleles
C) they are inherited separately
D) they often recombine during crossing over
E) offspring will look just like one parent

Question 42

The switching between asexual and sexual reproduction by water fleas is controlled by ____.

A) epistasis
B) pleiotropy
C) incomplete dominance
D) codominant inheritance
E) environmental effects

Question 43

In an autosomal dominant disorder such as Huntington's disease, two carrier parents have the probability of passing the gene onto ____ of their children.

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

Question 44

Narrative:
Achondroplasia, a hereditary form of dwarfism, is an autosomal dominant disorder; however homozygous dominant individuals either die before birth or very shortly thereafter. The homozygous recessive condition is normal. A dwarf couple decide to have children. Use this information to answer the following question:
Of the children of this couple who survive, what is the probability that they will be normal?

A) 0
B) ¼
C) 1/3
D) 2/3
E) ½

Question 45

In a pedigree chart, a male who demonstrates the trait being studied is represented by a ____.

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

Question 46

Narrative:
Achondroplasia, a hereditary form of dwarfism, is an autosomal dominant disorder; however homozygous dominant individuals either die before birth or very shortly thereafter. The homozygous recessive condition is normal. A dwarf couple decide to have children. Use this information to answer the following question:
Of the children of this couple who survive, what is probability that they will be affected by achondroplasia?

A) 0
B) ¼
C) 1/3
D) 2/3
E) ½

Question 47

In the Bombay phenotype, a gene in the recessive condition blocks the expression of A and B red blood cell antigens. Thus, all A, B, and AB genotypes are expressed as the O phenotype. This is an example of ____.

A) complete dominance
B) polygeny
C) incomplete dominance
D) codominance
E) pleiotropy

Question 48

A gene that produces multiple effects is called a(n) ____.

A) codominant gene
B) X-linked gene
C) epistatic gene
D) pleiotropic gene
E) incompletely dominant gene

Question 49

A pleiotropic gene ____.

A) acts on secondary sexual characteristics
B) influences multiple traits
C) is additive
D) produces lethal effects when homozygous
E) produces epigenetic effects

Question 50

The probability of producing a normal child by two parents who are carriers for an autosomal recessive disorder is ____.

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

Question 51

An X-linked carrier is a ____.

A) homozygous dominant female
B) heterozygous female
C) homozygous recessive female
D) homozygous male
E) heterozygous male

Question 52

Geneticists use ____ to study the genetics of families through generations.

A) Punnett squares
B) pedigrees
C) karyotypes
D) DNA profiles
E) fossil analyses

Question 53

The ABO blood types have ____ different genotypes.

A) 4
B) 6
C) 8
D) 12
E) 16

Question 54

An autosomal recessive disorder ____.

A) requires that only one parent be a carrier
B) displays its symptoms in heterozygotes
C) is more frequent in males than females
D) requires that both parents are carriers
E) only affects females

Question 55

Human eye color is an example of a trait that varies ____.

A) according to the geographical area
B) periodically
C) according to humidity
D) continuously
E) according to seasons

Question 56

In humans, skin color is controlled by several genes. Thus, skin color is a(n) ____ characteristic.

A) dominant
B) codominant
C) polygenic
D) pleiotropic
E) recessive

Question 57

In a pedigree chart, a female showing the specific trait being studied is indicated by a ____.

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

Question 58

Six fingers on one hand would be classified as a(n) ____.

A) genetic disorder
B) disease
C) syndrome
D) genetic abnormality
E) illness

Question 59

In Siamese cats, enzymes that code for dark fur color are only active in cooler temperatures. Thus, the tips of a Siamese cat's ears, feet, and tail are dark but not the warmer regions of its body core. This is an example of ____.

A) p leiotropy
B) environmental effects
C) epistasis
D) incomplete dominance
E) codominance

Question 60

Males are more commonly affected by X-linked recessive genetic disorders than females because ____.

A) females have two X chromosomes; therefore, they do not inherit recessive alleles
B) males have only one X chromosome; therefore, they express all recessive X-linked traits
C) males have only one X chromosome; therefore, they have multiple alleles for each X-linked gene
D) Y chromosomes cause X-linked gene mutations
E) males are genetically weaker than females

Question 62

Suppose a single nondisjunction event occurs during anaphase II of meiosis in a normal male cell from meiosis I. Of the resulting sperm, ____.

A) three would be normal and one would have an extra chromosome
B) two would be normal, one would have an extra chromosome, and one would be missing a chromosome
C) two would have an extra chromosome and two would be missing a chromosome
D) all four sperm would have an extra chromosome
E) three would have an extra chromosome and one would be normal

Question 64

Face length in dogs is controlled by ____.

A) a dozen alleles
B) a dozen genes
C) multiple chromosomes
D) sex-linked alleles
E) trisomies

Question 65

The process by which chromosomes fail to separate during meiosis is called ____.

A) aneuploidy
B) trisomy
C) monosomy
D) nondisjunction
E) polyploidy

Question 66

Amniocentesis involves sampling ____.

A) the embryo at the eight-cell stage
B) fetal cells in the amniotic fluid
C) sperm or egg cells
D) fetal skin tissue
E) placental cells

Question 68

____ is an example of a genetic disorder with little impact on the individual.

A) XXX syndrome
B) Turner syndrome
C) Hemophilia
D) XYY syndrome
E) Down syndrome

Question 69

Genetic testing by ____ can be performed earliest in pregnancy.

A) amniocentesis
B) obstetric sonography
C) fetoscopy
D) chorionic villus sampling
E) preimplantation genetic diagnosis