Deck 11: The Basic Principles of Heredity

Question 1

Mating a pure-bred pink rose plant with a pure-bred pink rose plant will produce

A) plants with pink, red, and white roses.
B) plants with only pink roses.
C) plants with red or white roses in a 3:1 ratio.
D) plants with white or red roses in a 3:1 ratio.
E) plants with only red roses.

Answer 1

B

Question 2

The height of pea plants from a cross between parent plants heterozygous for height, in which tall is dominant, would be

A) all short.
B) all tall.
C) 1 tall: 3 short.
D) 2 short: 2 tall.
E) 3 tall: 1 short.

Answer 2

E

Question 3

If an allele is dominant, then

A) its phenotype is only expressed in heterozygous individuals.
B) its phenotype is expressed only in homozygous individuals.
C) its phenotype masks the expression of the recessive allele in a hybrid.
D) its phenotype is always expressed in all generations.
E) its phenotype is more beneficial than the recessive phenotype.

Answer 3

C

Question 4

___________ were originally designated the location of a particular gene on the chromosome.

A) Loci
B) Genotypes
C) Phenotypes
D) Alleles
E) Homozygous

Question 5

Mendel's principle of segregation states that

A) alleles from one parent mask the expression of alleles from the other parent.
B) alleles separate from each other before forming gametes.
C) hybrids will express a phenotype intermediate between the two parental phenotypes.
D) true-breeding parents produce offspring of the same phenotype.
E) dominant and recessive alleles segregate during meiosis.

Question 6

The physical location of a gene on a chromosome is called

A) an allele.
B) its locus.
C) a trait.
D) a chromatid.
E) its genotype.

Question 7

Which of the following represents the possible genotype(s) resulting from a cross between one homozygous (BB) individual and one heterozygous (Bb) individual?

A) BB and Bb
B) BB, Bb, and bb
C) BB only
D) Bb only
E) bb only

Question 8

Alternative forms of a gene are called ___________.

A) alleles
B) homozygous
C) phenotypes
D) genotypes
E) loci

Question 9

Scientists use the term ____________ to refer to the genetic makeup for that organism.

A) allele
B) phenotype
C) homozygous
D) locus
E) genotype

Question 10

A pear plant with the genotype Aa can produce gametes containing

A) either A or Aa.
B) only the dominant A.
C) only the recessive a.
D) either A or a.
E) either AA, Aa, or aa.

Question 11

Which of the following represents the possible genotype(s) resulting from a cross between a heterozygous individual (Bb) and one that is homozygous (bb)?

A) BB and Bb
B) Bb and bb
C) BB only
D) Bb only
E) bb only

Question 12

A mating between individuals with different alleles at two loci is known as?

A) Parent cross
B) Plant breeders cross
C) Test cross
D) Dihybrid cross
E) Monohybrid cross

Question 13

The chromosome theory of inheritance, developed by Sutton and Boveri, provided an explanation for Mendel's principle of segregation by proposing that

A) sister chromatids separate during mitosis.
B) all genes are linked on a single chromosome.
C) linked genes are inherited together.
D) homologous chromosomes segregate during meiosis.
E) homologous chromosomes segregate during mitosis.

Question 14

____ are alternative forms of a gene that govern the same feature, such as eye color, and occupy corresponding positions on homologous chromosomes.

A) Alleles
B) Loci
C) Homozygotes
D) Coupled traits
E) Heterozygotes

Question 15

The physical appearance of an organism for a given trait is known as

A) genetics.
B) dominance.
C) synapsis.
D) genotype.
E) phenotype.

Question 16

In Mendel's Experiment Results for Seven Characters, what was the dominant trait for pod color of the peas?

A) White
B) Green
C) Purple
D) Grey
E) Yellow

Question 17

A heterozygous fruit fly with normal wings and a gray body (VvBb) is crossed with homozygous flies with vestigial wings and black bodies (vvbb). This type of cross is known as a

A) monohybrid cross.
B) dihybrid cross.
C) polytropic cross.
D) true breeding cross.
E) chromosomal cross.

Question 18

Which of the following does NOT describe Mendel's research and proposed Model of Inheritance?

A) Each individual has two sets of factors, one of each pair inherited from the mother and one from the father.
B) Hybrid offspring with intermediate characteristics were not extensively studied.
C) Factors may be expressed, hidden in a given generation or lost.
D) Observations were limited to traits that are governed by two alleles.
E) Because of meiosis, which was discovered after Mendel's time, each parent passes one set of factors to each offspring.

Question 19

Mating an individual expressing a dominant phenotype, but whose genotype is unknown, with an individual expressing the corresponding recessive phenotype is an example of a(n)

A) heterozygous cross.
B) F₁ cross.
C) F₂ cross.
D) parental cross.
E) test cross.

Question 20

A lizard with a striped tail and a normal head is crossed with one having a normal tail and a spotted head. All the F₁ progeny are normal (no stripes or spots). What progeny are expected from a cross of the F₁ progeny? Assume that the genes conferring stripes and spots were on different chromosomes.

A) Equal numbers of normal, striped, spotted and striped, and spotted
B) 3 striped : 1 spotted
C) 9 striped and spotted : 3 spotted : 3 striped : 1 normal
D) 9 striped : 3 spotted : 1 striped or spotted
E) 9 normal : 3 striped : 3 spotted : 1 striped and spotted

Question 21

What are the predicted phenotypes of the female children from the union of a woman who is heterozygous for hemophilia and a man who has normal blood clotting characteristics? (Use the Punnett square to verify your answer.)

A) All female children will be carriers.
B) 3 homozygous healthy:1 carrier
C) 1 homozygous healthy:1 carrier
D) 1 hemophilia:2 homozygous healthy:1 carrier
E) All female children will have hemophilia.

Question 22

The sex of most mammals, birds, and insects is determined by

A) the temperature.
B) the external environment.
C) sex chromosomes.
D) parental age.
E) the internal environment.

Question 23

The cells of female mammals, including humans, contain two __________.

A) autosomes
B) XY chromosomes
C) XX chromosomes
D) Y chromosome
E) X chromosomes

Question 24

Blood types A, B, AB, and O are controlled by how many alleles representing a single locus?

A) Five
B) Nine
C) Three
D) Seven
E) Eight

Question 25

What is the probability that two lizards heterozygous for stripes on their tails (Ss) will produce homozygous offspring with no stripes (ss)?

A) 1
B) 1/2
C) 1/4
D) 1/8
E) 0

Question 26

If a couple is planning on having two children, what is the probability that both will be male?

A) 0
B) 1/4
C) 1/2
D) 3/4
E) 1

Question 27

The sex of a human is determined by the

A) number of chromosomes.
B) number of autosomes.
C) presence of only one X chromosome.
D) number of sex chromosomes.
E) presence of a Y chromosome.

Question 28

A couple who does not have cystic fibrosis but are both heterozygous has already had three girls with cystic fibrosis, and are hoping to have a healthy child for their fourth. What are the chances that the fourth child will be a healthy male?

A) 0
B) 1/8
C) 1/4
D) 3/8
E) 1/2

Question 29

A heterozygous fruit fly with normal wings and a gray body ( VvBb ) is crossed with homozygous flies with vestigial wings and black bodies ( vvbb ). Out of 800 total F₁ progeny, 296 are normal gray, 328 are vestigial black, 99 are normal black, and 77 are vestigial gray. What is the best explanation for this result?

A) The loci for wing length and body color are on different chromosomes.
B) The loci for wing length and body color are on sex chromosomes.
C) The loci for wing length and body color are on the same chromosome.
D) Mendel's principle of independent assortment accounts for this.
E) Mendel's principle of segregation accounts for this.

Question 30

What are the possible genotypes of a female child from the union of a woman who is heterozygous for hemophilia and a man who has normal blood clotting characteristics?

A) X^HX^H or X^HX^h
B) X^HX^h
C) X^HY^H
D) Hh
E) HH

Question 31

A Barr body in a mammalian female cell represents a(n)

A) inactivated oocyte.
B) polar body.
C) degenerate nucleus.
D) inactivated X chromosome.
E) inactivated Y chromosome.

Question 32

What are the predicted phenotypes of the male children from the union of a woman who is heterozygous for hemophilia and a man who has normal blood clotting characteristics? (Use the Punnett square to verify your answer.)

A) All male children will be healthy.
B) 3 healthy:1 hemophilia
C) 1 hemophilia:1 healthy
D) 1 hemophilia:3 healthy
E) All male children will have hemophilia.

Question 33

Which of the following refers to the expression of an intermediate phenotype in heterozygous individuals?

A) Pleiotropy
B) Incomplete dominance
C) Complete dominance
D) Codominance
E) Dihybrid cross

Question 34

Color blindness is more common in males than in females because

A) females need to inherit only one copy of the recessive color blindness allele to express the trait.
B) males only need to inherit the recessive maternal color blindness allele to be color blind.
C) Color blindness is an autosomal trait.
D) all females are hemizygous for the color blindness trait.
E) males can only inherit paternal color blindness alleles.

Question 35

In genetics, map units express the distance between

A) chromosomes during metaphase.
B) two loci on a chromosome.
C) alleles.
D) polar bodies.
E) homologous chromosomes.

Question 36

Which describes the interaction between genes such that the presence of certain alleles in one locus affects the expression of certain alleles in the other locus?

A) Pleiotropy
B) Epistasis
C) Polygenic inheritance
D) Norm of reaction
E) Codominance

Question 37

All calico cats are female because

A) two recessive X-linked genes are required for the calico phenotype.
B) Y-linked genes prevent the expression of the calico phenotype.
C) the calico phenotype is caused by random X chromosome inactivation.
D) the calico phenotype is a Y-linked trait.
E) one X chromosome and one Y chromosome are needed for the expression of the calico phenotype.

Question 38

Two Martians fall in love and marry. One Martian is homozygous for red eyes and the other is heterozygous. The recessive eye color is purple. What is the probability that they will have a child with purple eyes (assuming Martians have similar genetics to humans)?

A) 1/1
B) 1/2
C) 1/4
D) 3/4
E) 0

Question 39

The ability of a single gene to have multiple effects is known as _____.

A) pleiotropy
B) epistasis
C) polygenic inheritance
D) norm of reaction
E) codominance

Question 40

If a couple is planning on having three children, what is the probability that only one will be male?

A) 0
B) 1/4
C) 3/8
D) 1/2
E) 3/4

Question 41

In rabbits, coat color is governed by four alleles: C for dark gray, C^ch for chinchilla, C^h for Himalayan, and c for white. This is an example of

A) X-linked genes.
B) multiple alleles.
C) epistasis.
D) codominance.
E) incomplete dominance.

Question 42

The range of phenotypic possibilities that can develop from a certain dog genotype under different environmental conditions is called the

A) epistatic interaction.
B) norm of reaction.
C) nurture limit.
D) genotype range.
E) maximum phenotype.

Question 43

The color of certain genetically identical hydrangea flowers ranges from blue to purple to pink, depending on the level of aluminum in the soil. In which of the following types of soil is aluminum less soluble, and the flowers pink?

A) Silty soils
B) Clay soils
C) Peaty soils
D) Saline soils
E) Alkaline soils

Question 44

A ____ is best used to demonstrate the linkage of two genes.

A) monohybrid cross
B) dihybrid cross
C) monohybrid test cross
D) two-allele test cross
E) two-point test cross

Question 45

A gene that affects, prevents, or masks the expression of a gene at another locus is a(n) ____ gene.

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

Question 46

A gene that controls seed coat color in peas also determines the susceptibility of these peas to a particular disease. This situation is referred to as

A) variegation.
B) polygenic inheritance.
C) codominance.
D) pleiotropy.
E) incomplete dominance.

Question 47

Compare the following pairs of related terms: codominance and incomplete dominance; epistasis and polygenic inheritance.

Question 48

When true breeding red tulips are crossed with true breeding white tulips, the progeny have pink flowers. This is an example of

A) incomplete dominance.
B) codominance.
C) pleiotropy.
D) epistasis.
E) norm of reaction.

Question 49

The offspring of two heterozygous gray-bodied, normal-winged flies should be 50% gray-bodied/normal wings (BbRr) and 50% black-bodied/vestigial wings (bbrr) because these alleles are linked. Suppose a small number, say 15%, of the offspring are instead black-bodied with normal wings. This is most likely the result of

A) crossing-over.
B) incomplete dominance.
C) codominance.
D) an error in meiosis.
E) mutation.

Question 50

A cross of two medium height hybrid plants produces offspring that are dwarf, medium, and tall in a ratio of 1:2:1. This is an example of

A) variegation.
B) hybrid vigor.
C) incomplete dominance.
D) epistasis.
E) a polygenic trait.

Question 51

The zygote and early embryonic cells of female mammals have how many X chromosomes?

A) Three
B) One
C) Two
D) Five
E) Seven

Question 52

The probability that two genes will be separated by crossing-over is related to

A) the phenotype that they control.
B) how far the two genes are from the centromere.
C) the distance between the two genes on the chromosome.
D) whether the two genes are located on a sex chromosome.
E) how far the genes are from the kinetochore.

Question 53

____ refers to multiple independent pairs of genes having similar and additive effects on the same characteristic.

A) Codominance
B) Epistasis
C) Polygenic inheritance
D) Complete dominance
E) Additive dominance

Question 54

In rabbits, coat color is governed by four alleles: C for dark gray, C^ch for chinchilla, C^h for Himalayan, and c for white. Each individual rabbit inherits a combined total of _____ coat color allele(s) from its parents.

A) zero
B) one
C) two
D) three
E) four

Question 55

In a two-point test cross, 36 of the offspring were recombinant types. The remaining 64 offspring were parental types. How many map units separate the two loci?

A) 28
B) 36
C) 64
D) 78
E) 100

Question 56

An organism with the genotype of AaXx can produce gametes containing ____ if the two genes are unlinked.

A) Aa or Xx
B) AX, Ax, aX, or ax
C) AaXx only
D) AX or ax
E) A, a, X, or x

Question 57

Which of the following statements about dosage compensation is false?

A) X chromosome inactivation is a random event in each somatic (body) cell of the female embryo.
B) Each X chromosome carries a genetic region called the X chromosome inactivation center (XIC).
C) Male fruit flies accomplish this by making their single X chromosome more active.
D) Dosage compensation is a mechanism that makes equivalent the two doses in the male and the single dose in the female.
E) Because of dosage compensation, males and females produce the same amounts of proteins.

Question 58

Breeding a yellow dog with a brown dog produced puppies with both yellow and brown hairs intermixed. This is an example of

A) variegation.
B) codominance.
C) incomplete dominance.
D) epistasis.
E) a polygenic trait.

Question 59

What are the possible phenotypes of the children if the mother has Type O blood and the father has type AB blood? (Use the Punnett square to verify your answer.)

A) AB only
B) A, B
C) A, AB
D) A, B, AB
E) A, B, O

Question 60

What is dosage compensation with respect to the sex chromosomes? Briefly explain how this is accomplished in humans.

Question 61

A male is neither homozygous nor heterozygous for his X-linked alleles; instead, he is always hemizygous.

Question 62

The presence of two X chromosomes supports the existence of a genetic locus.

Question 63

In humans, a mutation in the phenylalanine hydroxylase gene causes phenylketonuria (PKU), which is characterized by a wide variety of medical problems. This is an example of epistasis.

Question 65

The debate over nature versus nurture in determining certain human characteristics can be explained by pleiotropic genes.

Question 66

A female black cat mated with an albino male and gave birth to six black kittens. When the albino male was mated with a different female black cat, three black cats and two albino cats were produced. How can you explain this pattern of heredity? Write genotypes for all three parental cats and offspring.

Question 68

If a cell has two X chromosomes, XIST will become active in one of them, producing a special type of regulatory RNA molecule known as long noncoding RNA..

Question 70

A test cross is performed to determine phenotype.

Question 71

Briefly explain why color blindness affects men more than women and its mechanism of inheritance.

Question 72

The product rule is used to determine the probability that two parents with a Bb genotype will have a child who also has the Bb genotype.

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Question 73

You want to determine if black coat color (B) and long tail length (T) are linked in a new breed of dog (white coat and short tails are recessive). Design a two-point test cross to determine if this is indeed the case. What results would you expect if the genes were linked? What would you expect if the alleles sorted independently?

Question 74

Suppose that the allele for brown eyes (B) is dominant to the allele for blue eyes (b). If both parents have brown eyes and are heterozygous (Bb), what are the chances that their first child will have blue eyes? Brown eyes? What are the chances that if they have two children, both will have blue eyes?

Question 75

The theory of blending inheritance was shown to be false by Mendel's observations of dominant and recessive alleles.

Question 77

Dominant traits remove recessive traits when both are present in the same individual.

Question 78

Dosage compensation is defined as the genetic phenomenon that allows females, who carry two copies of an X-linked gene, to have a phenotype that is equivalent to that of males, who only have one copy of the X-linked gene.

Question 79

Mendel's principle of independent assortment describes the separation of paired factors during the formation of gametes.

Question 80

Genotype can always be inferred from phenotype.