Deck 11: The Basic Principles of Heredity

Question 1

A lizard with a striped tail and a normal head is crossed with one having a normal tail and a spotted head. All of the F₁ progeny are normal (no stripes or spots). What progeny would be expected to be produced by mating the F₁ progeny with each other, if 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

Answer 1

E

Question 2

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.

Answer 2

D

Question 3

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.

Answer 3

D

Question 4

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 5

The genotype for a pea plant that is homozygous recessive for both height and pea color would be:

A) tt.
B) YY.
C) TtYy.
D) ttyy.
E) TTYY.

Question 6

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 7

Which of the following represents the possible genotype(s) resulting from a cross between an individual heterozygous (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 8

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) one allele can mask the expression of a recessive allele in a hybrid.
D) its phenotype is always expressed in all generations.
E) its phenotype is more beneficial than the recessive phenotype.

Question 9

Which of the following represents the possible genotype(s) resulting from a cross between two individuals that are heterozygous (Bb)?

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

Question 10

The physical location of a particular gene on a chromosome is called:

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

Question 11

Mendel verified true-breeding pea plants for certain traits before undertaking his experiments. The term "true-breeding" refers to:

A) genetically pure lines.
B) organisms that have a high rate of reproduction.
C) organisms that will produce identical copies of themselves upon reproduction.
D) organisms that are heterozygous for a given trait.
E) organisms that are homozygous for all possible traits.

Question 12

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.

Question 13

In peas, Mendel found that tall plants and yellow peas are dominant. The phenotype for a pea plant with the genotype TTyy would be:

A) intermediate height with greenish-yellow peas.
B) short with green peas.
C) short with yellow peas.
D) tall with green peas.
E) tall with yellow peas.

Question 14

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 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

____ 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 17

Which of the following represents the possible genotype(s) resulting from a cross between an individual homozygous for black hair (BB) and an individual homozygous for blonde hair (bb)?

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

Question 18

A diploid individual has a maximum of ____ different alleles for a particular locus.

A) one
B) two
C) three
D) four
E) more than four

Question 19

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 20

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.

Question 21

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

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

Question 22

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 23

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 24

A brown-eyed couple already has a child with blue eyes. What is the probability that their next child will have blue eyes, assuming that the brown eye allele is dominant and the blue eye allele is recessive?

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

Question 25

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 26

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 27

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 28

In humans, assume that the allele for brown eyes is dominant and the allele for blue eyes is recessive. If two brown-eyed individuals have a child with blue eyes, that means:

A) both parents are homozygous for brown eyes.
B) both parents are heterozygous for eye color.
C) there is a 1/4 chance that their second child will have brown eyes.
D) there is a 1/2 chance that their second child will have blue eyes.
E) there is a 3/4 chance that their second child will have blue eyes

Question 29

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 30

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 31

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 normal child for their fourth. What are the chances that the fourth child will be a normal male?

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

Question 32

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 33

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?

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

Question 34

A heterozygous fruit fly with normal wings and a gray body (VvBb) is crossed with homozygous flies with vestigial wings and black bodies (vvbb). If there are 800 F₁ progeny, the expected phenotypes would be:

A) 200 normal gray, 200 normal black, 200 vestigial gray, and 200 vestigial black
B) 400 normal gray and 400 vestigial black
C) 800 normal gray
D) 800 vestigial black
E) 450 normal gray, 150 normal black, 150 vestigial gray, and 50 vestigial black

Question 35

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 carriers
B) 3 homozygous normal : 1 carrier
C) 1 homozygous normal : 1 carrier
D) 1 hemophilia: 2 homozygous; normal : 1 carrier
E) all hemophiliacs

Question 36

Mendel's principle of independent assortment is explained by which metaphase I event?

A) separation of homologous chromosomes
B) crossing-over
C) synapsis
D) cytokinesis
E) random orientation of homologous chromosomes on the metaphase plate

Question 37

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 normal
B) 3 normal : 1 hemophilia
C) 1 hemophilia : 1 normal
D) 1 hemophilia : 3 normal
E) all hemophiliacs

Question 38

A brown-eyed couple heterozygous for eye color are planning on having two children. What is the probability that both children will have blue eyes, assuming brown eyes is dominant and blue eyes is recessive?

A) 0
B) 1/32
C) 1/16
D) 1/4
E) 1/2

Question 39

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 40

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

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

Question 41

A lizard with a striped tail and a normal head crossed with one having a normal tail and a spotted head produce all normal (no stripes or spots) F₁ progeny. What progeny would be expected to be produced by mating either of the parental lizards with another that had a striped tail and spotted head, if the genes conferring stripes and spots were close together on the same chromosome?

A) equal numbers of normal, striped, spotted and striped, and spotted
B) 3 striped : 1 spotted
C) mostly progeny that are striped or spotted
D) mostly progeny that are normal or striped and spotted
E) 9 normal : 3 striped : 3 spotted : 1 striped and spotted

Question 42

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 43

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 44

A particular 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 45

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 46

Compare and contrast the following pairs of related terms: gene and allele, genotype and phenotype, homozygous and heterozygous.

Question 47

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 48

What is dosage compensation with respect to the sex chromosomes, and how is this accomplished in humans?

Question 49

What are the possible phenotypes of the children if the mother's genotype is I^Ai for blood type and the father is I^Bi ? (Use the Punnett square to verify your answer.)

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

Question 50

____ 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 51

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 52

Linked genes are located on ____ chromosomes and do not follow the principle of ____.

A) different; independent assortment.
B) different; segregation
C) the same; segregation
D) the same; independent assortment
E) sex chromosomes; segregation

Question 53

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 54

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 55

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 56

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 57

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 58

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 59

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 60

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

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

Question 61

Pairs of homologous chromosomes are sorted randomly during prophase of meiosis.

Question 62

The mating of totally unrelated homozygous strains of corn produced a new strain of corn that was very different from both parental strains in many characteristics. Provide some explanations for this phenomenon.

Question 63

Dosage compensation is defined as the genetic phenomenon that allows two copies of an X-linked gene present in females to create the equivalent phenotype as in a male with only one copy of an X-linked gene.

Question 64

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

Question 65

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

Question 67

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

Question 69

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 70

A female black cat mated with an albino male and gave birth to 6 black kittens. When the albino male was mated with a different female black cat, 3 black cats and 2 albino cats were produced. How can you explain this genetic situation? Write genotypes for all three parental cats and offspring.

Question 71

Genotype can always be inferred from phenotype.
__________________

Question 72

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

Question 73

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

Question 74

What is an X-linked inheritance pattern? Use a specific example to explain the role of the father and mother in this unique inheritance pattern and note the differential impact on male and female offspring.

Question 75

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.
__________________

Question 76

In a Punnett square, the alleles available for inheritance from one parent are listed across the top and those from the other parent are listed across the left side.
__________________

Question 77

A test cross is performed to determine phenotype . __________________

Question 78

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