Deck 4: The Chromosome Theory of Inheritance

Question 1

If you are a male, your X chromosome contains genes derived from

A)your paternal grandfather only.
B)your maternal grandfather only.
C)both your paternal and maternal grandfathers.
D)both your paternal grandfather and grandmother.
E)both your maternal grandfather and grandmother.

Answer 1

both your maternal grandfather and grandmother.

Question 2

If a geneticist were to closely examine the make-up of a single autosomal chromosome from one of your cells, that chromosome would be found to be

A)derived entirely from genes from just one of your grandparents.
B)a mosaic of genes derived from your mother and father.
C)a mosaic of genes derived from all four of your grandparents.
D)a mosaic of genes derived from just two of your grandparents-either your two grandfathers or your two grandmothers.
E)a mosaic of genes derived from just two of your grandparents-either your maternal grandparents or your paternal grandparents.

Answer 2

a mosaic of genes derived from just two of your grandparents-either your maternal grandparents or your paternal grandparents.

Question 3

Which of the following statements applies to homologous chromatids?

A)They are attached to the same centromere.
B)They are genetically identical.
C)They segregate from each other at anaphase of mitosis.
D)They contain the same genes in the same order but may have different alleles of some genes.
E)More than one statement applies to homologous chromatids.

Answer 3

They contain the same genes in the same order but may have different alleles of some genes.

Question 4

A chromosome with two arms of equal length is referred to as

A)acrocentric.
B)homologous.
C)telocentric.
D)metazoan.
E)metacentric.

Question 5

At which of the following stages of meiosis would homologous chromosomes be paired?

A)prophase of meiosis I
B)prophase of meiosis II
C)metaphase of meiosis I
D)metaphase of meiosis II
E)both prophase of meiosis I and metaphase of meiosis I.

Question 6

The stage of mitosis when chromosomes condense to form rod-shaped structures visible under the microscope is called

A)interphase.
B)prophase.
C)metaphase.
D)anaphase.
E)telophase.

Question 7

Crossing over between homologous chromosomes occurs at which of the following stages of meiosis?

A)S phase
B)prophase I
C)metaphase I
D)anaphase I
E)prophase II

Question 8

The mitotic stage during which chromosomes begin attaching to spindle fibers and moving randomly and reversibly to the centrosomes is

A)prophase.
B)prometaphase.
C)metaphase.
D)anaphase.
E)telophase.

Question 9

During which of the following stages of the cell cycle would a chromosome consist of only a single chromatid?

A)G₁
B)G₂
C)mitotic prophase
D)mitotic metaphase
E)All the choices are correct.

Question 10

Premeiotic germ cells that divide mitotically in females are referred to as

A)primary oocytes.
B)secondary oocytes.
C)ootids.
D)oogonia.
E)ova.

Question 11

The stage of mitosis when sister chromatids separate from each other and migrate to opposite poles of a cell is called

A)interphase.
B)prophase.
C)metaphase.
D)anaphase.
E)telophase.

Question 12

Nondisjunction can occur at either the first or second division of meiosis.XYY individuals would most likely arise from nondisjunction at the ______ meiotic division in the ______.

A)first, mother
B)second, mother
C)first, father
D)second, father
E)More than one of the choices could give rise to XYY individuals.

Question 13

In Drosophila virilis, nuclei of somatic cells contain 12 chromosomes while nuclei of sperm cells contain only 6 chromosomes.What does "n" equal for this species?

A)3
B)6
C)12
D)24
E)6 or 12, depending on cell type

Question 14

Which type of chromosome provides the basis for sex determination in many sexually reproducing organisms?

A)haploid
B)diploid
C)autosomes
D)sex chromosomes
E)homologous chromosomes

Question 15

Humans have 22 pairs of autosomes plus one sex chromosome pair.How many autosomes are present in a normal human primary spermatocyte?

A)22
B)23
C)44
D)45
E)46

Question 16

The chromosomal structure to which spindle fibers attach during the mitotic divisions is referred to as a

A)chromatid.
B)centrosome.
C)kinetochore.
D)metaphase plate.
E)centromere.

Question 17

Which of the following events occurs during mitosis but not during meiosis?

A)segregation of sister chromatids
B)pairing of homologous chromosomes
C)crossing-over between homologous chromosomes
D)alignment of chromosomes on the metaphase plate
E)None of the choices is correct

Question 18

The cells in which meiosis occurs in males are referred to as

A)spermatocytes.
B)spermatogonia.
C)spermatids.
D)oocytes.
E)sperm.

Question 19

Drosophila melanogaster has four pairs of chromosomes.Sperm from this species are formed by a meiotic process in which homologous chromosomes pair and segregate but do not undergo crossing over.How many genetically different kinds of sperm could be produced by a Drosophila melanogaster male?

A)4
B)8
C)16
D)64
E)256

Question 20

Nondisjunction can occur at either the first or second division of meiosis.XXY individuals could arise from nondisjunction at the ______ meiotic division in the ______.

A)first, mother
B)second, mother
C)first, father
D)second, father
E)More than one of the choices could give rise to XXY individuals.

Question 21

Hemophilia is caused by an X-linked recessive mutation in humans.If a woman whose paternal uncle (father's brother) was a hemophiliac marries a man whose brother is also a hemophiliac, what is the probability of their first child having hemophilia (Note: assume that there are no other cases of hemophilia in the pedigree and no hidden carriers)?

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

Question 22

A white-eyed female fruit fly is mated to a red-eyed male.One of their progeny is a white-eyed female.This white-eyed daughter likely arose from nondisjunction of the sex chromosomes during _________ in the __________.

A)meiosis I, mother
B)meiosis II, mother
C)meiosis I, father
D)meiosis II, father
E)meiosis I or II, mother

Question 23

Which aspect(s) of chromosome behavior is/are primarily responsible for the tremendous amount of genetic variability associated with sexual reproduction?

A)Segregation of sister chromatids at anaphase II of meiosis
B)Segregation of homologous chromosomes at anaphase I of meiosis
C)Crossing over between homologous chromosomes during prophase I of meiosis
D)Independent alignment of different homologous pairs on the metaphase I spindle
E)Both crossing over between homologous chromosomes during prophase I of meiosis and independent alignment of different homologous pairs on the metaphase I spindle contribute to genetic variability

Question 24

Suppose you discover a new species of worm that exists in two forms-slimy and non-slimy.You find that mating slimy females to non-slimy males produces offspring consisting of slimy males and non-slimy females, whereas mating non-slimy females with slimy males produces offspring of both sexes that are all slimy.You would conclude that the _________ allele is dominant and that ________ are the heterogametic sex (the sex with two different sex chromosomes) in this species of worm.

A)slimy, females
B)slimy, males
C)non-slimy, females
D)non-slimy, males

Question 25

What aspect of chromosome behavior most clearly accounts for Mendel's law of independent assortment?

A)Movement of sister chromatids to opposite poles at anaphase II of meiosis
B)Movement of homologous chromosomes to opposite poles at anaphase I of meiosis
C)Crossing over between homologous chromosomes during prophase I of meiosis
D)Replication of chromosomes prior to meiosis
E)Independent alignment of different homologous pairs on the metaphase I spindle

Question 26

What aspect of chromosome behavior most clearly accounts for Mendel's law of segregation?

A)Movement of sister chromatids to opposite poles at anaphase II of meiosis
B)Movement of homologous chromosomes to opposite poles at anaphase I of meiosis
C)Crossing over between homologous chromosomes during prophase I of meiosis
D)Replication of chromosomes prior to meiosis
E)Independent alignment of different homologous pairs on the metaphase I spindle

Question 27

Mitosis results in _______ chromosome number, whereas meiosis results in _______ chromosome number.

A)a doubling of, no change in
B)no change in, no change in
C)a reduction by half in, no change in
D)no change in, a doubling of
E)no change in, a reduction by half in

Question 28

Males with one copy of an X-linked gene are said to be _________ for that gene.

A)homozygous
B)heteroallelic
C)heterozygous
D)hemizygous
E)deficient

Question 29

Cells said to be in the G₀ stage

A)have two chromatids per chromosome.
B)are replicating their chromosomes.
C)are about to enter the mitotic phase of the cell cycle.
D)are in an extended G₁ phase and no longer cycling.
E)are dead.

Question 30

Which of the following is not a property of homologous chromosomes?

A)They pair physically during prophase of meiosis I.
B)They exchange genes by crossing over during meiosis.
C)They carry alleles for the same genes at the same chromosomal position.
D)They are attached to the same centromere during G₂ of the cell cycle.
E)They segregate to opposite poles at anaphase of meiosis I.

Question 31

A white-eyed female fruit fly is mated to a red-eyed male.One of their progeny is a white-eyed female.What is the likely karyotype of this white-eyed daughter?

A)XX
B)XXY
C)XO
D)XXX
E)XYY

Question 32

In chickens, it is the females that have two different sex chromosomes (Z and W) while the males have two Z chromosomes.A Z-linked gene controls the pattern of the feathers, with the dominant B allele causing the barred pattern and the b allele causing non-barred feathers.From which of the following crosses would all of the daughters be of one type (barred or non-barred) and all of the sons the other type?

A)barred females * non-barred males
B)non-barred females * barred males
C)non-barred females * non-barred males
D)barred females * barred males
E)More than one of the choices is correct.

Question 33

In fruit flies, brown eyes can be caused by the recessive mutations pn (prune), bw (brown) or ry (rosy), which are on the X chromosome, second chromosome, and third chromosome, respectively.Wild-type alleles for all three genes must be present for eyes to be red.Suppose that two brown-eyed flies are crossed and their progeny consist of brown-eyed sons and red-eyed daughters.Which mutation is responsible for the brown eyes in the parental female?

A)pn
B)bw
C)ry
D)either bw or ry
E)any of the three - pn, bw, or ry

Question 34

A variable feature of some chromosomes in corn is the presence or absence of knobs at particular sites.Suppose that one member of each of two pairs of chromosomes in a corn plant has a knob.If this plant is crossed with a knobless plant, what percentage of the offspring is expected to be knobless?

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

Question 35

Suppose you discover a new variant in which mice have spiky fur instead of the usual soft fur.You notice that this trait seems only to be present in males.To investigate this pattern, you cross a spiky-fur male with a soft-fur female, and find that all of the F₁ progeny of both sexes have soft fur.You then interbreed the F₁ and observe that all of the F₂ females have soft fur, but 1/4 of the F₂ males have spiky fur.You conclude that the spiky allele is

A)an X-linked recessive.
B)Y-linked.
C)autosomal recessive with sex-limited expression.
D)an X-linked dominant.
E)an autosomal dominant with sex-limited expression.

Question 36

Cells in the G₂ stage of the cell cycle have ______ as cells of the same species in the G₁ stage.

A)twice as many chromosomes
B)twice as many chromatids
C)half as many chromatids
D)the same number of chromatids
E)half as many chromosomes

Question 37

Color vision depends upon the dominant alleles of three genes: the R gene and the G gene are both on the X chromosome, while the B gene is autosomal.Recessive mutations in any of the three genes can cause color blindness.Suppose a colorblind man marries a colorblind woman and all of their offspring have normal vision.What is the genotype of the woman?

A)RRGGbb
B)RRggBB
C)rrGGbb
D)RRggBB or RRGGbb
E)rrGGbb or rrggBB

Question 38

Red green color blindness is controlled by an X chromosomal gene in humans.A normal man and normal woman whose fathers are both color blind marry.What is the probability that their first child will be color blind?

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

Question 39

A cross between a white-eyed female fruit fly and a red-eyed male would generate which of the following types of progeny?

A)red-eyed females and white-eyed males
B)white-eyed females and red-eyed males
C)all red-eyed females and a 50:50 mixture of white-eyed and red-eyed males
D)all red-eyed males and a 50:50 mixture of white-eyed and red-eyed females
E)The result cannot be predicted because it depends on whether the female is homozygous or heterozygous

Question 40

Microtubules that attach to centrosomes but not chromosomes and that interdigitate with microtubules emanating from the centrosome at the opposite pole are known as

A)kinetochore microtubules.
B)polar microtubules.
C)astral microtubules.
D)interdigitating microtubules.
E)None of the choices is correct.

Question 41

You examine cells with a microscope and detect that there are two Barr bodies present in each cell.What is the most likely genotype of the cells?

A)XX
B)XY
C)XO
D)XXY
E)XXX

Question 42

In animal gametogenesis, a single primary spermatocyte generates ______ sperm, while a single primary oocyte generates ______ egg(s).

A)1, 4
B)1, 1
C)4, 2
D)4, 1
E)4, 4

Question 43

Individuals with an XXY karyotype are ______ in humans and ______ in fruit flies.

A)male, male
B)male, female
C)female, male
D)female, female
E)male, intersexual

Question 44

Which sex chromosomes are limited to only one sex?

A)X and Z
B)X and W
C)Y and Z
D)Y and W
E)X and Y

Question 45

In humans, XO individuals are females with Turner syndrome and XXY individuals are males with Klinefelter syndrome.Red green color blindness is caused by an X-linked recessive allele.Suppose a colorblind man and a normal woman with no family history of color blindness married and had a daughter who was colorblind and had Turner syndrome.Which event could have given rise to this offspring?

A)nondisjunction at meiosis I in the mother
B)nondisjunction at meiosis II in the mother
C)nondisjunction at meiosis I in the father
D)nondisjunction at meiosis II in the father
E)nondisjunction at either meiosis I or meiosis II in the mother

Question 46

The following is a list of mitotic events in no particular order.A Chromosomes align on the midplate of the cell.B Kinetochores begin attaching to spindle fibers.C Nuclear membrane reforms and chromosomes decondense.D Chromosomes condense and centrosomes migrate to opposite sides of nucleus.E Sister chromatids separate and move to opposite poles.What is the correct order of events?

A)BDACE
B)DABEC
C)DBAEC
D)ABDCE
E)EDBAC

Question 47

In fruit flies, an X-linked dominant mutation (N) causes Notch wings in heterozygous females but is lethal in hemizygous or homozygous condition.What ratio of offspring would be observed in a cross of a Notch female with a normal male?

A)1/3 Notch females, 1/3 normal females, 1/3 normal males
B)1/4 Notch females, 1/4 normal females, 1/4 Notch males, 1/4 normal males
C)1/2 Notch females, 1/2 normal males
D)1/2 normal females, 1/2 Notch males
E)2/3 Notch females, 1/3 normal males

Question 48

Here is a list of meiotic events in no particular order.A Segregation of homologous chromosomes to opposite poles.B Segregation of sister chromatids to opposite poles.C Alignment of homologous pairs on the midplate of the cell.D Pairing and synapsis of homologous chromosomes.E Condensation of chromosomes in a diploid nucleus.What is the correct order of events?

A)CDEAB
B)DCEBA
C)EDCBA
D)EDCAB
E)DCABE

Question 49

In humans, XO individuals are females with Turner's syndrome and XXY individuals are males with Klinefelter syndrome.Which of the following events may not give rise to a Klinefelter male?

A)nondisjunction at meiosis I in the mother
B)nondisjunction at meiosis II in the mother
C)nondisjunction at meiosis I in the father
D)nondisjunction at meiosis II in the father
E)All of the choices could give rise to a Klinefelter male.

Question 50

An XY individual carries mutations in both the SRY and AR genes.Which anatomic sex is this individual expected to be?

A)Female
B)Male

Question 51

A cell with three pairs of chromosomes has the genotype AaBbCc, such that each pair of alleles is on a different pair of chromosomes.If this cell were to undergo meiotic division, how many genetically different types of gametes could be produced?

A)1
B)3
C)6
D)8
E)9

Question 52

In the following pedigree, the indicated trait is caused by which type of allele?

A)autosomal recessive
B)autosomal dominant
C)X-linked recessive
D)X-linked dominant
E)Y-linked

Question 53

In human oogenesis, how many chromosomes does a primary oocyte carry?

A)22
B)23
C)44
D)46
E)96

Question 54

In the following pedigree, the indicated trait is caused by which type of allele?

A)autosomal recessive
B)autosomal dominant
C)X-linked recessive
D)X-linked dominant
E)Y-linked

Question 55

In the following pedigree, the indicated trait is caused by which type of allele?

A)autosomal recessive
B)autosomal dominant
C)X-linked recessive
D)X-linked dominant
E)Y-linked

Question 56

You engineer a chromosomally XY mouse in which the SRY gene is inactivated.What do you expect to observe in this mouse?

A)The mouse will develop male anatomic features.
B)The mouse will develop female anatomic features.
C)The mouse's Y chromosome will convert into an X chromosome.
D)The mouse's X chromosome will convert into a Y chromosome.
E)The mouse will exhibit an additional X chromosome (making it XXY).

Question 57

In the following pedigree, the indicated trait is caused by which type of allele?

A)autosomal recessive
B)autosomal dominant
C)X-linked recessive
D)X-linked dominant
E)Y-linked

Question 58

In which of the following cases will a Barr body be seen?

A)only XX
B)XY
C)XO
D)only XXY
E)both XX and XXY

Question 59

In the following pedigree, the indicated trait is caused by what type of allele?

A)autosomal recessive
B)autosomal dominant
C)X-linked recessive
D)X-linked dominant
E)Y-linked

Question 60

A cell with three pairs of chromosomes has the genotype AaBbCc, such that each pair of alleles is on a different pair of chromosomes.If this cell were to undergo mitotic division, how many genetically different types of gametes could be produced?

A)1
B)3
C)6
D)8
E)9

Question 61

Suppose you discovered a new mutation in mice that causes a curved spine.You noticed that this mutation is seen only in females.When curved-spine females are crossed with normal males, the progeny are always recovered in the ratio: 1/3 curved-spine females, 1/3 normal females, 1/3 normal males.Explain the genetic basis for this ratio.

A)Lethal autosomal allele
B)Lethal sex-linked allele
C)Recessive sex-linked allele
D)Recessive autosomal allele
E)Dominant sex-linked allele

Question 62

Individuals with Turner syndrome have which of the following sex chromosome complements?

A)XO
B)XX
C)XYY
D)XXY
E)XXX

Question 63

Which of the following statements is FALSE?

A)Sister chromatids of the same chromosome are identical.
B)Sister chromatids can be on nonhomologous chromosomes.
C)Homologous chromosomes are not necessarily identical.
D)An example of a nonhomologous chromosome pair is paternal chromosome 1 and paternal chromosome 2 in a human.

Question 64

Which of the following is the diploid cell destined for a specialized role in the production of gametes?

A)Somatic cell
B)Germ cell
C)Spermatid
D)Polar body
E)Ootid

Question 65

Which of the following are the structures that appear along the synaptonemal complex during pachytene and are where parts between nonsister chromatids are exchanged?

A)Chiasmosomes
B)Telomeres
C)Centromeres
D)Recombination nodules

Question 66

In human oogenesis, how many chromosomes does a secondary oocyte carry?

A)22
B)23
C)44
D)46
E)96

Question 67

At which phase of the cell cycle are sister chromatids generated?

A)G₀
B)G₁
C)G₂
D)S
E)M

Question 68

In human oogenesis, how many chromosomes does an oogonium carry?

A)22
B)23
C)44
D)46
E)96

Question 69

Which term describes chromosomes where the centromere is located closer to one end of the chromosome?

A)Metacentric
B)Acrocentric
C)Holocentric
D)Anacentric

Question 70

In human oogenesis, how many chromosomes does an ovum carry?

A)22
B)23
C)44
D)46
E)96