Deck 8: Chromosome Mutations: Variation in Number and Arrangement

Question 1

Having a complete set or sets of chromosomes is called____.

A)ploidy
B)diploid
C)euploid
D)monoploid
E)aneuploidy

Answer 1

euploid

Question 2

Noninvasive prenatal genetic diagnosis is sometimes preferred to amniocentesis because ____

A)the mother does not have to be present
B)it requires only a blood draw from the mother
C)it requires less technical time of a research lab
D)it gives more precise results
E)it gives quicker results

Answer 2

it requires only a blood draw from the mother

Question 3

Given that a human normally contains 46 chromosomes,give the chromosome number for each of the following conditions: Triploid Trisomy 13

A)69,47
B)138,47
C)69,45
D)138,45
E)96,47

Answer 3

A

Question 4

What is the outcome of nondisjunction in meiosis I?

A)a resultant gamete that is triploid
B)a resultant gamete that may harbor from one chromosome both homologs from one parent or none at all
C)a resultant gamete that is devoid of all chromosomes
D)a resultant gamete that may harbor from one chromosome both sister chromatids or none at all
E)four gametes that are all trisomic

Question 5

Trisomy 21,or Down syndrome,occurs when there is a normal diploid chromosomal complement but one extra)chromosome 21.Although fertility is reduced in both sexes,females have higher fertility rates than males.Van Dyke et al.1995; Down Syndrome Research and Practice 32 : 65-69 summarize data involving children born of Down syndrome individuals.Assume that children are born to a female with Down syndrome and a normal 46- chromosome male.What proportion of the offspring would be expected to have Down syndrome?

A)None of the offspring would be expected to have Down syndrome.
B)One- half of the offspring would be expected to have Down syndrome.
C)One- third of the offspring would be expected to have Down syndrome.
D)Two- thirds of the offspring would be expected to have Down syndrome.
E)All the children would be expected to have Down syndrome.

Question 6

What experiment led to the identification of the DSCR Down Syndrome Critical Region ?

A)an extra DSCR was injected into yeast cells
B)transgenic humans were developed that had a duplicated DSCR
C)a mouse model was developed lacking the DSCR
D)cancer cells were sequenced to identify the VEGF gene
E)a mouse model was developed trisomic for the DSCR

Question 7

____is viewed as a major cause of aneuploidy.

A)X- ray mutations
B)Heat treatment
C)Segmental deletions
D)Colchicine treatment
E)Nondisjunction

Question 8

Name two methods used in genetic prenatal diagnostic testing in humans.

A)chorionic villus sampling and cellular mitotic analysis
B)whole genome sequencing and PCR
C)amniocentesis and DSCR
D)amniocentesis and NIPGD
E)amniocentesis and fetal uterine physiology compatibility test

Question 9

An expected meiotic pairing configuration in a____ would be a trivalent.

A)monoploid
B)diploid
C)monosomic individual
D)trisomic individual
E)triploid

Question 10

The condition that exists when an organism gains or loses one or more chromosomes but not a complete haploid set is known as____ .

A)polyploidy
B)triploidy
C)euploidy
D)aneuploidy
E)trisomy

Question 11

What explanation is generally given for lethality of monosomic individuals?

A)The loss of a single chromosome is not generally lethal,unless the individual is inbred.
B)Cells count the number of chromosomes they have and will undergo apoptosis when the chromosome number is incorrect.
C)Monosomic chromosomes cannot undergo mitosis correctly.
D)The gametes of monosomic individuals cannot undergo meiosis,and this is lethal.
E)Monosomy may unmask recessive lethals that are tolerated in heterozygotes carrying the wild- type allele.

Question 12

Trisomy 21,or Down syndrome,occurs when there is a normal diploid chromosomal complement but one extra)chromosome 21.While there is reduced fertility in both sexes,females have higher fertility than males.Van Dyke et al.1995; Down Syndrome Research and Practice 32 : 65- 69 summarize data involving children born of Down syndrome individuals.Given the fact that conceptuses with 48 chromosomes four #21 chromosomes are not likely to survive early development,what percentage of surviving offspring would be expected to have Down syndrome if both parents have Down syndrome?

A)One- half of the surviving offspring would be expected to have Down syndrome.
B)Two- thirds of the surviving offspring would be expected to have Down syndrome.
C)None of the surviving offspring would be expected to have Down syndrome.
D)One- third of the surviving offspring would be expected to have Down syndrome.
E)All the children would be expected to have Down syndrome.

Question 13

A child is born with Turner's syndrome and she is red green color blind recessive X- linked).Her father is red green color blind as well and her mother is homozygous dominant for color sight.What had to happen in order for this child to be born with this chromosomal complement?

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

Question 14

A son is born with Kleinfelter's syndrome and hemophilia.His father was normal and his mother was a carrier for the recessive X- linked blood clotting disorder.What occurred in meiosis to produce this genetic outcome?

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

Question 15

Assume that a species has a diploid chromosome number of 24.The term applied to an individual with 25 chromosomes would be____ .

A)triploid
B)trisomy
C)euploid
D)aneuploidy
E)aneuploidy and trisomy

Question 16

What is the leading cause of Down syndrome?

A)In men over 25,sperm formation is impaired and produces monosomic children.
B)Aberrant implantation in the uterus leads to developmental problems in the fetus.
C)The nondisjunctional event that produces Down syndrome occurs more frequently during oogenesis in women older than age 35.
D)In older parents,there is egg/sperm incompatibility leading to duplication of chromosome 21.
E)In older females,chromosome 21 is duplicated leading to abnormal egg formation.

Question 17

Name the polyploid condition that is formed from the addition of an extra set of chromosomes identical to the normal diploid complement of the same species.

A)autotetraploidy,assuming the normal chromosome complement is haploid
B)allotetraploidy,assuming the normal chromosome complement is diploid
C)alloeuploidy,assuming the normal chromosome complement is diploid
D)autotetraploidy,assuming the normal chromosome complement is diploid
E)autooctoploidyploidy,assuming the normal chromosome complement is haploid

Question 18

An individual with Patau syndrome would be____ .

A)said to have a trisomy
B)termed a triploid
C)said to have a monosomy
D)termed a haploid
E)termed a euploid

Question 19

Haploinsufficiency refers to____ .

A)the genetic predisposition for some genes to come in only one copy in the genome
B)the process by which a single gene will cause a cascading effect on a genome's phenotype
C)the condition whereby a single cell is insufficient to divide to cause cancer
D)the condition whereby a single chromosome is insufficient to sustain life
E)a state of being whereby a single gene is sufficient to cause several phenotypes

Question 20

Given that a human normally contains 46 chromosomes,give the chromosome number for each of the following conditions: Turner syndrome female,no Barr bodies Klinefelter syndrome male,one Barr body

A)47,45
B)46,47
C)45,47
D)47,47
E)45,46

Question 21

An ____may arise when three sperm cells are involved in fertilization of a single egg.

A)allotriploid
B)allotetraploid
C)autotriploid
D)aneuploidy
E)autotetraploid

Question 22

What error of meiosis leads to both a duplication and a deletion?

A)replication cross formation
B)replication errors
C)X- ray chromosomal breakage
D)D loop formation
E)unequal crossing over

Question 23

Gene amplification is the basis for____ .

A)formation of the translocation cross
B)the nucleolar organizing region
C)bar- eyed flies
D)interstitial deletions
E)a segmental deletion

Question 24

Inversion heterokaryotypes are often characterized as having reduced crossing over and reduced fertility.Assume that you were examining a strain of organisms you knew to be inversion heterokaryotypes and saw a relatively high number of double chromatid bridges extending between anaphase I nuclei,as indicated in the following drawing.What is the product of this type of inversion loop?

A)two acentric fragments and two dicentric chromosomes
B)two chromosomes with deletions and two acentric fragments
C)one acentric fragment,one dicentric chromosome,and two wild- type chromosomes
D)two chromosomes with deletions and two with duplications
E)four wild- type chromosomes

Question 25

Which of the following is not a potential outcome of a gene duplication?

A)they may lead to translocation cross formation during synapsis
B)they may result in gene redundancy
C)they may result in providing the raw material for evolution
D)they may produce phenotypic variation
E)they may lead to the development of gene families

Question 26

A ____ inversion is one whose breakpoints do not flank the centromere.

A)acentric
B)dicentric
C)pericentric
D)segmental
E)paracentric

Question 27

What is formed when meiosis occurs in an individual who is heterozygous for an intercalary deletion?

A)a trifecta chromosomal cross
B)a terminal loop
C)a compensation loop
D)a translocation
E)a translocation cross

Question 28

Which of the following is an example of an endopolyploid?

A)an egg has complete nondisjunction and the resultant offspring is triploid
B)cells lining the gut of mosquito larvae attain 16n ploidy
C)one chromosome is lost during cell division
D)two diploid mate and produce a tetraploid
E)an individual suffers from a trisomy

Question 29

Describe double Bar mutations in Drosophila melanogaster.

A)large deletion in the X chromosome
B)a female fly with only one X chromosome
C)an X chromosome with two duplications of the 16A region
D)duplications in a portion of the X chromosome
E)an inversion heterozygote of the X chromosome

Question 30

The chromosomal aberration that causes cri- du- chat syndrome can be referred to as an____.

A)segmental deletion
B)reciprocal translocation
C)simple translocation
D)duplication
E)inversion

Question 31

Assume that a species has a diploid chromosome number of 24.The term applied to an individual with 36 chromosomes would be____ .

A)triploid
B)allopolyploid
C)aneuploidy
D)monoploid
E)tetraploid

Question 32

How do deletions and translocations in chromosomes often occur?

A)chromosomes will break and the sticky ends will rejoin
B)during meiosis I,sister chromatid exchange leads to abnormalities
C)colchicine treatment causes chromosomal rearrangements
D)when cells undergo meiosis II,chromosomes naturally break when sister chromatids are being pulled apart
E)chromosomes will fuse telomere to telomere

Question 33

Doubling the chromosomes of a sterile species hybrid with colchicine or cold shock is a method used to produce a fertile species hybrid called a ____.

A)autoploid
B)allopolyploid
C)amphidiploid
D)triploid
E)autoallopolyploid

Question 34

Assume that an organism has a haploid chromosome number of 7.There would be ____chromosomes in a monoploid individual of that species.

A)3.5
B)7
C)14
D)28
E)42

Question 35

What is NOT a potential consequence of a copy number variation?

A)phenotypic consequences that track with the number of each gene
B)none
C)higher protein levels of specific genes
D)phenotypic consequences leading to enhanced ability to fight infection
E)loss of function at multiple loci

Question 36

Provide an example of gene redundancy that occurs in both eukaryotes and prokaryotes.

A)CNV
B)spindle fiber protein genes
C)rDNA
D)cell wall proteins
E)centromeres

Question 37

The condition known as cri- du- chat syndrome in humans has a genetic constitution designated as ____.

A)trisomy
B)46,5p-
C)45,X
D)heteroplasmy
E)triploidy

Question 38

Colchicine is an alkaloid derived from plants.What is its effect on chromosome behavior?

A)By blocking DNA replication,chromosomes fail to migrate to the poles at anaphase; thus,homologous chromosomes end up in the same nucleus.
B)By blocking DNA replication,chromosomes do not undergo meiosis II and instead half the gametes are empty.
C)By blocking DNA replication,chromosomes do not undergo meiosis I and instead all gametes suffer from aneuploidy.
D)By interfering with spindle formation,replicated chromosomes fail to migrate to the poles at anaphase; thus,sister chromatids end up in the same nucleus.
E)By interfering with spindle formation,replicated chromosomes fail to migrate to the poles at anaphase; thus,homologous chromosomes end up in the same nucleus.

Question 39

A chromosome without a centromere is ____.

A)segmental
B)paracentric
C)pericentric
D)dicentric
E)acentric

Question 40

Assume that an organism has a diploid chromosome number of 14.There would be ____chromosomes in a tetraploid.

A)104
B)42
C)56
D)14
E)28

Question 41

Genetic anticipation is best described as____ .

A)the phenomenon by which synapsis is delayed due to translocation cross formation
B)trinucleotide repeats increase in future generations
C)cells stop during the cell cycle to check for DNA damage or acentric fragments
D)trinucleotide repeats form fragile sites
E)the G2 gap before meiosis

Question 42

Although the most frequent forms of Down syndrome are caused by a random error,nondisjunction of chromosome 21,Down syndrome occasionally runs in families.The cause of this form of familial Down syndrome is ____.

A)a maternal age effect
B)a chromosomal aberration involving chromosome 1
C)an inversion involving chromosome 21
D)a translocation between chromosome 21 and a member of the D chromosome group
E)too many X chromosomes

Question 43

A genomic condition that may be responsible for some forms of fragile X syndrome,as well as Huntington disease,involves____ .

A)various lengths of trinucleotide repeats
B)multiple inversions in the X chromosome
C)single translocations in the X chromosome
D)plasmids inserted into the FMR- 1 gene
E)multiple breakpoints fairly evenly dispersed along the X chromosome

Question 44

What type of chromosomal configuration does the following diagram illustrate?

A)inversion paracentric.heterozygote
B)reciprocal translocation heterozygote
C)inversion paricentric.heterozygote
D)inversion paracentric.homozygote
E)simple translocation heterozygote

Question 45

What is a fragile site?

A)a site in a chromosome prone to duplication,such as the bar gene
B)a structural component of a chromosome due to proteins bound to it that leads to a high percentage of chromosomal breakage
C)the telomere of a chromosome can fall off due to spindle malfunctions during meiosis
D)a structural component of a chromosome due to the nucleotide sequence to it that leads to a high percentage of chromosomal breakage
E)an area around the centromere prone to inversion due to gene duplications

Question 46

What is a potentially evolutionary advantage of inversion heterozygosity?

A)inversion loops stimulate favorable allele combinations
B)haploinsufficiency does not occur in inversion heterozygotes
C)if a favorable complement of alleles occurs in an inversion heterozygote,they will not be disrupted by crossing over
D)enhanced genetic variation in the offspring
E)there is none

Question 47

Recently,a gene located on chromosome 3 in humans,FHIT,has been shown to be associated with the significant human malady known as ____ .

A)XYY/XY mosaicism
B)Klinefelter syndrome
C)Huntington disease
D)cancer
E)"mad- cow" disease

Question 48

Which of the following statements is TRUE?

A)In general,inversion and translocation heterozygotes are as fertile as organisms whose chromosomes are in the standard arrangement.
B)Inversions and translocations are without evolutionary significance.
C)Translocations may be pericentric or paracentric.
D)Individuals with familial Down syndrome are trisomic and have 47 chromosomes.
E)Familial Down syndrome is caused by a translocation involving chromosome 21.