Deck 12: Chromosomal Rearrangements and Changes in Chromosome Number

Question 1

Karyotypes generally remain constant within a species because

A)rearrangements occur frequently.
B)changes in chromosome number occur infrequently.
C)genetic instabilities produced by genomic changes usually are at a selective disadvantage.
D)genetic imbalances are often at a selective advantage.

Answer 1

genetic instabilities produced by genomic changes usually are at a selective disadvantage.

Question 2

Which of the following does not happen when an intragenic inversion occurs?

A)One part of the gene is relocated to a distant region of the chromosome.
B)One part of the gene stays at its original site.
C)Homozygotes for the inversion do not survive.
D)The gene's function is not disrupted.

Answer 2

The gene's function is not disrupted.

Question 3

FISH analysis would least likely be used to detect

A)translocations.
B)duplications.
C)deletions.
D)point mutations.

Answer 3

point mutations.

Question 4

An inversion may result from

A)A 360⁰ rotation of a chromosomal region following two double-strand breaks in a chromosome's DNA.
B)A crossover between DNA sequences present in two positions on the same chromosome in inverted orientation.
C)A crossover between repetitive DNA sequences present in two positions on the same chromosome in the same orientation.
D)Crossing over between two repetitive sequences on different chromosomes

Question 5

Which of the following molecular techniques could a scientist use to help locate genes on cloned fragments of DNA with deletion mutants?

A)in situ hybridization and cross over analysis
B)crossover and Southern blot analysis
C)Southern blot , crossover analysis and in situ hybridization
D)in situ hybridization and Southern blot analysis

Question 6

For an organism to survive a deletion of more than a few genes, it must carry a nondeleted homolog of the deleted chromosome.This organism is known as

A)a deletion heterozygote.
B)a deletion homozygote.
C)dosage compensation.
D)a triplolethal chromosome.

Question 7

Despite selection against chromosomal variations

A)related species almost always have the same karyotype.
B)related species almost always have a different karyotype.
C)closely related species diverge by many chromosomal rearrangements.
D)distantly related species diverge by only a few chromosomal rearrangements.

Question 8

During the pairing of homologs in prophase of meiosis I, the region of a chromosome bearing extra copies of a particular chromosomal region that has nothing with which to recombine with forms a

A)inversion loop.
B)deletion heterozygote.
C)duplication loop.
D)deletion loop.

Question 9

The term for when a piece of one chromosome attaches to another chromosome is

A)inversion.
B)duplication.
C)deletion.
D)translocation.

Question 10

In general, which type of mutation usually has the greatest probability of lethality?

A)inversion
B)duplication
C)deletion
D)translocation

Question 11

What types of mutations adds material to the genome?

A)inversions
B)duplications
C)deletions
D)translocations

Question 12

During the pairing of homologs in prophase of meiosis I, the region of a normal, nondeleted chromosome that has nothing with which to recombine forms a

A)inversion loop.
B)deletion heterozygote.
C)crossover suppressor.
D)deletion loop.

Question 13

Duplications can be created by

A)chromosomal breakage and normal repair.
B)equal crossing over.
C)errors in replication.
D)single point mutations

Question 14

The term for the type of mutation that results in a loss of material from the genome is

A)inversion
B)duplication
C)deletion
D)translocation

Question 15

The type of chromosomal rearrangement that reorganizes the DNA sequence within one chromosome is known as a(n)

A)inversion.
B)duplication.
C)deletion.
D)translocation.

Question 16

An acentric fragment can be the result of crossing over between a normal chromosome and a chromosome that has undergone what kind of mutation?

A)paracentric inversion
B)duplication
C)translocation
D)pericentric inversion

Question 17

Inversions may be difficult to detect because they

A)never visibly change chromosome banding patterns.
B)increase recombination in heterozygotes.
C)do not usually cause an abnormal phenotype.
D)normally are removed immediately in natural populations.

Question 18

An example in humans of a disease or syndrome that can occur at higher frequency when a deleted copy of a gene is inherited is

A)triplolethal.
B)scarlet eyes.
C)retinoblastoma.
D)cataracts.

Question 19

A piece of DNA that can use transposase to move from one place in the genome to another is known as a(n)

A)regulatory region
B)duplication.
C)translocation.
D)transposable element.

Question 20

What are the four major classes of chromosomal rearrangements?

A)Inversions, duplications, translocations, deletions
B)Duplications, reciprocal translocations, non-reciprocal translocations, inversions
C)Deletions, inversions, duplications, reciprocal translocations
D)Translocations, pericentric inversions, paracentric inversions, deletions

Question 21

In terms of evolution, what might be the outcome of repeated duplications of one or a few genes in a species' genome?

A)tetraploidy
B)semisterility
C)gene families
D)create repetitive DNA that is of no use to the cell.

Question 22

Which of the following does not usually show a problem during meiosis?

A)translocation heterozygote
B)translocation homozygote
C)paracentric inversion
D)pericentric inversion

Question 23

The condition of semisterility is most closely associated with

A)chromosomal duplications.
B)pericentric inversions.
C)translocation heterozygotes.
D)translocation homozygotes.

Question 24

Down syndrome can result from

A)three copies of chromosome 21.
B)a translocation of a part of chromosome 9.
C)a reciprocal translocation between any two autosomes.
D)trisomy X

Question 25

Which of the following is not an example of an aneuploidy?

A)monosomy
B)tetraploid
C)trisomy
D)tetrasomy

Question 26

Which of the following do translocations and inversions not have in common?

A)don't alter the amount of DNA in the genome
B)ability to alter gene function
C)use of inversion loops during crossing over
D)catalysts of speciation

Question 27

In terms of evolution, what might be the results of transposable elements in a species' genome?

A)novel mutations, some of which may be beneficial
B)transposons do not have any role in evolution
C)generation of potentially detrimental inversions
D)increase the point mutation rate of cells

Question 28

Turner syndrome, XO, is a sex chromosome aneuploidy.Of the effects listed below, which one is not usually seen in this syndrome?

A)unusually short stature
B)infertility
C)skeletal abnormalities
D)unusually long limbs

Question 29

What is NOT a mechanism by which transposon mobilization may be controlled by the cell?

A)Transcriptional control of the transposon genes
B)Translational control of transposon transcripts
C)Increased degradation of retrotransposon intermediates
D)Alternative splicing of a transposon transcript

Question 30

Which of the following sex chromosome aneuploidies is not usually seen in live births?

A)XO
B)XXY
C)YO
D)XXX

Question 31

Which is not a typical characteristic of transposable elements?

A)typically smaller than 50 bp
B)may be present in a genome from one to thousands of times
C)found only in a select group of organisms
D)need not be sequences that do something for the organism

Question 32

Barbara McClintock is most closely associated with which of the following?

A)the initial discovery of genetic transposition
B)the discovery of transposable elements in corn
C)the mutation rate in translocation heterozygotes
D)the demonstration of the presence of transposable elements in polytene chromosomes

Question 33

In terms of evolution, what might be the outcome of translocation in a species' genome?

A)production of gene families
B)development of two species due to reproductive isolation
C)eventual extinction due to semisterility
D)None of the choices is correct.

Question 34

What is the reason that aneuploidy in autosomal chromosomes is generally not tolerated as well as aneuploidy in sex chromosomes in humans?

A)Only one X chromosome is active in any somatic cell
B)Autosomal aneuplody leads to heart defects and death in utero
C)Y chromosome duplication results in only minor changes in testosterone levels
D)Sex chromosome aneuploids may occur as the result of fertilization but the any extra sex chromosomes are removed from the developing embryo during subsequent mitosis.
E)increased susceptibility to infection.

Question 35

One major difference between DNA and retrotransposons is that

A)During transposition retrotransposons go through an RNA form that is copied back into DNA
B)During transposition DNA transposons go through an RNA form that is copied back into DNA
C)In humans DNA transposons are the only type of transposons that move
D)DNA transposons are bordered by poly-A tracts

Question 36

Robertsonian translocations result from which of the following?

A)Breaks occur at or near the centromeres of two acrocentric chromosomes followed by the reciprocal exchange of broken parts.
B)A part of one chromosome becomes attached to a non-homologous chromosome.
C)Unequal crossing over occurs during meiosis.
D)There is fusion of two small chromosomes end-to-end such that a double centromere occurs.

Question 37

When a crossover occurs within the inversion loop of a pericentric inversion each recombinant chromatid will have

A)a dicentric bridge.
B)no duplications.
C)a deletion of some genes in the inverted region.
D)no mutations

Question 38

Of the following segregation patterns for chromosomes that have undergone reciprocal translocation, which one is most likely to result in a normal zygote?

A)alternate
B)adjacent-1
C)adjacent-2
D)nondisjunction

Question 39

Translocations can be used to

A)determine linkage groups for genes greater than 50 mu apart
B)determine linkage groups for genes only if they are less than 50 mu apart
C)create balancer chromosomes
D)create chromosomes with inversions

Question 40

A transposition is considered a cytologically invisible sequence rearrangement and therefore would be similar to which other type of mutation?

A)small deletion
B)large duplication
C)inversion
D)translocation

Question 41

How do chromosomal rearrangements generate new gene products?

A)Chromosome sets from different species
B)Translocations may result in the fusion of two different open reading frames.
C)Deletions may remove regulatory regions of genes.
D)Inversions may result in genes moving from a region of euchromatin to a region of heterochromatin.

Question 42

Transposable elements can cause deletions in genomes when

A)they transpose into a new site.
B)a non-autonomous transposon is activated by an autonomous transposon.
C)they are transcribed.
D)PiWi RNAs inhibit the transcription of the transposon.

Question 43

The genus Triticale is a new genus of the various allopolyploid hybrids between wheat and rye.Some of the members of this genus show agricultural promise because

A)wheat has a high yield.
B)rye adapts well to unfavorable environments.
C)wheat has a high level of protein.
D)rye has a high level of lysine.
E)All of the choices are correct.

Question 44

Any DNA segment that moves about in the genome

Question 45

Why are organisms with an odd number of chromosome sets usually sterile?

A)Almost all gametes will have an unbalanced set of chromosomes.
B)Chromosomes will fail to segregate independently during meiosis I
C)Chromosomes will fail to segregate independently during meiosis II
D)Since there is an odd number of chromosomal sets meiosis will not occur at all.

Question 46

Moves in the genome with the aid of an RNA intermediate

Question 47

Inversions can have an effect on the phenotype of the organism when

A)the trancscirbed region of a gene spans one or more of the inversion's breakpoints.
B)the inversion's breakpoints do not alter any of the inverted segments gene sequences.
C)the inversion is pericentric.
D)the inversion is paracentric.

Question 48

A change in the genome whereby copies of one or more genes are added to the genome

Question 49

A type of rearrangement where a piece of a chromosome is transferred to a non-homologous chromosome

Question 50

During mitosis, if all of the chromosomes in a diploid tissue fail to separate during anaphase one daughter cell will be

A)monoploid.
B)tetrasomic.
C)triploid.
D)tetraploid.

Question 51

Hybrids in which the chromosome sets come from two distinct, though related, species are known as

A)autopolyploids.
B)allopolyploids.
C)amphiploids.
D)bivalents.

Question 52

Match the description with the appropriate term


-Moves DNA directly

A) retroposon
B) transposon
C) transposable element
D) transposase

Question 53

Deletions can be useful for mapping

A)when the other allele is recessive that results in a viable but detectable phenotype
B)when the other allele is dominant.
C)if the other allele results in no detectable phenotype.
D)only when the individual has both alleles deleted.

Question 54

A change in the genetic material where a DNA sequence changes orientation

Question 55

In Drosophila, a gynandromorph, which is composed of equal parts of male and female tissue, results from

A)an XX female losing one X chromosome during the first mitotic division after fertilization.
B)an egg carrying an X chromosome fertilized by a Y-carrying sperm.
C)a normal egg fertilized by both an X-carrying sperm and a Y-carrying sperm.
D)the fusion of a female embryo with a male embryo.

Question 56

An enzyme that catalyzes a transposition event

Question 57

A type of rearrangement that results in a loss of genetic material from the genome

Question 58

Which of the following is not an example of a euploid condition?

A)triploidy
B)diploidy
C)trisomy 21
D)tetraploidy

Question 59

Triploid organisms usually result from

A)the union of haploid and diploid gametes.
B)unequal disjunction during embryogenesis.
C)propagation of fused cell lines.
D)fusion of three gametes simultaneously.

Question 60

A piece of genetic material that moves from place to place in the genome

Question 61

Monoploids are useful in plant breeding because

A)they can be grown into mature plants with desirable recessive traits.
B)none of the embryoids will have deleterious traits
C)they make it easier to create polyploid plants.
D)they are typically resistant to commercial herbicides.