Which of the following descriptions of chromosomes is not correctly matched?
description of a telocentric chromosome.
D) Telocentric — there is only one chromosome arm.This is a correct description of a telocentric chromosome.
Which of the following is not a type of chromosomal mutation?
A) All of these are chromosomal mutations.
A duplication is:
A) The presence of an extra copy of a piece of chromosomal material.
Which explanation for the loss of a terminal piece of a chromosome makes the
most sense?
a) Only pieces of DNA with centromeres are correctly sorted into daughter nuclei
during mitosis.
b) Only pieces of DNA with telomeres are correctly sorted into daughter nuclei
during mitosis.
c) This piece of DNA is recognized as foreign by the cell.
d) A and B
e) None of these.
a) Only pieces of DNA with centromeres are correctly sorted into daughter nuclei during mitosis.
Which technique can be used to quickly identify large deficiencies?
A) Karyotype analysis.
Why might gene duplication allow for generation of more genetic variability?
a) The second copy of the gene could be expressed under different regulation.
b) The second copy of the gene could accumulate mutations which would be lethal if
only one copy were present.
c) The second copy of the gene could be deleted without effect on the organism.
d) A and B.
e) None of the above.
d) A and B.
Which statement regarding the human globin genes is likely to be correct?
a) Myoglobin is probably more similar to α-globin than is β-globin.
b) α-globin and β-globin are probably more similar to each other than they are to
myoglobin.
c) The globin genes in mice are probably more similar to those of humans than are
globin genes of chimpanzees.
d) All of these.
e) None of these.
b) α-globin and β-globin are probably more similar to each other than they are to myoglobin.
Which of the following chromosomal rearrangements would you expect to have the
least phenotypic effect on the organism?
A) A paracentric inversion.
Why are unaffected carriers of inversions likely to produce genetically abnormal
progeny?
a) The inversion chromosome is more likely to be placed in a gamete than the normal
chromosome.
b) The inversion chromosome is unable to accomplish synapsis with the normal
chromosome during meiosis.
c) Crossovers cannot occur between inversion and normal chromosomes.
d) Crossovers between the inversion and normal chromosomes lead to chromosomes with
deletions, deficiencies, or abnormal structure.
d) Crossovers between the inversion and normal chromosomes lead to chromosomes with
deletions, deficiencies, or abnormal structure.
What do deficiencies, inversions, and translocations have in common?
B) They all can be caused by DNA breakage and inaccurate repair.
What do inversions and balanced translocations have in common?
D) All of these.
Which of the following is an example of a euploid individual?
D) A plant of a new wheat species with twice the usual number of chromosomes.
Which of the following terms could be used to describe the individual whose
karyotype is shown in Fig 8.1c?
A) Diploid.
If X inactivation in humans shuts down extra X chromosomes, why do XXY and XXX
individuals show any phenotypic effects?
E) Some X linked genes escape inactivation.
Which of the following might cause nondisjunction?
A) Failure of synapsis in meiosis I.
An allotetraploid species:
C) All of these.
Deletions tend to be less harmful than duplications.
a) True
b) False
b) False
Members of a gene family may be created by abnormal crossing over.
a) True
b) False
a) True
Inversions tend to have more serious phenotypic effects than other chromosomal
rearrangements.
a) True
b) False
b) False
Alternate and adjacent-1 segregation are equally likely to produce nonviable
gametes.
a) True
b) False
b) False
Aneuploidy is usually a lethal condition in humans.
a) True
b) False
a) True
While plants can often exist as polyploid species, animals cannot.
a) True
b) False
b) False
All of the cells within an individual are genetically identical.
a) True
b) False
b) False
An allodiploid can be created by fusion of diploid gametes.
a) True
b) False
b) False
Comparative genomic hybridization is used to detect
D) both A and B.
In comparative genomic hybridization, if the green to red ratio is greater than
one, this suggests a
B) chromosome duplication.
In the comparative genomic hybridization experiment of Kallioniemi and Pinkel,
the green DNA was from cancer cells and the red DNA was from
C) a sample of normal cells.
In comparative genomic hybridization, which samples are fluorescently labeled?
B) Only A and B
In the data of Figure 8.8, a deletion was observed in the short arm of
chromosome 9. Let's suppose a researcher made a mistake and added twice as much
of the normal DNA compared to the cancer DNA. In this deleted region of
chromosome 9, the ratio of green to red fluorescence would be
B) 0.25
homologous
describes the analogous chomosomes from evolutionarily related species.
paracentric inversion
an inversion in which the centromere is found outside of the inverted region
telomere
specialized DNA sequences found at the ends of eukaryotic, linear chromosomes
euploid
describes an organism in which the chomosome number is an exact multple of chomosome set
triploid
a organism or cell that contains three sets of chromosomes
polyploid
an organism or cell with three or more sets of chromosomes
nondisjunction
event in which chromosomes do not segregate properly during mitosis or meiosis
monoploid
an organism with a single set of chromosomes within its somatic cells
polytene chromosome
chromosomes that are found in certian cells, such as Drosophilia salivary cells, in which the chomosomes have replicated many times and the copies lie side by side
chromocenter
the central point where polytene chomosomes aggregate
chromomere
a dark band within a polytene chromosome
meiotic nondisjunction
condition in which chromosomes do not segregate equally into the gametes during meiosis
alloploid
an event in which chromosomes do not segregate equally during mitosis
mosaicism
when the cells of part of an organism differ genetically from the rest of the organism
autopolyploid
a polyploid produced within a single species due to nondisjunction
allopolyploid
an organism that contains two or more sets of chromosomes from two (or more) species
homeologous
describes the analogus chromosomes from evolutionarily related species
cell fusion
describes the process in which individual cells are mixed together and made to fuse
heterokaryon
a cell produced from cell fusion that contains two separate nuclei
heterosis
Heterosis is usually different from over dominance because the hybrid may be heterozygous for many genes, not just a single gene, and because the superior phenotyp may be due to the masking of deleterious recessive allels.
genetic variation
genetic differences among members of the same species or among different species
chromosome mutation
a substantial change in chromosome structure that may affect more than a single gene.
genome mutation
a change in chromosome number
metacentric
describes a chromosome with the centromere in the middle
submetacentric
describes a chromosome in which the centromere is slightly off center
acrocentric
describes a chromosome with the centromre significantly off center, but not at the very end.
telocentric
describes a chromosome with its centromere at one end
karyotype
a photographic representation of all the chromosomes within a cell. It reveal how many chromosomes are found within an actively dividing somatic cell.
deficiency
condition in which a segment of chromosomal material is missing
deletion
condition in which a segment of chromosomal material is missing
duplication
the copying of a segment of DNA
inversion
a change in the orientation of genetic material along a chromosome
translocation
when one segment of a chromosome breaks off and becaomes attached to a different chromosome
pseudodominance
a pattern of inheritance that occurs when a single copy of a recessive allele is phenotypically expressed because the second copy of the gene has been deleted from the chromosome
polytene chromosomes
chromosomes that are found in the certian cells, such as Drosophila salivary cells, in which the chromosomes have replicated many times and the copies lie side by side
position effect
a change in phenotype that occurs when the position of a gene is changed from one chromosomal site to a different location
gene family
two or more different genes that are homologous to each other because they were derived from the same ancestral gene
protoplast
a plant cell without a cell wall
Author
hbic_1
ID
118444
Card Set
Genetics Ch.8: Variation in Chromosome Structure and Number
Description
Genetics Ch.8: Variation in Chromosome Structure and Number
