A(n) ___ within a chromosome changes the amount of DNA in that chromosome.

translocation

inversion

deletion

point mutation

Answer: C

A ___ inversion is a rearrangement of DNA that involves the centromere.

translocated

pericentric

submetacentric

paracentric

Answer: B

_________ results in multiple complete chromosome sets.

Tandem duplication

Nondisjunction

Aneuploidy

Polyploidy

Answer: D

A mutation event occurs in which two different (nonhomologous) chromosomes end up with a small piece of the other. This mutation is a(n)

paracentric inversion.

intrachromosomal translocation.

intrachromosomal duplication.

interchromosomal translocation.

Answer: D

Chromosomal mutations in prokaryotes or eukaryotes may occur

as the result of exposure to chemicals. Therefore, all the choices listed are correct.

as the result of exposure to radiation.

spontaneously

All of the choices listed are correct.

Answer: D

Dicentric or acentric chromosomes may arise as a result of

translocation.

paracentric inversion.

duplication.

deletion.

Answer: B

For which type of chromosomal mutation would it be impossible to revert to wild type?

deletion

translocation

duplication

inversion

Answer: A

During cell division, a dicentric chromosome typically experiences _______ while an acentric chromosome is ________________.

duplication; unaffected

inversion; unaffected

breakage; reintegrated

breakage; lost

Answer: D

Humans have ___ complete set(s) of ___ chromosomes.

one; 23

two; 23

one; 46

two; 46

Answer: B

Which of the following human disorders is NOT caused by aneuploidy?

Down syndrome

Cri-du-chat syndrome

Edwards syndrome

Patau syndrome

Answer: B

In pseudodominance, the dominant allele of a gene is ______, and the recessive allele is _________.

deleted; expressed

expressed; masked

expressed; deleted

deleted; masked

Answer: A

Monoploidy is rarely seen in adults of normally diploid organisms because

meiosis is affected.

mitosis is affected.

recessive alleles are uncovered.

recessive lethal mutations are uncovered.

Answer: D

Prader-Willi syndrome is associated with a deletion of part of which chromosome?

1

5

15

21

Answer: C

The sons of a woman with one fragile X chromosome have a ___ chance of inheriting the mutation.

0%

25%

50%

100%

Answer: C

The order of genes on a particular DNA segment is A-B-C-D-E . After a chromosomal mutation, the order is A-D-C-B-E . This mutation is a(n)

translocation.

duplication.

inversion.

deletion.

Answer: C

The phenotypic effects of fragile X syndrome are exhibited primarily in

males.

females.

approximately equal numbers of males and females.

XXY females.

Answer: A

The Philadelphia chromosome observed in people with chronic myelogenous leukemia results from which chromosomal mutation?

terminal tandem duplication

reciprocal translocation

pericentric inversion

deletion

Answer: B

The sequence of genes on a particular region of the chromosome is A-B-C-D-E . After a chromosomal mutation, the sequence is A-B-C-C-B-D-E . This is a(n) ___ mutation.

reverse tandem duplication

intrachromosomal translocation

paracentric inversion

None of the choices listed is correct.

Answer: A

Polyploidy is more commonly found in plants than in other normally diploid organisms. What are possible reasons?

Plants can self-fertilize.

Many plants are naturally polyploid.

Plants can be propagated vegetatively.

All of the reasons listed may contribute to the natural phenomenon of polyploidy in plants.

Answer: D

Which of the following types of aneuploidy would be LEAST likely to cause problems in meiosis?

monosomy

trisomy

tetrasomy

All of the choices listed are equally likely to cause problems in meiosis.

Answer: C

In polytene chromosomes from Drosophila, genes are found in the

chromocenter.

bands.

interbands.

bands and interbands.

Answer: D

Individuals with Down syndrome have ___ of chromosome 21.

one copy

two copies

three copies

no copies

Answer: C

Polyploidy is rare in mammals, but is commonly found in

birds and reptiles.

algae and birds.

amphibians and plants.

insects and fungi.

Answer: C

Chimpanzees and gorillas have a chromosomal complement of 2N = 48, whereas humans have 2N = 46. Genetic analysis has revealed that two chromosomes in the apes chromosomes show homology with human chromosome 2. This is a good example of ________ in evolution.

Robertsonian fusion

duplication

inversion

All of the choices listed are correct.

Answer: A

A meiotically or mitotically heritable change in gene expression that does not involved a change in the DNA sequence of the affected gene(s) is referred to as

cytogenetics.

epigenetics.

euploidy.

pseudodominance.

Answer: B