Question 1

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

Accepted Answer

A) True 
 B)False  True

Question 2

Nondisjunction is viewed as a major cause of aneuploidy.

Accepted Answer

A) True 
 B)False  True

Question 3

In what way might gene duplication play a role in evolution?

Accepted Answer

In 1970,Susumu Ohno proposed that gene duplication provides a way in which new genes arise.By duplicating a gene,the duplicated copy or the original gene is able to mutate without necessarily having an adverse influence on the phenotype.

Question 4

Describe the maternal age effect associated with Down syndrome.

Accepted Answer

For unknown reasons,the nondis

Question 5

Chorionic villus sampling (CVS)is sometimes preferred to amniocentesis because results can be provided earlier in the pregnancy.

Accepted Answer

A) True 
 B)False

Question 6

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

Accepted Answer

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

Question 7

Gene duplications provide an explanation for the origin of gene families.

Accepted Answer

A) True 
 B)False

Question 8

rDNA in eukaryotes is typically redundant.

Accepted Answer

A) True 
 B)False

Question 9

In general,inversion and translocation heterozygotes are as fertile as organisms whose chromosomes are in the standard arrangement.

Accepted Answer

A) True 
 B)False

Question 10

The chromosomal aberration that causes cri du chat syndrome can be referred to as a segmental deletion.

Accepted Answer

A) True 
 B)False

Question 11

What is meant by the terms acentric and dicentric?

Accepted Answer

A chromosome without

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 3(2):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?

Accepted Answer

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

Question 13

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

Accepted Answer

A) True 
 B)False

Question 14

A position effect occurs when a gene's expression is altered by virtue of a change in its position.One might expect position effects to occur with inversions and translocations.

Accepted Answer

A) True 
 B)False

Question 15

In Drosophila melanogaster (2n = 8),a fly with seven chromosomes could be called a haplo-IV.

Accepted Answer

A) True 
 B)False

Question 16

The term aneuploidy is synonymous with the term segmental deletion.

Accepted Answer

A) True 
 B)False

Question 17

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

Accepted Answer

By interfering with spindle fo

Question 18

A pericentric inversion includes the centromere.

Accepted Answer

A) True 
 B)False

Question 19

Inversions and translocations are without evolutionary significance.

Accepted Answer

A) True 
 B)False

Question 20

Inversions suppress crossing over by providing a chemical imbalance because of breakpoints within certain genes.

Accepted Answer

A) True 
 B)False

Exam 8: Chromosome Mutations: Variation in Number and Arrangement

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

Nondisjunction is viewed as a major cause of aneuploidy.

In what way might gene duplication play a role in evolution?

Describe the maternal age effect associated with Down syndrome.

Chorionic villus sampling (CVS)is sometimes preferred to amniocentesis because results can be provided earlier in the pregnancy.

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

Gene duplications provide an explanation for the origin of gene families.

rDNA in eukaryotes is typically redundant.

In general,inversion and translocation heterozygotes are as fertile as organisms whose chromosomes are in the standard arrangement.

The chromosomal aberration that causes cri du chat syndrome can be referred to as a segmental deletion.

What is meant by the terms acentric and dicentric?

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

A position effect occurs when a gene's expression is altered by virtue of a change in its position.One might expect position effects to occur with inversions and translocations.

In Drosophila melanogaster (2n = 8),a fly with seven chromosomes could be called a haplo-IV.

The term aneuploidy is synonymous with the term segmental deletion.

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

A pericentric inversion includes the centromere.

Inversions and translocations are without evolutionary significance.

Inversions suppress crossing over by providing a chemical imbalance because of breakpoints within certain genes.

Introduction to Genetics

Mitosis and Meiosis

Mendelian Genetics

Extensions of Mendelian Genetics

Chromosome Mapping in Eukaryotes

Genetic Analysis and Mapping in Bacteria and Bacteriophages

Sex Determination and Sex Chromosomes

Extranuclear Inheritance

DNA Structure and Analysis

DNA Replication and Recombination

DNA Organization in Chromosomes

The Genetic Code and Transcription

Translation and Proteins

Gene Mutation,dna Repair,and Transposition

Regulation of Gene Expression in Prokaryotes

Regulation of Gene Expression in Eukaryotes

Developmental Genetics

Cancer and Regulation of the Cell Cycle

Recombinant DNA Technology

Genomics, bioinformatics, and Proteomics

Applications and Ethics of Genetic Engineering and Biotechnology

Quantitative Genetics and Multifactorial Traits

Neurogenetics

Population and Evolutionary Genetics

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