Question 1

A deletion may set up a genetic circumstance known as overdominance.

Accepted Answer

A) True 
 B)False  False

Question 2

Assume that an organism has a diploid chromosome number of 14.There would be 28 chromosomes in a tetraploid.

Accepted Answer

A) True 
 B)False  True

Question 3

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

Accepted Answer

A) True 
 B)False  False

Question 4

rDNA in eukaryotes is typically redundant.

Accepted Answer

A) True 
 B)False

Question 5

Inversions and translocations are without evolutionary significance.

Accepted Answer

A) True 
 B)False

Question 6

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

Accepted Answer

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

Question 7

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 8

Fragile-X syndrome (or Martin-Bell syndrome)is the most common form of inherited mental retardation in humans.Is it more common in males or females? What is FMR1?

Accepted Answer

males (1/4000 compared to 1/80

Question 9

Familial Down syndrome can be caused by a translocation between chromosomes 1 and 14.

Accepted Answer

A) True 
 B)False

Question 10

Under what circumstance can an individual with Down syndrome have 46 chromosomes?

Accepted Answer

if he or she carries

Question 11

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 3[2]: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?

Accepted Answer

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

Question 12

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.What would be a likely explanation for this observation? Explain with a labeled diagram.

Accepted Answer

A four-strand double crossover

Question 13

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

Accepted Answer

By interfering with spindle fo

Question 14

A pericentric inversion includes the centromere.

Accepted Answer

A) True 
 B)False

Question 15

What explanation is generally given for lethality of monosomic individuals?

Accepted Answer

Monosomy may unmask recessive

Question 16

An individual with Patau syndrome would be called a triploid.

Accepted Answer

A) True 
 B)False

Question 17

A paracentric inversion is one whose break points do not flank the centromere.

Accepted Answer

A) True 
 B)False

Question 18

Clearly illustrate the pairing configuration of an inversion (paracentric)heterokaryotype.

Accepted Answer

The pairing of homologous chro

Question 19

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

Accepted Answer

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

Question 20

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

Accepted Answer

A) True 
 B)False

Exam 6: Chromosome Mutations: Variation in Number and Arrangement

A deletion may set up a genetic circumstance known as overdominance.

Assume that an organism has a diploid chromosome number of 14.There would be 28 chromosomes in a tetraploid.

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

rDNA in eukaryotes is typically redundant.

Inversions and translocations are without evolutionary significance.

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

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.

Fragile-X syndrome (or Martin-Bell syndrome)is the most common form of inherited mental retardation in humans.Is it more common in males or females? What is FMR1?

Familial Down syndrome can be caused by a translocation between chromosomes 1 and 14.

Under what circumstance can an individual with Down syndrome have 46 chromosomes?

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

A pericentric inversion includes the centromere.

What explanation is generally given for lethality of monosomic individuals?

An individual with Patau syndrome would be called a triploid.

A paracentric inversion is one whose break points do not flank the centromere.

Clearly illustrate the pairing configuration of an inversion (paracentric)heterokaryotype.

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

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

Introduction to Genetics

Mitosis and Meiosis

Mendelian Genetics

Modification of Mendelian Ratios

Sex Determination and Sex Chromosomes

Linkage and Chromosome Mapping in Eukaryotes

Genetic Analysis and Mapping in Bacteria and Bacteriophages

DNA structure and Analysis

DNA Replication and Recombination

Chromosome Structure and DNA Sequence Organization

The Genetic Code and Transcription

Translation and Proteins

Gene Mutation,DNA Repair,and Transposition

Regulation of Gene Expression

The Genetics of Cancer

Recombinant DNA Technology

Genomics,Bioinformatics,and Proteomics

Applications and Ethics of Genetic Engineering and Biotechnology

Developmental Genetics

Quantitative Genetics and Multifactorial Traits

Population and Evolutionary Genetics

Conservation Genetics

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