Question 1

Barbara McClintock identified corn mutants with the unstable mutant phenotype with what pattern of color?

Accepted Answer

colorless with purple spots

Question 2

Compare and contrast the two types of transposable elements found in bacteria. Provide examples of how transposable elements can be both harmful and beneficial to bacteria.

Accepted Answer

Bacterial genomes contain two categories of transposable elements: insertion sequence (IS)elements and transposons. IS elements are simple transposable elements that contain only the sequences and genes necessary for autonomous transposition. Bacterial IS elements encode transposase and are flanked by inverted repeat sequences unique to each insertion sequence. Transposons, on the other hand, can carry multiple genes and confer new traits on the bacteria that contain them. The process of transposition is a mutational event that can inactivate or alter normal gene expression. Both types of transposable elements can produce mutations if they are inserted into a wild-type gene. These mutations are often harmful if they disrupt the function of a normal gene. Conservative and simple bacterial transposons may be beneficial to the cell in that they often carry the gene for transposase and genes for antibiotic or heavy metal resistance.

Question 3

When nondisjunction occurs early in embryogenesis rather than gametogenesis, what would you expect in the resulting karyotype?

Accepted Answer

A) monosomy 
B) trisomy 
C) mosaicism 
D) uniparental disomy 
E) random X-inactivation 
A) monosomy 
B) trisomy 
C) mosaicism 
D) uniparental disomy 
E) random X-inactivation C

Question 4

During gametogenesis, what percentage of gametes would be aneuploid if the nondisjunction event occurs during meiosis I?

Accepted Answer

The answer of During gametogenesis, what percentage of gametes would...

Question 5

During gametogenesis, what percentage of gametes would be trisomic if the nondisjunction event occurs during meiosis II?

Accepted Answer

The answer of During gametogenesis, what percentage of gametes would...

Question 6

P elements in Drosophila contribute to the process of hybrid dysgenesis, which occurs when M-cytotype females are crossed with P-cytotype males.
What does the model of hybrid dysgenesis predict for the F1 and F2 generations when a P-cytotype male is crossed to an M-cytotype female?

Accepted Answer

F₁ will be

Question 7

If an organism is an inversion heterozygote, __________.

Accepted Answer

A) homologous chromosomes align during meiosis through formation of an inversion loop at synapsis 
B) homologous chromosomes align during meiosis through formation of a Holliday junction at synapsis 
C) non-homologous chromosomes pair during meiosis due to the translocation of genes between two different chromosomes 
D) it will experience normal chromosome synapsis during meiosis 
E) it will be unable to complete replication due to DNA damage, and the cell cycle will be arrested 
A) homologous chromosomes align during meiosis through formation of an inversion loop at synapsis 
B) homologous chromosomes align during meiosis through formation of a Holliday junction at synapsis 
C) non-homologous chromosomes pair during meiosis due to the translocation of genes between two different chromosomes 
D) it will experience normal chromosome synapsis during meiosis 
E) it will be unable to complete replication due to DNA damage, and the cell cycle will be arrested

Question 8

In McClintock's maize studies, which genetic element is found at the site of chromosome breakage?

Accepted Answer

dissociati

Question 9

A partial chromosome deletion or duplication can be observed at prophase I homologous chromosome synapsis during meiosis by looking for what structure?

Accepted Answer

The answer of A partial chromosome deletion or duplication can...

Question 10

Pseudodominance is used to map genes by using what method?

Accepted Answer

The answer of Pseudodominance is used to map genes by...

Question 11

P elements cause which phenomenon responsible for sterility in Drosophila?

Accepted Answer

The answer of P elements cause which phenomenon responsible for...

Question 12

How is aneuploidy different from polyploidy? What are the mechanisms by which aneuploidy and polyploidy are caused, and what are the consequences of these chromosomal alterations in terms of survival and fertility of the offspring?

Accepted Answer

Aneuploidy occurs when one or more chrom

Question 13

Of the three mechanisms leading to autopolyploidy, which is the most rare event?

Accepted Answer

multiple f

Question 14

How are retroviruses and retrotransposons similar? Describe the genes encoded by the DNA of the retrovirus and the two DNA elements consistently found in retrotransposons.

Accepted Answer

Retroviruses are viruses that infect euk

Question 15

What does the model of hybrid dysgenesis predict for the F1 and F2 generations when an M-cytotype male is crossed to a P-cytotype female?

Accepted Answer

F₁ and F₂ will be wild

Question 16

In bacteria, what is contained within the IS elements?

Accepted Answer

A) transposase gene 
B) short tandem repeats 
C) inverted repeats 
D) Both A and B are correct. 
E) Both A and C are correct. 
A) transposase gene 
B) short tandem repeats 
C) inverted repeats 
D) Both A and B are correct. 
E) Both A and C are correct.

Question 17

If you wish to target a retrovirus in a cell but do not want to disrupt retrotransposons, which gene(s)would you target?

Accepted Answer

Target env or gag, since they

Question 18

Gametes produced by inversion heterozygotes can produce no viable recombinant chromosomes due to what phenomenon?

Accepted Answer

crossover

Question 19

Which type of chromosome deletion is caused by two concurrent chromosome breaks (rather than a single break)?

Accepted Answer

A) acentric deletion 
B) microdeletion 
C) terminal deletion 
D) partial deletion 
E) interstitial deletion 
A) acentric deletion 
B) microdeletion 
C) terminal deletion 
D) partial deletion 
E) interstitial deletion

Question 20

In Drosophila and Lepidoptera, sex-chromosome mosaicism produces what type of sexually ambiguous phenotype?

Accepted Answer

The answer of In Drosophila and Lepidoptera, sex-chromosome mosaicism produces...

Exam 13: Chromosome Aberrations and Transposition

Barbara McClintock identified corn mutants with the unstable mutant phenotype with what pattern of color?

Compare and contrast the two types of transposable elements found in bacteria. Provide examples of how transposable elements can be both harmful and beneficial to bacteria.

When nondisjunction occurs early in embryogenesis rather than gametogenesis, what would you expect in the resulting karyotype?

During gametogenesis, what percentage of gametes would be aneuploid if the nondisjunction event occurs during meiosis I?

During gametogenesis, what percentage of gametes would be trisomic if the nondisjunction event occurs during meiosis II?

P elements in Drosophila contribute to the process of hybrid dysgenesis, which occurs when M-cytotype females are crossed with P-cytotype males. What does the model of hybrid dysgenesis predict for the F1 and F2 generations when a P-cytotype male is crossed to an M-cytotype female?

If an organism is an inversion heterozygote, __________.

In McClintock's maize studies, which genetic element is found at the site of chromosome breakage?

A partial chromosome deletion or duplication can be observed at prophase I homologous chromosome synapsis during meiosis by looking for what structure?

Pseudodominance is used to map genes by using what method?

P elements cause which phenomenon responsible for sterility in Drosophila?

How is aneuploidy different from polyploidy? What are the mechanisms by which aneuploidy and polyploidy are caused, and what are the consequences of these chromosomal alterations in terms of survival and fertility of the offspring?

Of the three mechanisms leading to autopolyploidy, which is the most rare event?

How are retroviruses and retrotransposons similar? Describe the genes encoded by the DNA of the retrovirus and the two DNA elements consistently found in retrotransposons.

What does the model of hybrid dysgenesis predict for the F1 and F2 generations when an M-cytotype male is crossed to a P-cytotype female?

In bacteria, what is contained within the IS elements?

If you wish to target a retrovirus in a cell but do not want to disrupt retrotransposons, which gene(s)would you target?

Gametes produced by inversion heterozygotes can produce no viable recombinant chromosomes due to what phenomenon?

Which type of chromosome deletion is caused by two concurrent chromosome breaks (rather than a single break)?

In Drosophila and Lepidoptera, sex-chromosome mosaicism produces what type of sexually ambiguous phenotype?

The Molecular Basis of Heredity, Variation, and Evolution

Transmission Genetics

Cell Division and Chromosome Heredity

Gene Interaction

Genetic Linkage and Mapping in Eukaryotes

Genetic Analysis and Mapping in Bacteria and Bacteriophages

Dna Structure and Replication

Molecular Biology and Transcription and Rna Processing

The Molecular Biology of Translation

The Integration of Genetic Approaches: Understanding Sickle Cell Disease

Chromosome Structure

Gene Mutation, Dna Repair, and Homologous Recombination

Regulation of Gene Expression in Bacteria and Bacteriophages

Regulation of Gene Expression in Eukaryotes

Forward Genetics and Recombinant Dna Technology

Applications of Recombinant Dna Technology and Reverse Genetics

Genomics: Genetics From a Whole-Genome Perspective

Cytoplasmic Inheritance and the Evolution of Organelle Genomes

Developmental Genetics

Genetic Analysis of Quantitative Traits

Population Genetics and Evolution

Filters

P elements in Drosophila contribute to the process of hybrid dysgenesis, which occurs when M-cytotype females are crossed with P-cytotype males. What does the model of hybrid dysgenesis predict for the F₁ and F₂ generations when a P-cytotype male is crossed to an M-cytotype female?

What does the model of hybrid dysgenesis predict for the F₁ and F₂ generations when an M-cytotype male is crossed to a P-cytotype female?