Question 1

How does DNA methylation contribute to the repression of transcription?

Accepted Answer

DNA methylation is an epigenetic mechani...

Question 2

Which of the following is NOT a defining feature of paramutation?

Accepted Answer

A)   The expression pattern is transmitted to future generations.
B)   The altered allele is able to convert other alleles.
C)   No DNA sequence differences exist between alleles.
D)   Mutation of coding sequences generates new alleles.
E)   These are all defining features of paramutation.F) A) and B)
G) A) and C)

Question 3

Which of the following stimulates the transcription of Xist on the active X chromosome?

Accepted Answer

A)   Xist
B)   Tsix
C)   Jpx
D)   Xite
E)   Xist is not transcribed on the active X chromosome.F) D) and E)
G) C) and D)

Question 4

Explain how studies in mice suggest that diet can cause epigenetic changes that are transmitted through generations.

Accepted Answer

Studies in mice have shown that diet can...

Question 5

A group of scientists is studying memory in mice. They feed sodium butyrate, a histone deacetylase inhibitor, to a group of older mice and then subject them to memory exercises. How do you predict the memory of treated mice might compare with the memory of untreated mice?

Accepted Answer

A)   Histone acetylation increases with age, so sodium butyrate may improve memory in older mice.
B)   Histone acetylation increases with age, so sodium butyrate may impair memory in older mice.
C)   Histone acetylation decreases with age, so sodium butyrate may improve memory in older mice.
D)   Histone acetylation decreases with age, so sodium butyrate may impair memory in older mice.
E)   Histone acetylation is not associated with memory in mice.F) B) and E)
G) A) and E) C

Question 6

A beekeeper notices that her bee population is declining rapidly. Upon further study, she notices that there are no queen bees present in her population. She suspects this is due to exposure to an environmental agent. Which of the following could be a possible mechanism for the environmental agent?

Accepted Answer

A)   The environmental agent inhibits Dnmt3.
B)   The environmental agent causes royal jelly to be produced in abnormally high amounts.
C)   The environmental agent mimics a Dnmt3 siRNA.
D)   The environmental agent is causing extensive chromosome rearrangements within the genome of the queen bees.
E)   The environmental agent is a methyltransferase enzyme that acts on genes that encode queen bee characteristics.F) D) and E)
G) A) and C)

Question 7

What effect would the deamination of 5-methylcytosine in a promoter have on the expression of that gene?

Accepted Answer

A)   The gene will have increased expression because this chemical reaction will result in unmethylated cytosine.
B)   The gene will have increased expression because this chemical reaction will result in thymine.
C)   The gene will have increased expression because this chemical reaction will result in uracil.
D)   The gene will have decreased expression because this chemical reaction will result in unmethylated cytosine.
E)   The gene will have decreased expression because this chemical reaction will result in uracil.F) B) and E)
G) None of the above

Question 8

What do you expect would develop if you injected Dnmt3 siRNA into honeybee larvae?

Accepted Answer

A)   a male drone
B)   a female worker
C)   a female queen
D)   a male drone or a female worker
E)   a female worker or a queenF) A) and B)
G) B) and E)

Question 9

How long is Xist RNA?

Accepted Answer

A)   21 bp
B)   500 bp
C)   1500 bp
D)   17,000 bp
E)   230,000 bpF) A) and B)
G) A) and C)

Question 10

Compare the effects of the environment on the epigenetics of glucocorticoid receptor expression in mice and humans.

Accepted Answer

The effects of the environment on the ep...

Question 11

What type of enzyme would MOST likely promote increased gene expression?

Accepted Answer

A)   DNA methyltransferase
B)   DNA demethylase
C)   DNA polymerase
D)   DNA ligase
E)   DNAseF) A) and B)
G) A) and C)

Question 12

When does paternal X inactivation occur in mice? (Select all that apply.)

Accepted Answer

A)   at fertilization
B)   8-cell stage of embryo
C)   blastocyst maturation
D)   at birth
E)   within 10 days after birthF) A) and D)
G) D) and E)

Question 13

Consider a hypothetical gene in mice called the can gene. The mutant form of this gene causes skin cancer and behaves in a dominant manner. A mouse with skin cancer was studied to determine the location of the mutation in the can gene. However, when scientists sequenced both maternal and paternal copies of the gene, they could not identify any mutation in the gene. What is a possible explanation for the mouse's skin cancer?

Accepted Answer

A)   One of the copies of the can gene could be hypermethylated and thus transcriptionally inactive in the mouse.
B)   One of the copies of the can gene could have an inversion that renders it nonfunctional.
C)   Both copies of the can gene must have the exact same mutation and, therefore, the sequencing reaction could not detect the location of the mutation.
D)   One of the copies of the can gene could be deacetylated and thus transcriptionally inactive in the mouse.
E)   The only possible explanation is that it is a different gene at a different locus that is causing the skin cancer in the mouse.F) C) and E)
G) B) and D)

Question 14

Kit+Kit+ mice were crossed with Kit+Kitt mice. The embryos resulting from this cross were then injected with miRNAs specific to Kit mRNA. What phenotype will these embryos develop to have?

Accepted Answer

A)   All mice will have the wild-type phenotype.
B)   All mice will have the mutant phenotype.
C)   The Kit+Kit+ mice will have the wild-type phenotype, and the Kit+Kitt mice will have the mutant phenotype.
D)   The Kit+Kit+ mice will have more mutant phenotypes than wild-type phenotypes, and the Kit+Kitt mice will have the mutant phenotype.
E)   The Kit+Kit+ mice will have the wild-type phenotype, and the Kit+Kitt mice will have a 1:1 ratio of the wild-type to mutant phenotype.F) B) and E)
G) A) and D)

Question 15

Which of the following is NOT affected by genomic imprinting?

Accepted Answer

A)   Angelman syndrome
B)   Prader-Willi syndrome
C)   Beckwith-Wiedemann syndrome
D)   Igf2 alleles in mice
E)   Down syndromeF) A) and B)
G) A) and C)

Question 16

Describe three important features that define paramutation.

Accepted Answer

Paramutation is a phenomenon in genetics that involves the transfer of epigenetic information from one allele to another, resulting in heritable changes in gene expression. Three important features that define paramutation include:

1. Heritability: Paramutation results in heritable changes in gene expression that can be passed on to future generations. This is a key feature that distinguishes paramutation from other forms of gene regulation.

2. Epigenetic regulation: Paramutation involves the transfer of epigenetic information, such as DNA methylation or histone modifications, from one allele to another. This epigenetic modification leads to stable changes in gene expression without altering the DNA sequence itself.

3. Allelic interaction: Paramutation occurs through interactions between two different alleles of the same gene. One allele, known as the paramutagenic allele, induces heritable changes in the expression of the other allele, known as the paramutable allele. This interaction between alleles is essential for the establishment and maintenance of paramutation.

These three features collectively define paramutation as a unique and heritable form of gene regulation that involves epigenetic modifications and allelic interactions. Understanding paramutation is important for unraveling the complexities of gene regulation and inheritance in genetics.

Question 17

Which of the following statements is NOT true of DNA methylation?

Accepted Answer

A)   It is associated with transcription repression.
B)   It occurs on cytosines adjacent to guanines.
C)   Cytosines on both strands are usually methylated.
D)   It is carried out by DNA methyltransferases.
E)   Methylation is permanent and cannot be reversed.F) C) and D)
G) A) and B)

Question 18

Which of the following stimulates the transcription of Xist on the inactive X chromosome?

Accepted Answer

A)   Xist
B)   Tsix
C)   Jpx
D)   Xite
E)   Xist is not transcribed on the inactive X chromosome.F) A) and B)
G) C) and D)

Question 19

Which statement BEST described how imprinting varies over the course of development?

Accepted Answer

A)   Imprinted alleles are permanently silenced from embryo development through adulthood.
B)   Imprinting is only active during embryo development, but expression returns to normal during adulthood.
C)   Imprinting is only active during gametogenesis, where alleles are selectively silenced before being transmitted to offspring.
D)   Imprinting randomly flickers on and off during development.
E)   Imprinted alleles differ by tissue type and time of development.F) B) and D)
G) None of the above E

Question 20

List three types of molecular mechanisms that alter chromatin structure and underlie many epigenetic phenotypes.

Accepted Answer

Three types of molecular mechanisms that...

Exam 21: Epigenetics

How does DNA methylation contribute to the repression of transcription?

Correct Answer
Answered by ExamLex AI
DNA methylation is an epigenetic mechani...
View Answer

Which of the following is NOT a defining feature of paramutation?

Correct Answer
verified

Which of the following stimulates the transcription of Xist on the active X chromosome?

Correct Answer
verified

Explain how studies in mice suggest that diet can cause epigenetic changes that are transmitted through generations.

Correct Answer
Answered by ExamLex AI
Studies in mice have shown that diet can...
View Answer

A group of scientists is studying memory in mice. They feed sodium butyrate, a histone deacetylase inhibitor, to a group of older mice and then subject them to memory exercises. How do you predict the memory of treated mice might compare with the memory of untreated mice?

Correct Answer
verified
C

A beekeeper notices that her bee population is declining rapidly. Upon further study, she notices that there are no queen bees present in her population. She suspects this is due to exposure to an environmental agent. Which of the following could be a possible mechanism for the environmental agent?

Correct Answer
verified

What effect would the deamination of 5-methylcytosine in a promoter have on the expression of that gene?

Correct Answer
verified

What do you expect would develop if you injected Dnmt3 siRNA into honeybee larvae?

Correct Answer
verified

How long is Xist RNA?

Correct Answer
verified

Compare the effects of the environment on the epigenetics of glucocorticoid receptor expression in mice and humans.

Correct Answer
Answered by ExamLex AI
The effects of the environment on the ep...
View Answer

What type of enzyme would MOST likely promote increased gene expression?

Correct Answer
verified

When does paternal X inactivation occur in mice? (Select all that apply.)

Correct Answer
verified

Correct Answer
verified

Kit⁺Kit⁺ mice were crossed with Kit⁺Kit^t mice. The embryos resulting from this cross were then injected with miRNAs specific to Kit mRNA. What phenotype will these embryos develop to have?

Correct Answer
verified

Which of the following is NOT affected by genomic imprinting?

Correct Answer
verified

Describe three important features that define paramutation.

Which of the following statements is NOT true of DNA methylation?

Correct Answer
verified

Which of the following stimulates the transcription of Xist on the inactive X chromosome?

Correct Answer
verified

Which statement BEST described how imprinting varies over the course of development?

Correct Answer
verified
E

List three types of molecular mechanisms that alter chromatin structure and underlie many epigenetic phenotypes.

Correct Answer
Answered by ExamLex AI
Three types of molecular mechanisms that...
View Answer

Exam 21: Epigenetics

How does DNA methylation contribute to the repression of transcription?

Correct AnswerAnswered by ExamLex AIDNA methylation is an epigenetic mechani...View AnswerShow Answer

Which of the following is NOT a defining feature of paramutation?

Correct AnswerverifiedShow Answer

Which of the following stimulates the transcription of Xist on the active X chromosome?

Correct AnswerverifiedShow Answer

Explain how studies in mice suggest that diet can cause epigenetic changes that are transmitted through generations.

Correct AnswerAnswered by ExamLex AIStudies in mice have shown that diet can...View AnswerShow Answer

A group of scientists is studying memory in mice. They feed sodium butyrate, a histone deacetylase inhibitor, to a group of older mice and then subject them to memory exercises. How do you predict the memory of treated mice might compare with the memory of untreated mice?

Correct AnswerverifiedC

A beekeeper notices that her bee population is declining rapidly. Upon further study, she notices that there are no queen bees present in her population. She suspects this is due to exposure to an environmental agent. Which of the following could be a possible mechanism for the environmental agent?

Correct AnswerverifiedShow Answer

What effect would the deamination of 5-methylcytosine in a promoter have on the expression of that gene?

Correct AnswerverifiedShow Answer

What do you expect would develop if you injected Dnmt3 siRNA into honeybee larvae?

Correct AnswerverifiedShow Answer

How long is Xist RNA?

Correct AnswerverifiedShow Answer

Compare the effects of the environment on the epigenetics of glucocorticoid receptor expression in mice and humans.

Correct AnswerAnswered by ExamLex AIThe effects of the environment on the ep...View AnswerShow Answer

What type of enzyme would MOST likely promote increased gene expression?

Correct AnswerverifiedShow Answer

When does paternal X inactivation occur in mice? (Select all that apply.)

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Kit+Kit+ mice were crossed with Kit+Kitt mice. The embryos resulting from this cross were then injected with miRNAs specific to Kit mRNA. What phenotype will these embryos develop to have?

Correct AnswerverifiedShow Answer

Which of the following is NOT affected by genomic imprinting?

Correct AnswerverifiedShow Answer

Describe three important features that define paramutation.

Which of the following statements is NOT true of DNA methylation?

Correct AnswerverifiedShow Answer

Which of the following stimulates the transcription of Xist on the inactive X chromosome?

Correct AnswerverifiedShow Answer

Which statement BEST described how imprinting varies over the course of development?

Correct AnswerverifiedE

List three types of molecular mechanisms that alter chromatin structure and underlie many epigenetic phenotypes.

Correct AnswerAnswered by ExamLex AIThree types of molecular mechanisms that...View AnswerShow Answer

Correct Answer
Answered by ExamLex AI
DNA methylation is an epigenetic mechani...
View Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
Answered by ExamLex AI
Studies in mice have shown that diet can...
View Answer

Correct Answer
verified
C

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
Answered by ExamLex AI
The effects of the environment on the ep...
View Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Kit⁺Kit⁺ mice were crossed with Kit⁺Kit^t mice. The embryos resulting from this cross were then injected with miRNAs specific to Kit mRNA. What phenotype will these embryos develop to have?

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
E

Correct Answer
Answered by ExamLex AI
Three types of molecular mechanisms that...
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