Epigenetic Modifications: Types and Mechanisms

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What happens to epigenetic imprints during meiosis in germ cells?

They are erased and new ones are set based on the sex of the organism (correct)

They are maintained throughout the lifespan

They are only partially reset

They are not affected during meiosis

What is the effect of methylation at imprinting control regions (ICRs) on gene expression?

It can turn the genes on or off depending on the ICR and gene configuration (correct)

It has no effect on gene expression

It always turns the genes off

It always turns the genes on

What is the effect of small deletions in the chromosome 15; q11-13 region on gene imprinting?

Both genes are silenced

Both genes are active

The genes are imprinted randomly

At least two genes are differently imprinted (correct)

What is the result of a non-methylated maternal insulator in the Igf2 gene?

Transcription is silenced Signup and view all the answers

What is the role of CpG islands in the ncRNA mechanism of imprinting?

They allow the production of ncRNA Signup and view all the answers

What is the purpose of the epigenetic phenomenon that helps differentiated cells maintain their fates through cell divisions?

To maintain cellular identity Signup and view all the answers

Which syndrome occurs when the deletion is inherited from the father?

Prader-Willi syndrome Signup and view all the answers

How many imprinted genes have been identified by RNA-Seq?

About 100 Signup and view all the answers

How is the memory of constitutive heterochromatin transmitted through cell divisions?

Through epigenetic modification Signup and view all the answers

What is the result of a methylated paternal insulator in the Igf2 gene?

Transcription is active Signup and view all the answers

What is the role of the inactive X chromosome in the somatic cells of mammalian females?

To maintain cellular identity Signup and view all the answers

What is the mechanism of imprinting in which an ICR contains a noncoding RNA?

ncRNA mechanism Signup and view all the answers

What is the primary effect of DNA methylation on gene expression?

Gene silencing Signup and view all the answers

What is the role of DNA methyltransferases (DNMTs) in DNA methylation?

Adding methyl groups to DNA Signup and view all the answers

What happens to the cytosine methylation pattern during DNA replication?

It is copied Signup and view all the answers

What is the consequence of DNA methylation on transcription factors?

They are prevented from accessing DNA Signup and view all the answers

What is the result of DNA methylation on gene regulation?

Gene repression and silencing Signup and view all the answers

What is the significance of DNA methylation in cell division?

It is a long-term modification Signup and view all the answers

What is the mechanism by which cells 'remember' their fate from cell generation to cell generation?

Histone modifications Signup and view all the answers

Which of the following is an example of epigenetic phenomena where genes transmit information about their silenced state to subsequent cells?

Imprinting Signup and view all the answers

What is the role of the master regulator in determining cell fate?

To determine gene expression and potential fates Signup and view all the answers

What is the function of the Polycomb response element (PRE) in Hox gene repression?

To bind repressors and recruit the PRC2 co-repressor complex Signup and view all the answers

What is the result of the PRC2 complex methylating lysine 27 in histone H3?

Repression of Hox gene expression Signup and view all the answers

What is the role of Hox genes in Drosophila development?

To set up the animal's segmented body plan Signup and view all the answers

What is the role of PRC2 binding to the PRE in maintaining silencing at Hox genes?

It is required for maintaining silencing but not necessary for initiating silencing. Signup and view all the answers

What type of chromatin is found at centromeres and is important for preventing transposable element mobilization?

Constitutive heterochromatin Signup and view all the answers

What is the type of epigenetic inheritance that occurs when epigenetic information is transmitted from one generation to the next?

Intergenerational inheritance Signup and view all the answers

What is the process by which the environment can alter epigenetic information that is subsequently transmitted intergenerationally?

Epigenetic adaptation Signup and view all the answers

What is the gene that is an example of epigenetic inheritance in mice?

Agouti gene Signup and view all the answers

Can a trait acquired by a multicellular organism through environmental influences be passed on to its progeny?

Yes, it is possible through epigenetic inheritance. Signup and view all the answers