Question 1

In terms of overall methylation,what is the most accurate way to describe the genomes of cancer cells?

Accepted Answer

Cancer cells generally exhibit global hypomethylation, which can lead to genomic instability, while also having hypermethylation at specific gene promoters.

Question 2

Different modification of the histone have different effects on gene expression.For instance,the ninth amino acid of histone 3 is a lysine H3K9)can be acetylated once or methylated up to three times.Which of the following is true regarding H3K9 modification?

Accepted Answer

The question states that if H3K9 is methylated up to three times, then the gene will be repressed. Therefore, if H3K9 has three methyl groups, the gene will be repressed. None of the other answer choices are supported by the information in the question.

Question 3

Long noncoding RNAs that partially overlap protein- coding genes and are transcribed in the opposite direction are best classified as________ .

Accepted Answer

Long noncoding RNAs (lncRNAs) that partially overlap protein-coding genes and are transcribed in the opposite direction are classified as antisense lncRNA genes. These lncRNAs can regulate gene expression by binding to the mRNA produced by the protein-coding gene and modulating its stability or translation.

Question 4

In terms of epigenetics,how the promoter would be described for a gene that is not expressed in lung tissue but is expressed in heart tissue?

Accepted Answer

In epigenetics, gene expression is often regulated by the methylation of cytosine bases in the promoter region of a gene. When the promoter is hypermethylated, the gene is typically not expressed because the methylation prevents the binding of transcription factors necessary for gene expression. Therefore, if a gene is not expressed in lung tissue but is expressed in heart tissue, it would be expected that the promoter's cytosines are hypermethylated in lung cells (silencing gene expression) and hypomethylated in heart cells (allowing gene expression).

Question 5

What is the name of the DNA region that controls the expression of a cluster of genes through methylation?

Accepted Answer

The DNA region that controls the expression of a cluster of genes through methylation is called an imprinting control region.

Question 6

Which of the following genotypes would most likely lead to a low birth weight and a small placenta?

Accepted Answer

The answer of Which of the following genotypes would most...

Question 7

The sum of histone modifications and their interactions is called the________ .

Accepted Answer

The sum of histone modifications and their interactions is referred to as the "histone code". This refers to the idea that specific combinations of histone modifications can influence gene expression and other cellular processes.

Question 8

Prader- Willi PW)and Angelman syndromes AS)are imprinting disorders of the same region on chromosome 15.Normally,the genes associated with PW are________ imprinted silenced ,and the one gene associated with AS is________ imprinted silenced .

Accepted Answer

Prader-Willi Syndrome (PWS) is caused by the loss of function of genes on the paternal chromosome 15 due to paternal imprinting (where the paternal genes are silenced), while Angelman Syndrome (AS) results from the loss of function of the UBE3A gene on the maternal chromosome 15 due to maternal imprinting (where the maternal gene is silenced).

Question 9

Which of the following statements is the most accurate in regards to mice pups who receive less maternal nurturing?

Accepted Answer

Mice pups that receive less maternal nurturing tend to have increased promoter methylation in their DNA, particularly in the glucocorticoid receptor gene. This epigenetic modification can lead to decreased expression of the glucocorticoid receptor, affecting the stress response system and making these mice less able to cope with stress as adults.

Question 10

Which DNA methyltransferase DNMT)is important in maintaining DNA methylation patterns during DNA replication?

Accepted Answer

DNMT1 is the DNA methyltransferase that is primarily responsible for maintaining DNA methylation patterns during DNA replication. It is able to recognize hemimethylated DNA (where only one strand is methylated) and restore the methylation on the newly synthesized strand. DNMT3a and DNMT3b are involved in de novo DNA methylation, where new methylation patterns are established, rather than maintaining existing patterns. DNMT2 has been shown to have tRNA methyltransferase activity, but not DNA methyltransferase activity. Therefore, the correct answer is choice A, DNMT1.

Question 11

In humans,the number of genes that are imprinted is less than 1%.These imprinted genes are usually associated with________ .

Accepted Answer

Imprinted genes are usually associated with growth regulation, meaning they play a role in controlling cell growth and division. This is important for proper development and differentiation of different tissues and organs in the body. While imprinted genes may also be involved in other processes such as metabolism or brain function, growth regulation is the primary function associated with imprinted genes.

Question 12

Compare and contrast DNMT1,DNMT3a,and DNMT3b in regards to what they do,when they act,and how they affect gene transcription.

Accepted Answer

The answer of Compare and contrast DNMT1,DNMT3a,and DNMT3b in regards...

Question 13

Which of the following is the most common place to find DNA methylation?

Accepted Answer

DNA methylation is most commonly found on cytosines when they are adjacent to guanines, occurring in the context of CpG dinucleotides. This pattern of methylation is frequently associated with gene silencing and has important implications in development and disease.

Question 14

A particular small noncoding RNA that is linked to spermatogenesis is most likely classified as what kind of noncoding RNA?

Accepted Answer

Piwi-interacting RNAs (piRNAs) are a class of small noncoding RNA molecules that are primarily expressed in animal cells and are known for their role in silencing transposons and other genetic elements in germ cells, particularly during spermatogenesis. They interact with Piwi proteins, a subset of the Argonaute family, to form RNA-protein complexes that are essential for the regulation of gene expression in the germ line.

Question 15

Which of the following statements is most true regarding X- inactivation?

Accepted Answer

X-inactivation is a process where one of the two X chromosomes in female mammals is inactivated to ensure dosage compensation between males (XY) and females (XX). This inactivation is stable and inherited through cell divisions, meaning that once an X chromosome is inactivated in a cell, it remains inactive in all of the cell's descendants.

Question 16

About 5% of those with Rubinstein- Taybi syndrome develops cancer as a result to decreased gene expression.This is directly linked to abnormal histone modification caused by a dysfunctional enzyme.What enzyme is this?

Accepted Answer

Histone acetyltransferase (HAT) is the enzyme linked to Rubinstein-Taybi syndrome through its role in histone modification. Mutations affecting HAT activity can lead to abnormal chromatin structure and gene expression, increasing cancer risk.

Question 17

All of the following are epigenetic mechanisms,EXCEPT ________ .

Accepted Answer

Mutation is not considered an epigenetic mechanism because it involves a change in the DNA sequence itself, rather than a modification of how the DNA is packaged or expressed. Epigenetic mechanisms involve changes in gene expression without changing the underlying DNA sequence.

Question 18

Which of the following is an example of genomic imprinting in humans?

Accepted Answer

Genomic imprinting refers to the differential expression of genetic material based on whether it was inherited from the mother or the father. In some cases, only the paternal or maternal allele is expressed, and this is an example of genomic imprinting. Option A refers to X-chromosome inactivation, which is not an example of genomic imprinting. Option B refers to random allelic expression, which is also not genomic imprinting. Option C is a normal sex chromosome complement and not an example of genomic imprinting. Option D refers to co-dominant expression of alleles, which is also not genomic imprinting.

Question 19

List the three major epigenetic mechanisms.

Accepted Answer

The answer of List the three major epigenetic mechanisms....

Question 20

________is the study of phenomena and mechanisms that cause chromosome- associated heritable changes to gene expression that are not dependent on changes in DNA sequence.

Accepted Answer

Epigenetics is the study of heritable changes in gene expression that are not attributable to changes in DNA sequence. Mutagenesis is the process of inducing mutations in DNA, transmission genetics deals with the passing of genetic information from one generation to the next, preformation is an outdated theory of development that posits that adult organisms are present in miniature form within the gametes, and population genetics is the study of how genetic variation is maintained and changes within populations over time.

Quiz 19: Epigenetic Regulation in Eukaryotes

In terms of overall methylation,what is the most accurate way to describe the genomes of cancer cells?

Different modification of the histone have different effects on gene expression.For instance,the ninth amino acid of histone 3 is a lysine H3K9) can be acetylated once or methylated up to three times.Which of the following is true regarding H3K9 modification?

Long noncoding RNAs that partially overlap protein- coding genes and are transcribed in the opposite direction are best classified as________ .

In terms of epigenetics,how the promoter would be described for a gene that is not expressed in lung tissue but is expressed in heart tissue?

What is the name of the DNA region that controls the expression of a cluster of genes through methylation?

Which of the following genotypes would most likely lead to a low birth weight and a small placenta?

The sum of histone modifications and their interactions is called the________ .

Prader- Willi PW) and Angelman syndromes AS) are imprinting disorders of the same region on chromosome 15.Normally,the genes associated with PW are imprinted silenced ,and the one gene associated with AS is imprinted silenced .

Which of the following statements is the most accurate in regards to mice pups who receive less maternal nurturing?

Which DNA methyltransferase DNMT) is important in maintaining DNA methylation patterns during DNA replication?

In humans,the number of genes that are imprinted is less than 1%.These imprinted genes are usually associated with________ .

Compare and contrast DNMT1,DNMT3a,and DNMT3b in regards to what they do,when they act,and how they affect gene transcription.

Which of the following is the most common place to find DNA methylation?

A particular small noncoding RNA that is linked to spermatogenesis is most likely classified as what kind of noncoding RNA?

Which of the following statements is most true regarding X- inactivation?

About 5% of those with Rubinstein- Taybi syndrome develops cancer as a result to decreased gene expression.This is directly linked to abnormal histone modification caused by a dysfunctional enzyme.What enzyme is this?

All of the following are epigenetic mechanisms,EXCEPT ________ .

Which of the following is an example of genomic imprinting in humans?

List the three major epigenetic mechanisms.

________is the study of phenomena and mechanisms that cause chromosome- associated heritable changes to gene expression that are not dependent on changes in DNA sequence.

Quiz 19: Epigenetic Regulation in Eukaryotes

In terms of overall methylation,what is the most accurate way to describe the genomes of cancer cells?

Different modification of the histone have different effects on gene expression.For instance,the ninth amino acid of histone 3 is a lysine H3K9) can be acetylated once or methylated up to three times.Which of the following is true regarding H3K9 modification?

Long noncoding RNAs that partially overlap protein- coding genes and are transcribed in the opposite direction are best classified as________ .

In terms of epigenetics,how the promoter would be described for a gene that is not expressed in lung tissue but is expressed in heart tissue?

What is the name of the DNA region that controls the expression of a cluster of genes through methylation?

Which of the following genotypes would most likely lead to a low birth weight and a small placenta?

The sum of histone modifications and their interactions is called the________ .

Prader- Willi PW) and Angelman syndromes AS) are imprinting disorders of the same region on chromosome 15.Normally,the genes associated with PW are________ imprinted silenced ,and the one gene associated with AS is________ imprinted silenced .

Which of the following statements is the most accurate in regards to mice pups who receive less maternal nurturing?

Which DNA methyltransferase DNMT) is important in maintaining DNA methylation patterns during DNA replication?

In humans,the number of genes that are imprinted is less than 1%.These imprinted genes are usually associated with________ .

Compare and contrast DNMT1,DNMT3a,and DNMT3b in regards to what they do,when they act,and how they affect gene transcription.

Which of the following is the most common place to find DNA methylation?

A particular small noncoding RNA that is linked to spermatogenesis is most likely classified as what kind of noncoding RNA?

Which of the following statements is most true regarding X- inactivation?

About 5% of those with Rubinstein- Taybi syndrome develops cancer as a result to decreased gene expression.This is directly linked to abnormal histone modification caused by a dysfunctional enzyme.What enzyme is this?

All of the following are epigenetic mechanisms,EXCEPT ________ .

Which of the following is an example of genomic imprinting in humans?

List the three major epigenetic mechanisms.

________is the study of phenomena and mechanisms that cause chromosome- associated heritable changes to gene expression that are not dependent on changes in DNA sequence.

Prader- Willi PW) and Angelman syndromes AS) are imprinting disorders of the same region on chromosome 15.Normally,the genes associated with PW are imprinted silenced ,and the one gene associated with AS is imprinted silenced .