Exam 2 Chapter 16
True or false: Because epigenetics refers to heritable changes in gene expression, all epigenetic changes are examples of transgenerational epigenetic inheritance. True false question. True False
False
To promote a closer association of nucleosomes, heterochromatin protein 1 (HP1) recognizes the histone modification found in ______. Multiple choice question. cenH3 H3K9me3 H3.3 H3K27me3
H3K9me3
When binding to chromatin, where would a dimer of heterochromatin protein 1 (HP1) be found?
In the linker region between nucleosomes
Which of the following are features associated with facultative heterochromatin?
Methylation at CpG islands located in the regulatory regions of genes In animals, contain LINE-type repeated sequences Trimethylation of histone H3 at the 9th or 27th lysine Located at multiple discrete sites between the centromere and telomeres
Which of the following is an example of epigenetic inheritance? Multiple choice question. Methylation of DNA that occurs in an oocyte A modified histone in a stem cell A chromatin modification that causes cancer in a lung cell Mutation of DNA in a sperm cell
Methylation of DNA that occurs in an oocyte
Which molecular processes will enhance the formation of higher-order structure in heterochromatin?
Posttranslational modifications of histones Binding of proteins to nucleosomes DNA methylation
Which of the following represent key functional roles for heterochromatin in eukaryotic cells?
Preventing movement of transposable elements Silencing genes Preventing viral proliferation
Which of the following statements regarding X chromosome inactivation is true?
X chromosome inactivation occurs during embryogenesis in females.
An area of the chromosome that protects a euchromatic region from spreading of adjacent heterochromatin is called a(n) ......
barrier
An area of the chromosome that protects a euchromatic region from spreading of adjacent heterochromatin is called a(n) .......
barrier
Which component can prevent heterochromatin spreading into an adjacent euchromatic region of the chromosome? Multiple choice question. silencer presence of nucleosomes enhancer barrier
barrier
Once heterochromatin protein 1 (HP1) forms a dimer in the linker region between nucleosomes, which types of proteins does it recruit to the site?
chromatin-remodeling complexes chromatin-modifying enzymes
Regions of heterochromatin that vary among different cell types are called ....... heterochromatin.
facultative
A protein that forms a dimer in the linker region between nucleosomes carrying the modified histone H3K9me3 is ______. Multiple choice question. heterochromatin protein 1 (HP1) CCCTC-binding factor (CTCF) euchromatin protein 1 (EU1) histone H1
heterochromatin protein 1 (HP1)
Two nucleosomes with modified histone H3K9me3 can be brought closer together through the formation of a dimer involving ______.
heterochromatin protein 1 (HP1)
In most eukaryotic cells, the inner nuclear membrane of the cell is lined by a fibrous layer of proteins called the nuclear ......
lamina
A heterochromatic region with fully methylated DNA and extensively modified histone H3 prior to DNA replication, will have ______ (the) levels of these modifications in the daughter chromatids produced after DNA replication. Multiple choice question. the same 1/2 1/4
1/2
Which of the following represents a higher-order structure found in chromatin? Multiple choice question. DNA double helix 30-nm fiber histone octamer extended chain of nucleosomes nucleosome
30-nm fiber
Which of the following are examples of epigenetics?
DNA methylation Chromatin remodeling Covalent histone modification Localization of histone variants
Which of the following are true regarding epigenetics?
Epigenetic changes may be transmitted to offspring Variations of gene expression are unrelated to variations in the DNA base sequence Variations are reversible from one generation to the next Epigenetic changes are transmissible from cell to cell
Idenfity the diseases that have been associated with abnormalities in heterochromatin formation. Multiple select question. Roberts syndrome Cri-du-chat syndrome Cancer ICF syndrome
Roberts syndrome ICF syndrome
In heterochromatin formation, which of the following are responsible for recruiting histone deacetylases and histone methyltransferases to a nucleation site?
Sequence-specific DNA-binding proteins Non-coding RNAs
Which of the following are features associated with constitutive heterochromatin in yeast and animal cells?
Trimethylation of a lysine at the ninth position in histone H3 Located at telomeres and close to centromeres Composed of many, short tandemly repeated sequences DNA is highly methylated on cytosines
Once heterochromatin protein 1 (HP1) forms a dimer in the linker region between nucleosomes, which types of proteins does it recruit to the site? Multiple select question. chromatin-modifying enzymes chromatin-remodeling complexes histones with posttranslational modifications RNA polymerases
chromatin-modifying enzymes chromatin-remodeling complexes
Lamina-associated domains (LADs) are regions of ______ found in close contact with the nuclear lamina in eukaryotic cells.
chromosomes
Identify proteins involved in forming loop domains in heterochromatin. Multiple select question. condensin CCCTC-binding protein histone H1 H3K9me3 heterochromatin protein 1 (HP1)
condensin CCCTC-binding protein
Regions of heterochromatin that are seen in the same location in all cell types are called ....... heterochromatin.
constitutive
Regions of the chromatin containing numerous, short, tandemly repeated sequences that are located near the centromeres and at the telomeres of eukaryotic chromosomes are called ______ heterochromatin. Multiple choice question. constitutive activated facultative euchromatic
constitutive
A series of genetically programmed stages that begins with sperm and eggs that fuse to become an embryo that will eventually change into an adult is called ______. Multiple choice question. cellular division development growth
development
Chromosomal regions that are in close contact with the nuclear lamina are called lamina-associated .......
domains
DNA methylation, chromatin remodeling, covalent histone modification, and localization of histone variants are all examples of molecular mechanisms that are involved in ......
epigenetics
DNA methylation, chromatin remodeling, covalent histone modification, and localization of histone variants are all examples of molecular mechanisms that are involved in .......
epigenetics
The variation of gene expression that is not related to the variation of the DNA, is transmissible, and is reversible is described as ......
epigenetics
The variation of gene expression that is not related to the variation of the DNA, is transmissible, and is reversible is described as .......
epigenetics
Higher-order heterochromatin structure is characterized by ______.
formation of loop domains closer contacts between nucleosomes binding of heterochromatin to the nuclear lamina
An RNA that does not encode a polypeptide is a(n) ______ RNA. Multiple choice question. immature secondary non-coding structural
non-coding
An RNA that does not encode a polypeptide is a(n) ______ RNA. Multiple choice question. secondary immature structural non-coding
non-coding
Besides DNA and histone proteins, ........ - ....... RNAs are a critical component of chromatin.
non-coding
Which components can initiate heterochromatin formation at a nucleation site? Multiple select question. H3K9me3 chromatin-modifying proteins CCCTC-binding factors (CTCFs) non-coding RNA sequence-specific DNA binding proteins
non-coding RNA sequence-specific DNA binding proteins
A fibrous layer of proteins lining the inner nuclear membrane of eukaryotic cells is called the ______. Multiple choice question. nuclear lamina nucleolus nuclear envelope nuclear matrix
nuclear lamina
The formation of heterochromatin begins at a site, continues by in both directions, and stops when a site is reached.
Blank 1: nucleation Blank 2: spreading Blank 3: barrier
The basic repeating unit of chromatin is the ....... , composed of ....... wrapped around an octamer of ....... proteins.
Blank 1: nucleosome Blank 2: DNA Blank 3: histone
Characteristics of higher-order heterochromatin structure include closer contact between ....... , formation of ....... domains and binding of heterochromatin to the nuclear ......
Blank 1: nucleosomes Blank 2: loop Blank 3: lamina
Heterochromatin protein 1 (HP1) causes changes in heterochromatin structure when HP1 dimers ...... chromatin-modifying enzymes and chromatin-remodeling complexes to the site of dimer binding.
Blank 1: recruit
If an epigenetic change is maintained only at a given site and does not affect the expression of a gene elsewhere in the nucleus, it is a ______ mechanism. Multiple choice question. cis-epigenetic trans-epigenetic
cis-epigenetic
Which type of epigenetic mechanism is shown in the image? Multiple choice question. cis-epigenetic mechanism trans-epigenetic mechanism
cis-epigenetic mechanism
The role of heterochromatin in repressing transcription may be due to interference with which of the following factors? Multiple select question. coactivators RNA polymerase II transcriptional activators general transcription factors
coactivators transcriptional activators general transcription factors
Heterochromatic regions found at multiple discrete sites located between the centromeres and telomeres which show with methylated DNA at CpG islands in regulatory regions are called ______ heterochromatin. Multiple choice question. activated constitutive facultative euchromatic
facultative
Before replication, a heterochromatic region has sites with fully methylated DNA and nucleosomes with H3K9me3 histone modifications. After DNA replication, what would be the constituents of each daughter chromatid?
hemimetylated DNA half of the H3 histones with H3K9me3 modifications
Before replication, a heterochromatic region has sites with fully methylated DNA and nucleosomes with H3K9me3 histone modifications. After DNA replication, what would be the constituents of each daughter chromatid? Multiple select question. hemimetylated DNA half of the H3 histones with H3K9me3 modifications all of the H3 histones with H3K9me3 modifications fully methylated DNA
hemimetylated DNA half of the H3 histones with H3K9me3 modifications
ICF syndrome and Roberts syndrome are inherited diseases associated with abnormalities in ______.
heterochromatin formation
In most eukaryotic cells, the inner nuclear membrane of the cell is lined by a fibrous layer of proteins called the nuclear .......
lamina
Condensin and CCCTC-binding factor (CTCF) are involved in forming ....... domains in heterochromatin
loop
Condensin and CCCTC-binding factor (CTCF) are involved in forming ....... domains in heterochromatin.
loop
Genes that are expressed but do not encode polypeptides produce ....... - ...... RNAs.
non coding
In eukaryotic cells, which processes are prevented by heterochromatin? Multiple select question. viral proliferation translation transposable element movement transcription DNA replication
viral proliferation transposable element movement transcription
Any assemblage of nucleosomes that assumes a reproducible confirmation in three-dimensional space represents a - ........ structure.
Blank 1: higher Blank 2: order
Formation of higher-order structures in heterochromatin depends upon posttranslational modifications of ......., binding of proteins to ......., and DNA. ........
Blank 1: histones Blank 2: nucleosomes Blank 3: methylation
The formation of heterochromatin begins at a ....... site, continues by ....... in both directions, and stops when a ....... site is reached.
Blank 1: nucleation Blank 2: spreading Blank 3: barrier
During cell division, from M phase in the mother cell to interphase in the resulting two daughter cells, a chromosome will usually retain the same pattern of ........ and ........ heterochromatin that was found in the mother cell.
Blank 1: constitutive Blank 2: facultative
Regions of a protein that catalyze the addition of posttranslational modifications (PTMs) are called ...... domains.
writer
Which of the following are examples of epigenetics? Multiple select question. DNA methylation Covalent histone modification DNA mutation Localization of histone variants Chromatin remodeling DNA translocation
DNA methylation Covalent histone modification Localization of histone variants Chromatin remodeling
Identify ways that heterochromatin can inhibit transcription.
Inhibiting the recruitment of general transcription factors or coactivators Preventing activators from binding to enhancer sequences
Lamina-associated domains (LADs) are regions of ______ found in close contact with the nuclear lamina in eukaryotic cells. Multiple choice question. chromatin-remodeling complexes chromatin-modifying enzymes replicating enzymes chromosomes
chromosomes
Genomic imprinting and X-chromosome inactivation are examples of ______ mechanisms that occur during development. Multiple choice question. trans-epigenetic cis-epigenetic
cis-epigenetic
Regions of a protein that control the binding of particular proteins to nucleosomes with posttranslational modifications (PTMs) are called ______ domains. Multiple choice question. reader eraser writer sensor
reader
In eukaryotic cells, which processes are prevented by heterochromatin? Multiple select question. transcription DNA replication viral proliferation transposable element movement translation
transcription viral proliferation transposable element movement