Chapter 16 - Gene Regulation in Eukaryotes II: Epigenetics

Question 1

The study of mechanisms that lead to change in gene expression that are passed from cell to cell and are reversible but don not involve a change in the DNA sequence

Answer 1

Epigenetics

Question 2

Examples of epigenetics

Answer 2

X-chromosome inactivation and genomic imprinting

Question 3

Types of molecular changes that underlie epigenetic regulation

Answer 3

DNA methylation, chromatin remodeling, histone modification, localization of histone variants, feedback loops

Question 4

Epigenetic changes that are maintained at a specific site

Answer 4

Cis changes

Question 5

Epigenetic changes that are maintained by diffusible factors

Answer 5

Trans changes

Question 6

How can Cis and Trans changes be observed?

Answer 6

Cell fusion experiments

Question 7

What are the two categories of epigenetic gene regulation?

Answer 7

Programmed developmental change and environmental agents of change

Question 8

Regions of chromatin that are not stained during interphase, transcriptionally active, and occupy a central position in the nucleus

Answer 8

Euchromatin

Question 9

Regions of chromatin that are stained throughout the cell cycle, have a high level of compaction, inhibit gene expression, and are localized along the periphery of the nucleus

Answer 9

Heterochromatin

Question 10

Roles of heterochromatin

Answer 10

Gene silencing, prevention of transposable element movement, and prevention of viral proliferation

Question 11

Heterochromatin that is heterochromatic at the same location in all cell types

Answer 11

Constitutive heterochromatin

Question 12

Heterochromatin that is heterochromatic at varying locations among different cell types

Answer 12

Facultative heterochromatin

Question 13

The addition of PTMs

Answer 13

Writer domains

Question 14

The removal of PTMs

Answer 14

Eraser domains

Question 15

Phases of formation of facultative and constitutive chromatin

Answer 15

Nucleation, spreading, and barrier

Question 16

How can abnormalities in heterochromatin formation affect humans?

Answer 16

Diseases like ICF and Roberts syndrome

Question 17

Much of development is regulated by epigenetic regulation, true or false

Answer 17

True

Question 18

A form of gene regulation in which an offspring expresses the copy of a gene from one parent but not both

Answer 18

Genomic imprinting

Question 19

Trithorax group (TrG)

Answer 19

involved with gene activation

Question 20

Polycomb group (PcG)

Answer 20

involved with gene repression

Question 21

PRC1 may inhibit transcription in three different ways

Answer 21

Chromatin compaction, covalent modification of histones, direct interaction with a transcription factor

Question 22

Allele with the capacity to induce changes in others at a single locus

Answer 22

Paramutagenic

Question 23

Allele that has been altered by another allele at the same locus

Answer 23

Paramutable

Question 24

Effects of paramutation variation

Answer 24

The likelihood that the paramutagenic allele will alter the paramutable allele, and the stability of the paramutagenic allele over generations

Question 25

Epigenetic changes that are transmitted from parent to offspring are called...

Answer 25

Paramutations

Question 26

Can the environment cause epigenetic changes?

Answer 26

Yes

Question 27

Honeybee example

Answer 27

Bees that eat royal jelly into adulthood become queens later in life