In the process of genomic imprinting, when are the parent-specific epigenetic marks reset?

Correct answer: During gametogenesis (the formation of eggs or sperm).

Explanation

This question assesses understanding of the dynamic nature of genomic imprinting and when the critical resetting of marks occurs.

Other questions

Question 1

According to the introduction, Jean Baptiste Lamarck's theory of evolution proposed that individuals within a population vary because of what?

Question 2

What is the structure of the nucleosome core, which is the basic unit of chromatin?

Question 3

Approximately how many base pairs of DNA are wrapped around the histone octamer to form a nucleosome core?

Question 4

What is the general effect of histone acetylation on chromatin structure and gene expression?

Question 5

Which class of enzymes is responsible for removing acetyl groups from histone tails?

Question 6

In contrast to histone acetylation, what is the effect of methylating histone H3 at position K9 (lysine 9)?

Question 7

Where does DNA methylation typically occur in the genome, and what is the resulting sequence called?

Question 8

What is the general association between DNA methylation and transcription?

Question 9

What term describes the ability of a cell, such as in a very early embryo, to divide and give rise to any other cell type?

Question 10

In individuals with more than one X chromosome, the transcriptionally inactive, condensed X chromosome is visible as what structure?

Question 11

What is the defining characteristic of imprinted genes?

Question 12

Angelman syndrome is associated with a loss of function in the maternal copy of the UBE3A gene on Chromosome 15. Why does a mutation in the paternal allele not cause the syndrome?

Question 13

What has been observed about the epigenomes of identical twins over their lifetime?

Question 14

According to the text, a study of the plant Arabidopsis thaliana showed that induced DNA methylation could be measured for how many generations of offspring?

Question 15

Exposure to which synthetic estrogen during pregnancy in the 1940s-1960s has been linked to transgenerational health effects in children and grandchildren?

Question 16

To demonstrate true transgenerational epigenetic inheritance through meiosis, what is the minimum group of descendants that must be tracked from an exposed pregnant parent?

Question 17

The histone octamer at the core of a nucleosome is composed of two copies each of which four histone proteins?

Question 18

What is the collective term for the combination of all epigenetic marks found in a cell?

Question 19

What is the primary characteristic of heterochromatin?

Question 20

Which enzymes catalyze the transfer of one or more methyl groups to selected lysine or arginine side chains in histone tails?

Question 21

What term is used for DNA that is methylated on only one of the two strands immediately after replication?

Question 22

Which long non-coding RNA molecule is essential for the process of X-chromosome inactivation?

Question 23

What is the term for a situation where more than 75 percent of cells in an XX individual inactivate the X chromosome inherited from the same parent?

Question 24

Beckwith-Wiedemann syndrome, characterized by larger-than-average size, is caused by a disruption in imprinted genes on which human chromosome?

Question 25

According to the text, approximately what percentage of human genes are estimated to be imprinted?

Question 26

What is the role of chromatin remodelers?

Question 27

The text describes the ends of histone polypeptides that stick out from the nucleosome core as histone tails. These tails are over-represented in which type of amino acids?

Question 28

Nutrients such as folate, choline, and S-adenosyl methionine (SAMe) are important for epigenetics primarily because they are sources or donors of what?

Question 29

The methylation of which gene is mentioned as being linked to the development of schizophrenia, potentially explaining its incomplete penetrance?

Question 30

How are histone modifications maintained on daughter DNA strands after replication?

Question 31

In the case of paternal imprinting, which allele is silenced?

Question 32

The development of a calico cat's patchwork fur is a visually striking example of what epigenetic phenomenon?

Question 33

What is the function of the enzymes called histone acetyl transferases (HATs)?

Question 34

The text mentions that curcumin, found in turmeric, affects the epigenome by doing what?

Question 35

The 'tail kink' phenotype in mice is associated with a mutation in the AxinFu gene, but its penetrance depends on what epigenetic factor?

Question 36

Which of the following is an example of an epigenetic mark?

Question 37

What is the key difference between pluripotent and totipotent stem cells as described in the chapter?

Question 38

Loss-of-function of tumor suppressor genes can be caused by mutations or by what epigenetic modification?

Question 39

What type of enzyme adds a methyl group to cytosine bases in DNA?

Question 41

Which statement best describes the relationship between the histone code and the epigenome?

Question 42

Which epigenetic mechanism is most directly responsible for the different fur color patches on a calico cat?

Question 43

A key difference between histone acetylation and histone methylation is that:

Question 44

The genes Nanog and Oct-4 are epigenetically regulated during early development. What is their status in embryonic stem cells versus trophoblast cells?

Question 45

What is the primary reason that epigenetic inheritance, such as the inheritance of acquired traits, is not considered a typical Mendelian inheritance pattern?

Question 46

The maintenance of DNA methylation after replication relies on enzymes recognizing what feature of the newly synthesized DNA?

Question 47

According to the text, what is the impact of skewed X-inactivation on females heterozygous for X-linked diseases like Hemophilia B?

Question 48

What type of macromolecule is S-adenosyl methionine (SAM or SAMe)?

Question 49

Which of the following describes the difference between euchromatin and heterochromatin?

Question 50

What is the primary role of histone tails in chromatin dynamics?