Week 2: Epigenetics

Question 1

Covalent modifications of mammalian DNA occurring via the methylation of cytosine, typically
in the context of the CpG dinucleotide.

Answer 1

DNA Methylation

Question 2

Enzymes that establish and maintain DNA methylation using methyl-group donor compounds
or cofactors.

Answer 2

DNA Methyltransferases (DNMTs)

Question 3

The study of heritable changes in gene expression or cellular phenotype caused by
mechanisms other than changes in the underlying DNA sequence. Epigenetic marks include
covalent DNA modifications and posttranslational histone modifications.

Answer 3

Epigenetics

Question 4

The genome-wide distribution of epigenetic marks.

Answer 4

Epigenome

Question 5

A specific deoxyribonucleic acid (DNA) sequence that codes for a specific polypeptide or
protein or an observable inherited trait.

Answer 5

Gene

Question 6

A study that maps DNA polymorphisms in affected individuals and controls matched for age,
sex, and ethnic background with the aim of identifying causal genetic variants.

Answer 6

Genome-wide association study (GWAS)

Question 7

The DNA content of a cell’s nucleus, whether a trait is externally observable or not.

Answer 7

Genotype

Question 8

____ are enzymes that transfer acetyl groups to specific positions on histone tails, promoting
an “open” chromatin state and transcriptional activation. ____ remove these acetyl groups,
resulting in a “closed” chromatin state and transcriptional repression.

Answer 8

Histone acetyltransferases (HATs) and histone deacetylases (HDACs)

Question 9

Posttranslational modifications of the N-terminal “tails” of __________ proteins that serve as a
major mode of epigenetic regulation. These modifications include acetylation,
Epigenetics in Psychology 173
phosphorylation, methylation, sumoylation, ubiquitination, and ADP-ribosylation

Answer 9

Histone modifications

Question 10

Two individual organisms that originated from the same zygote and therefore are genetically
identical or very similar.

Answer 10

Identical twins

Question 11

The pattern of expression of the genotype or the magnitude or extent to which it is observably
expressed—an observable characteristic or trait of an organism, such as its morphology,
development, biochemical or physiological properties, or behavior.

Answer 11

Phenotype