Chapter 3

Question 1

Epigenetics vs. Genetics

Answer 1

Epigenetics: environmental risks (AKA social determinants of health)

Genetics: inherited risk for illness onset

Question 2

what is DNA methylation

Answer 2

a chemical reaction of methyl molecule group gets added to DNA proteins. methylation can turn off gene expression.

Question 3

Risk factors for common genetic disease

Answer 3

-Family history of a genetic disorder.
-Prior child with a genetic disorder.
-One parent has a chromosomal abnormality.
-Advanced maternal age (35 or older)
-Advanced paternal age (40 or older)
-Multiple miscarriages or prior stillbirth.

Question 4

define Genetic/genomic imprinting and give examples

Answer 4

a given gene is transcriptionally inactive on only one copy of a chromosome

Copy inherited from father is active while copy inherited from mother is inactive (silenced)

Transcriptionally silenced genes are said to be “imprinted”

Ex: Prader-Willi and Angelman syndromes
○ Manifestations of Prader-Willi syndrome if inherited from father
§ Short stature, hypotonia, small hands and feet, obesity, mentally challenged
○ Manifestations of Angelman syndrome if inherited from mother
§ Severely mentally challenged, seizures, ataxic gait

Question 5

The epigenetic mechanism with a known relationship to a certain type of cancer is

a. histone modifications
b. RNA-based modifications
c. abnormal DNA methylation

Answer 5

c. abnormal DNA methylation

Question 6

genomic imprinting is best described as

A. epigenetic modifications caused by environmental factors
B. The heritable transmission to future generations of epigenetic modifications
C. Genes are silenced depending on which parent transmits them
D. Phenotype is the same whether a given allele is inherited from the mother or the father

Answer 6

C. Genes are silenced depending on which parent transmits them

Question 7

Angelman is a genetic condition inherited from the father and occurs primarily in males.

A. True
B. False

Answer 7

B. False

Question 8

_______ occurs when a methyl group is attached to a cytosine, rendering the gene inactive

a. DNA methylation
b. histone modification
c. RNA-based alteration

Answer 8

a. DNA methylation

Question 9

_________ is the study of mechanisms that will switch genes “on”, such that they are expressed, and “off” such that they are silenced.

a. epigenetics
b. endocrinology
c. hematology
d. rheumatology

Answer 9

a. epigenetics

Question 10

examples of genetic _________ include Prader-Willi and Angelman syndromes

a. biallelic inheritance
b. monoallelic inheritance
c. imprinting

Answer 10

c. imprinting