Comprehension Questions

Introduction

Question 21.1

What is the thrifty phenotype hypothesis? How does it help to explain the long-term effects of diet that were observed among the residents of Överkalix?

Section 21.1

Question 21.2

What are the important characteristics of an epigenetic trait?

Section 21.2

Question 21.3

What three molecular mechanisms alter chromatin structure and are responsible for many epigenetic phenotypes?

Question 21.4

What is the major form of DNA methylation that is seen in eukaryotes? At what type of DNA sequence is DNA methylation usually found?

Question 21.5

How does DNA methylation repress transcription?

Question 21.6

Briefly explain how patterns of DNA methylation are transmitted across cell division.

Question 21.7

What types of histone modifications are responsible for epigenetic phenotypes?

Section 21.3

Question 21.8

What is paramutation? What are the key features of this phenomenon?

Question 21.9

Briefly describe paramutation at the Kit locus in mice. What evidence suggests that small RNA molecules play a role in this phenomenon?

Question 21.10

What evidence suggests that cognition in mice is influenced by epigenetic changes?

Question 21.11

Explain how vinclozolin acts as an endocrine disrupter.

Question 21.12

Give an example of a transgenerational epigenetic effect of diet on metabolism.

Question 21.13

What evidence suggests that differences in monozygotic twins may be caused by epigenetic effects?

Question 21.14

How is X inactivation an epigenetic phenotype?

Question 21.15

Briefly describe the molecular processes that cause one X chromosome in each female cell to be active and the other X chromosome to become inactivated.

Question 21.16

What are induced pluripotent stem cells? How are they derived from adult somatic cells?

Question 21.17

Define genomic imprinting.

Question 21.18

What is the genomic conflict hypothesis for the origin of genomic imprinting?

Section 21.4

Question 21.19

What is the epigenome?

For more questions that test your comprehension of the key chapter concepts, go to for this chapter.