Ch.16: Gene regulation in eukaryotes II: Epigenetics

Question 1

Epigenetic Change

Answer 1

a change in gene expression that is permanent over the course of an individual’s life, but not over the course of multiple generations- don’t involve changes to the sequence of an individual’s DNA; primarily caused by DNA methylation, histone modification or chromatin remodeling

Question 2

Epigenetic Inheritance

Answer 2

involves epigenetic changes that are passed from parent to offspring, such as genomic imprinting

Question 3

Euchromatin

Answer 3

regions that are not stained during interphase; Transcriptionally active

Question 4

Heterochromatin

Answer 4

regions that are stained throughout the cell cycle (more compact than euchromatin); not transcriptionally active

Question 5

What changes are maintained by epigenetic regulation?

Answer 5

-Genomic imprinting
-X-chromosome inactivation
-Formation of specific cell types and tissues

Question 6

What results in an active X chromosome?

Answer 6

expression of Tsix RNA

Question 7

What results in an inactive X chromosome?

Answer 7

expression of Xist RNA allows it to become a Barr body

Question 8

What are competing protein complexes? Name the 2 types

Answer 8

they are both key regulators
of epigenetic changes that occur during development and
produce specific cell types and tissues
- Trithorax group (TrxG)- involved with gene activation
- Polycomb group (PcG)- involved with gene repression

Question 9

Paramutation

Answer 9

the interaction between two alleles at a single locus where one allele induces a
change in the other allele
-Allele that has this capacity is paramutagenic
-Allele that has been altered is paramutable