Epigenomics: Gene Expression and the Microenvironment

Question 1

The _____ uses chemicals that affect the structure or that silence parts of the genome.

Answer 1

epigenome

Question 2

The chemical modifications of the epigenome _____ with the parental DNA, and can be passed on from generation to generation.

Answer 2

stay

Question 3

The epigenome chemical modifications can be altered by interactions with the _____, including things such as parental diet and exposure to toxins.

Answer 3

environment

Question 4

_____ is the addition of a chemical tag called a methyl group to the DNA sequence itself. This can turn gene expression on or off.

Answer 4

Methylation

Question 5

Some genes are expressed only if they are transmitted from the father, and some are expressed only if they are from the mother. The chemical process of _____ silences the genes from one parent. If a gene with a defect is the only active gene or if there is a deletion and the needed gene is not there, disease will result.

Answer 5

methylation

Question 6

The DNA double helix winds around _____ proteins, which give it structure and stability, allowing the DNA to form chromosomes.

Answer 6

histone

Question 7

_____ (or chromatin) modification involves changes to the proteins around which the DNA double helix winds.

Answer 7

Histone

Question 8

In _____ modification, chemical tags attach to the “tails” of the histones and can alter how tightly the DNA is packaged by adjusting the tension with which it winds. When wound tightly, some sequences of DNA may not be available and thus “turned off”. When loosened, a hidden gene may be “turned on”.

Answer 8

histone

Question 9

_____ modification and DNA _____ can turn gene expression on and off.

Answer 9

1. Histone

2. methylation

Question 10

_____ are small single-stander pieces of RNA that can bind to messenger RNA, making it double-stranded and preventing protein production.

Answer 10

MicroRNAs

Question 11

_____ are only 20-30 bases long, and they do not encode _____.

Answer 11

1. MicroRNA

2. protein

Question 12

_____ _____ is the ability of the environment to cause different phenotypes from the same genotype.

Answer 12

Developmental plasticity

Question 13

_____ changes have been implicated in the onset of autoimmune diseases such as SLE.

Answer 13

Epigenomic

Question 14

DNA _____ may result in the silencing of tumor-suppressor genes or the activation of oncogenes.

Answer 14

methylation

Question 15

_____ changes are maintained through mitosis and are passed on in the germ line during meiosis.

Answer 15

Epigenetic