epigenetics - exam 2

Question 1

epigenetics

Answer 1

any process that alters gene activity w/out changing the DNA sequence

reversible – addition or subtraction of methyl groups

Question 2

methylation

Answer 2

addition of CH3

hyper-methylation can silence genes

Question 3

heterochromatin

Answer 3

DNA packed so tightly

genes not expressed

hidden from transcription

Question 4

euchromatin

Answer 4

DNA packed less tightly

gene expressed

available for transcription

Question 5

Barr body

Answer 5

chromosome is so condensed that the genes cannot be expressed

Question 6

x inactivation

Answer 6

x in each cell randomly inactivated

Question 7

turner syndrome

Answer 7

not fully condensed barr body that expresses some genes

same gene on x chromosomes are needed in a double dose

Question 8

what happens when pregnant agouti mice are treated w/ methylating agents

Answer 8

mothers given the supplement gave birth to darker pups that were less prone to obesity & diabetes

different expression of same agouti gene

Question 9

how do identical twins, who have identical genomes have different phenotypes

Answer 9

the environment shapes different epigenomes

Question 10

findings of epigenetic twin studies

Answer 10

schizophrenia

obesity

rheumatoid arthritis

influence of smoking & alc use on bones

effects of social class & exercise on aging

causality of c-reactive protein in heart disease & obesity

Question 11

exposure sensitive period for grandmothers

Answer 11

in the womb

Question 12

exposure sensitive period for grandfathers

Answer 12

puberty

Question 13

can epigenetic tags be passed between generatios

Answer 13

variation in food supply of paternal grandparents was related to variation in mortality rate in their grandchildren