epigenetics

Question 1

what is it

Answer 1

process above genome, alter genome trans without changing DNA sequence

Question 2

enironment

Answer 2

plants and animals change gene exp response to environment

Question 3

inherited

Answer 3

eg mouse, fear conditioning, shocks to mice
advantageous to be cautious of predator

eg daphnia (water flea)
grow protective helmets in presence of predators- mother have helmets even though no predators, offspring still develop

eg if mice mothers do lick offspring, shows caring, if they do not, not caring… passed on

Question 4

agouti gene

Answer 4

mothers fur colour influences pups, grandchildren get dark fur if grandmother had it

Question 5

organisation of DNA in cell

Answer 5

1. supercoiled, compact, organise = chromatin
2. heterochromatin= dnesly packed, not as expressed
3. euchromatin= open, often expressed

Question 6

mechanisms- prevent exp of changed phenotype

Answer 6

1. histones
2. dna methylation
3. remodelling complexes
4. histone variants
5. non- coding RNA

Question 7

dna methylation

Answer 7

animals, plants, fungi
high methylation, low trans
found in promoters in vertebrates

Question 8

disease

Answer 8

cancer tissue reduced methylation, divides out of control, silencing tumour supp genes

Question 9

external stimuli

Answer 9

can alter epigenetic modification
eg heat stress