pack 9- epigenetics

Question 1

DNA methylation

Answer 1

methyl groups attach to DNA bases
stop RNA polymerase binding to DNA
gene is switched off, transcription cant happen so no mRNA
no protein made
no gene expressed

Question 2

Histone modification

Answer 2

methyl or acetyl groups attach to histone tails
affect how tightly DNA wind s around histone
tightly = gene inaccessible, switched off cannot transcribe, no mRNA, no protein, gene not expressed
loose = gene accessible, transcribed, expressed

Question 3

effect of diet- agouti gene

Answer 3

mother with gene- fed methyl rich diet
DNA methylation of agouti gene
switch off gene
gene not expressed
offspring not have gene