lecture 30

Question 1

what is the genetic material of an organism called?

Answer 1

genome

Question 2

what is the record of the chemical changes to the DNA and histone proteins of an organism called?

Answer 2

epigenome

Question 3

at what point in development are epigenetic tags erased from parental chromsoomes?

Answer 3

the first few days after fertiliizaton

Question 4

what are the epigenetic tags that are left after most are erased called?

Answer 4

imprinted genes

Question 5

what transfers epigentic information rather than just DNA sequences to offspring?

Answer 5

imprinted genes

Question 6

what do epigenetic tags do during cell specialization in an embryo?

Answer 6

they either activate or silence gene sequences which leads to further specializaiton

Question 7

what is different at a genetic level in identical twins once they reach adulthood and why?

Answer 7

epigenome patterns because they are affected by environmental factors

Question 8

do epigenetic tags change the genetic code?

Answer 8

no

Question 9

how do epigenetic tags affect gene expression?

Answer 9

methylation and chromatin remodeling

Question 10

what does methylation do to transcription in eukaryotic genes?

Answer 10

it silences it, especiallly in promotor region

Question 11

what are CpG islands?

Answer 11

sequences of DNA(~1000-2000 nucleotides long) with a lot of CG repeats located near promotor regions

Question 12

how are housekeeping genes expressed?

Answer 12

constitutively(all the time)

Question 13

are CpG islands methylated or unmethylated in housekeeping genes?

Answer 13

unmethylated

Question 14

where is tissue specific gene expression regulated?

Answer 14

at CpG islands (by methylation)

Question 15

where does a transcriptional activator bind?

Answer 15

to the enhancer located in the CpG island located before the core promotor which is before the coding sequence (of unmethylated DNA)

Question 16

wat blocks transcriptional activator binding?

Answer 16

methyl groups on CpG island near enhance

Question 17

what does methyl-CpG do?

Answer 17

it binds to the methyl groups that have been added to the DNA, thereby coiling it, resulting in heterchromatin

Question 18

what is lyonization?

Answer 18

inactivation of one random X chromosome to not produce twice the gene product

Question 19

what is a Barr body?

Answer 19

supercoiled X chromosome

Question 20

what impacts the different color dispersions of Calico cats?

Answer 20

timing of methylation

Question 21

how does diet influence epigenetics?

Answer 21

foods with folic acid and vitamin B have methyl donating nutrients that regulate gene expression

Question 22

what is epigenetic memory?

Answer 22

the idea that epigenetic modification can be passed across generations(past F1)

Question 23

how do methylation levels of cancer cells compare to those of healthy cells?

Answer 23

they are lower, activating genes that promote cell growth