Wk 6 - Deck 2

Question 1

heterochromatin

Answer 1

condensed chromatin structures, little or no transcription

Question 2

transient signal

Answer 2

initiates feedback loop for specific protein that continues to create transcription factor for itself

Question 3

are histone modifications inherited?

Answer 3

yes, the daughter cells only get half of the modification, but proteins can recognize these patterns, and then re-modify

Question 4

MyoD activates_____

Answer 4

myosin, actin, Myf

Question 5

example of the “position effect”

Answer 5

white gene in fly eyes. All the cells have exactly the same DNA, but the heterochromatin expanded in some cells and not others, and that state is remembered.

Question 6

a _____ recognizes, and a _______ modifies a region of chromatin

Answer 6

reader, writer

Question 7

X chromosome inactivation

Answer 7

in females, one is shut down by heterochromatin mechasim

Question 8

what do cells do when they recognize a hemi(partially) methylated base pair?

Answer 8

they secrete methyltransferase, which methylates the non-methylated nucleotide of the pair and restores the methylated state

Question 9

what are common targets of methylation

Answer 9

CG pairs

Question 10

MyoD

Answer 10

master regulatory switch gene for Muscle (transcription factor)

Question 11

ectoderm example

Answer 11

brain

Question 12

______ __________ __________can reposition nucleosomes and control transcription

Answer 12

chromatin remodeling complexes

Question 13

mesoderm example

Answer 13

percursor of muscle

Question 14

the pattern of modification of ______ tails can regulate transcription

Answer 14

histone

Question 15

3 types of cellular memory mechanism

Answer 15

positive feedback loops
inheritance of dna methylation patterns
inheritance of chromatin states

Question 16

can methylation be reversed?

Answer 16

yes, certain enzymes can

Question 17

euchromatin

Answer 17

extended chromatin structures, more accessible to transcriptional machinery, about 90% of a typical interphase chromosome

Question 18

Methylation of _______ bases in DNA can repress transcription

Answer 18

cytosine

Question 19

what’s the cause of a tortoise shell cat?

Answer 19

heterochromatin activation, remembered by specific cells

Question 20

endoderm organ

Answer 20

pancreas, liver

Question 21

methylation typically ________ the expression of a gene

Answer 21

inhibits

Question 22

DNA packaging , small to large

Answer 22

DNA, Histone, Nucleosome, chromatin, chromosome

Question 23

the chromatin remodeling complex is ________ dependent, making it an _________

Answer 23

ATP, atpase