lecture 8

Question 1

chromosome

Answer 1

structure of organized DNA in eukaryotic cell

Question 2

in eukaryotes DNA combine with what to produce what?

Answer 2

histones, nucleosomes

Question 3

nucleosomes fold up and compress to produce what?

Answer 3

chromatin

Question 4

chromatin fiber coiled into what

Answer 4

chromatid

Question 5

what constitutes a chromosome

Answer 5

chromatid

Question 6

how many histones in protein core?

Answer 6

8; 2 each of H2A,H2B,H3,H4

Question 7

which histone is between nucleosomes?

Answer 7

H1

Question 8

chromatosome consists of what

Answer 8

the nucleosome plus the H1 histone

Question 9

nucleosome fold up to produce what

Answer 9

30nm fiber

Question 10

30nm fiber forms what

Answer 10

loops and 300 nm

Question 11

300nm fiber are

Answer 11

compressed to produce 250nm wide

Question 12

tight coiling of the 250nm produces what

Answer 12

chromatid of a structure

Question 13

two types of chromatin

Answer 13

euchromatin and heterochromatin

Question 14

euchromatin

Answer 14

decondensed chromosome

Question 15

what constitutes the majority of chromosome material?

Answer 15

euchromatin

Question 16

heterochromatin.

Answer 16

condensed, contains non coding DNA, centromere and telomere

Question 17

what includes most of the genes?

Answer 17

euchromatin

Question 18

what has long sequences of tandem repeats?

Answer 18

heterochromatin

Question 19

half life in prokaryotes and eukaryotes

Answer 19

prokaryotes are short, eukaryotic is longer

Question 20

histone acetylation does what?

Answer 20

weakens interaction between DNA and histone permits transcription factors to bind

Question 21

FLC encodes what

Answer 21

regulator protein that represses flowering

Question 22

FLD encodes what?

Answer 22

deacetylation

Question 23

what does the FLD ?

Answer 23

it removes the acteyl group from the FLC group allowing it to become condensed and therefor not expressed.

Question 24

DNA is most common on what?

Answer 24

cytosine adjacent to guanine (CpG)

Question 25

DNA methylation does what to transcription?

Answer 25

represses it

Question 26

histone methylation and acetylation do what?

Answer 26

activates gene expression

Question 27

GAL4 is what?

Answer 27

transcriptional activator protein. regulates transcription of genes whose products metabolize galactose

Question 28

GAL4 binds to what

Answer 28

UASg enhancer

Question 29

what happens when there is no galactose?

Answer 29

GAL80 binds to GAL4 and there is no transcription

Question 30

what happens when galactose is present?

Answer 30

GAL80 doesnt bind and transcription takes place

Question 31

when galactose is present it binds to what?

Answer 31

GAL3 which brings about a change in the conformation of GAL80

Question 32

example of mRNA alternative splicing

Answer 32

one gene encodes two different proteins; large T and small T

Question 33

with respect to large and small T. SF2 does what?

Answer 33

enhances the mRNA splicing encoding for small T antigen

Question 34

use of the first 5' splice site produces mRNA that encodes for what?

Answer 34

large T antigen

Question 35

use of second 5' splice site produces mRNA that encodes what?

Answer 35

small T antigen

Question 36

SF2 enhances the use of which splice site?

Answer 36

second

Question 37

how many human genes are regulated by RNAi

Answer 37

30%

Question 38

RNAi is triggered by what? which are generated from what

Answer 38

miRNA and siRNA, double stranded RNA

Question 39

miRNA transcription through what

Answer 39

inverted repeat in the DNA

Question 40

what produces an RNA molecule that folds to produce double stranded RNA

Answer 40

miRNA

Question 41

double stranded RNA in miRNA is cleaved by what

Answer 41

enzyme dicer

Question 42

enzyme dicer produces what

Answer 42

mirna and sirna

Question 43

siRNA is what

Answer 43

double stranded RNA

Question 44

double stranded RNA in siRNA arises from what?

Answer 44

viruses or hairpins

Question 45

inhibition of transcription?

Answer 45

siRNA

Question 46

inhibition of translation?

Answer 46

miRNA

Question 47

how is RISC formed?

Answer 47

miRNA or siRNA pair with protein

Question 48

siRNA in RISc does what

Answer 48

pairs with miRNA and RISC cleave it

Question 49

after cleave with siRNA what happens?

Answer 49

it is degraded

Question 50

miRNA in RISc does what?

Answer 50

pairs imperfectly which inhibits translation

Question 51

siRNA in RITS causes what

Answer 51

methylation which restricts transcription