DNA organization

Question 1

These sequences are repeated many times within eukaryotic chromosomes

Answer 1

Repetitive DNA sequences

Question 2

which type of DNA consists of short repeated sequences, rarely transcribed into RNA and highly repetitive

Answer 2

Satellite DNA

Question 3

which type of DNA appears one after the other in clusters at particular regions on the chromosome

Answer 3

Tandem repeats

Question 4

this repeating DNA sequences 15 to 100 bp long and are found within and between genes

Answer 4

Variable number tandem repeats (VNTRS)

Question 5

these sequences are dispersed throughout genome consistsing of di,tri, tetra nucleotides

Answer 5

Short tandem repeats (STRs)

Question 6

what type of repeats are dispersed throughout genome and constitute 1/3 of human genome

Answer 6

Interspersed repeats

Question 7

what type of interspersed element has 300bp sequence present more than a million times

Answer 7

Alu, SINES (short interspersed elements)

Question 8

what repeats has several thousand base pairs with remnant of transposable elements

Answer 8

Line 1 Long interspersed elements (LINES)

Question 9

if DNA is over or under twisted, what happens

Answer 9

it will supercoil if the ends can’t rotate

Question 10

when DNA helix is underwound by 2 turns or some coils were removed

Answer 10

it is underwound circular DNA

Question 11

when ends 1 seal to end 20, this is called

Answer 11

relaxed circular DNA

Question 12

when DNA helix has a conformational change and 2 supercoils form

Answer 12

this is supercoiled DNA

Question 13

what enzyme can sever DNA and rotate ends before rejoining

Answer 13

Topoisomerase

Question 14

Agarose gel electrophoresis seperate DNA based on

Answer 14

size, charge and shape

Question 15

which fragment move faster on gel smaller /larger

Answer 15

smaller

Question 16

DNA fragment move towards with pole

Answer 16

positive electrode

Question 17

whcih runs faster on a gel supercoiled DNA/ linear DNA/ circular DNA

Answer 17

supercoiled DNA

Question 18

which chromosomes has circular, double stranded DNA compacted into nucleoid

Answer 18

Bacterial chromosomes

Question 19

Is nucleoid nuclei based or not

Answer 19

it is not

Question 20

BACTERIAL chromosomes DNA are associated with what protein

Answer 20

HU nad H-NS (histone like-nucleoid structuring protein)

Question 21

At interphase, eukaryotic chromosomes uncoil and decodnense into a form ccalled

Answer 21

Chromatin dispersed throughout the nucleus

Question 22

Chromatin appears as

Answer 22

beads on a string (nucleosomes)

Question 23

which chromatin is transcriptionally active and uncoiled

Answer 23

Euchromatin

Question 24

How do chromatin become visisble chromosomes

Answer 24

during cell division, chromatin coils and condenses back into visible chromosomes

Question 25

what are the core histones

Answer 25

H2A,H2B,H3,H4

Question 26

Which basic protein binds very well to negatively charged DNA

Answer 26

Arginine Lysine (positiveky charged)

Question 27

what digests of chromatin releases and further digest yielding fragment

Answer 27

micrococcal nuclease

Question 28

what protects DNA from nuclease enzyme

Answer 28

DNA wrapped in histones

Question 29

describe process of how nuclease attacks DNA

Answer 29

1. A small amount of nuclease cleave the "strings fo the bead" 2. release individual beads attached to about 200 bp of DNA 3. more nuclease destroys all of the unprotected DNA between beads 4. leaving a core of protein attached to 145-147 bp of DNA

Question 30

Nucleosomes organize into

Answer 30

filament

Question 31

which chromatin is mostly inactive and appears stained during interphase

Answer 31

Heterochromatin

Question 32

which chromatin appears unstained in interphase

Answer 32

Euchromatin

Question 33

which is less condensed between euchromatin/ herterochroimatin

Answer 33

euchromatin

Question 34

To allow replication and gene expression, chromatin must do what

Answer 34

1. relax compact structure 2. expose regions of DNA to regulatory protein 3. have a reversal mechanism for inactivity

Question 35

what chromosomes is created by repeated round of DNA replication with no cell division

Answer 35

Polytene chromosome

Question 36

this region is where chromosome is made less compact

Answer 36

chromosomal puff

Question 37

chromosomal puff region is more sensitive to DNase I cleavege true/false

Answer 37

true

Question 38

characteristics of expanded regions

Answer 38

active transcirption

Question 39

sensitivity of DNA to digestion by DNase I is correlated with

Answer 39

gene expression

Question 40

what enzyme is involved in histone acetylation

Answer 40

histone acetyltransferase

Question 41

addition of what group to the positively charged amino group on side chain (lysine) changes net charge of protein

Answer 41

acetyl group

Question 42

histone acetylation promotes

Answer 42

gene activity

Question 43

what enzyme is involved in methylation

Answer 43

methyltransferase

Question 44

adding of methyl group to arginine and lysine leads to

Answer 44

repression or activation

Question 45

What enzyme is involved in phosphorylation

Answer 45

kinase

Question 46

phosphate group adds to hydorxyl group of which amino acids

Answer 46

serine and histidine

Question 47

what is the DNA sequence 5'-CG-3'

Answer 47

CpG

Question 48

methylation of which group by DNA methyltransferase repress gene activity

Answer 48

cytosine

Question 49

epigenetics changes are heritable true/false

Answer 49

true