Packaging of Eukaryotic DNA

Question 1

FAIRS

Answer 1

F- Flexible/ respond to external signals
A- Altered/ generate genetic diversity
I- Information
R- Replicated and transmitted accurately
S- Stable

Question 2

Composition of chromosomes

Answer 2

DNA and chromatin

Question 3

two types of protein in chromatin

Answer 3

a. histone
b. non histone chromosomal protein

Question 4

small, well-defined, basic protein

Answer 4

histone

Question 5

include diverse structural, enzymatic, and regulatory proteins

Answer 5

non-histone chromosomal protein

Question 6

H1 histones

Answer 6

linker histone

Question 7

H2-H4

Answer 7

Core histone for protection and gene regulation

Question 8

Histone H1 runs down the center of the coil acting as ___

Answer 8

stabilizer

Question 9

Two models of chromatin fiber

Answer 9

solenoid and zig-zag model

Question 10

Application of NA extraction

Answer 10

• Restriction, Gene Cloning, Amplification, DNA sequencing
• DNA profiling
• Molecular biotechnology
• Phylogenetic studies

Question 11

General Steps in NA isolation

Answer 11

1. Tissue Homogenization and Cell lysis
2. Denaturation and separation of other biomolecules from the NA
3. Precipitation of NA from an aqueous phase
4. Washing of precipitated NA
5. Drying of pellet and dissolution of dried pellet

Question 12

Mechanical method for tissue homogenization

Answer 12

sonication and grinding

Question 13

Chemicals for extractions

Answer 13

Salt, Buffer, Surfactant Reagents, Denaturant, Enzyme treatment

Question 14

Surfactant reagent (SDS)

Answer 14

Sodium dodecyl sulfate

Question 15

• Phenol denatures
• Chloroform denatures
• Isoamyl alcohol removes

Answer 15

proteins; proteins and lipids; phenol

Question 16

CTAB removes

Answer 16

cetyltrimethylammonium bromide remove polysaccharide

Question 17

PVP removes

Answer 17

polyvinylpyrrolidone removes polyphenol

Question 18

Monovalent cations

Answer 18

sodium potassium

Question 19

Alcohol for precipitation

Answer 19

Ethanol or isopropanol

Question 20

Main methods for washing of precipitated NA

Answer 20

alcohol wash (ethanol/ isopropanol), and centrifugation

Question 21

dissolution of dried pellet in

Answer 21

sterilize molecular grade water and Tris-EDTA (Ethylenediaminetetraacetic acid)

Question 22

EDTA inactivates

Answer 22

DNAses

Question 23

___ treatment if DNA is isolated

Answer 23

RNAs

Question 24

___ treatment if RNA is isolated

Answer 24

DNAs

Question 25

Storage: - stock solution at ___ C - working solution at ___ C

Answer 25

-80C; 4C

Question 26

Determination of purity and concentration: - using ___ (different conc.) - ___

Answer 26

DNA standard; UV Spectrophotometer

Question 27

If a260/280: <1.7 (or <1.6) >2.0

Answer 27

Protein contamination Chloroform/ phenol conc.

Question 28

If A260/ 230: <2.0

Answer 28

contam'd with carbohydrate carryover, residua phenol/ guanidinium, or organic compounds, salt

Question 29

movement of electrically charged molecules in an electrical field for separation and visualization of DNA

Answer 29

Gel electrophoresis

Question 30

Allows molecular separation based on

Answer 30

size and net charge

Question 31

Gel used on GE

Answer 31

agarose or acrylamide

Question 32

DNA migrates to anode (+) at a rate inversely proportional to its ___

Answer 32

molecular weight

Question 33

Stain used in GE

Answer 33

EtBr (ethidium bromide) that emits red-orange

Question 34

Buffers for GE

Answer 34

TAE- Tris-Acetate EDTA (common) TBE- Tris-Borate EDTA (stronger)