(M) DNA extraction, PCR, and Gel Electrophoresis

Question 1

This is the repository of genetic information

Answer 1

DNA

Question 2

What constitutes DNA

Answer 2

long chains of nucleotides

Question 3

Enumerate the three steps of DNA extraction

Answer 3

1. Lysis
2. Precipitation
3. Purification

Question 4

ln this stage, the cell’s integrity and the nucleus are disrupted to release enclosed DNA

Answer 4

lysis

Question 5

two types of lysis

Answer 5

mechanical disruption
cell / chemical lysis

Question 6

This type of lysis utilizes detergents and enzymes such as proteinase K

Answer 6

Chemical / cell lysis

Question 7

type of lysis which utilizes tissue homogenization using mortar and pestle or finely cutting tissue into small fragments

Answer 7

mechanical disruption

Question 8

mechanical disruption is important to what type of cell and why?

Answer 8

plant cells due to rigid cell walls

Question 9

What does the proteinase K dssolve to release DNA from cell compartments?

Answer 9

cellular proteins (such as histones)

Question 10

this secondary step in DNA extraction separates DNA from the debris

Answer 10

precipitation

Question 11

What is used to neutralize DNA’s negative charge, promoting stability and reduced water solubility

Answer 11

salt

Question 12

Why is alcohol used in DNA precipitation to isolate the nucleic acids

Answer 12

because DNA is insoluble in alcohol,

Question 13

In this phase, the separated DNA is cleansed from the remaining cellular residue through a rinsing
process, enhancing its purity

Answer 13

purification

Question 14

This allows an extremely large number (at least 1Billion) of
copies to be synthesized of any given DNA sequence.

Answer 14

polymerase chain reaction

Question 15

PCR requires these to proceed

Answer 15

1. target DNA
2. 2 primers
3. All 4 types of deoxyribonucleoside triphosphates
4. Thermostable DNA pol (Taq DNA)
5. thermal cycler

Question 16

Enumerate the three steps of PCR cycle

Answer 16

Denaturation
Primer Annealing
Elongation

Question 17

This step of PCR heats the reaction mixture to 95°C for a brief period

Answer 17

Denaturation

Question 18

What happens during denaturation

Answer 18

separation of DNA to single strands so that they can be used as templates for DNA synthesis

Question 19

This step of PCR rapidly cools the mixture

Answer 19

primer annealing

Question 20

To what temp should the mixture be cooled down to for primer annealing?

Answer 20

37-65°C (module)
55-60°C (vid lec)

Question 21

Where does primers attach within the DNA strands

Answer 21

each side of the target DNA sequence

Question 22

During this phase, DNA polymerase
extends the primers by copying the single-stranded templates.

Answer 22

elongation

Question 23

T or F

Primer annealing creates partially double-stranded DNA segments

Answer 23

F elongation

Question 24

T or F
Primer annealing lowers the temperature to facilitate primer attachment

Answer 24

T

Question 25

T or F
the 3 steps of PCR are repeated multiple times up to 60 cycles

Answer 25

F (40 lang)

Question 26

T or F
Shorted DNA segments require lower denaturation temperatures and shorter times

Answer 26

T

Question 27

T or F
Times and temp during each step vary based on the length of the primers and target segment

Answer 27

T

Question 28

This is based on the migration of charged particles in an electric field on the way to an electrode with opposite charge

Answer 28

electrophoresis

Question 29

The mobilities of moving particles / molecules depend on these

Answer 29

size and charge

Question 30

Pertaining to a fundamental technique with various applications in molecular biology

Answer 30

Gel electrophoresis

Question 31

application of gel electrophoresis in molecular biology which uses a fluorescent stain and radioisotopes for labelling

Answer 31

visualization and staining

Question 32

application of gel electrophoresis in molecular biology that compares the migration of DNA bands in the sample with those of a DNA size standard or ladder

Answer 32

Size estimation

Question 33

This serves as a reference for size estimation

Answer 33

DNA ladder

Question 34

What is the fluorescent stain commonly used that intercalates with DNA and emits fluorescence when exposed to UV light

Answer 34

ethidium bromide

Question 35

These are used for labeling in visualization and staining

Answer 35

radioisotopes

Question 36

application of DNA gel electrophoresis

Answer 36

DNA sequencing
Genotyping
Restriction fragment length polymorphism (RFLP) analysis