MCQ 2

Question 1

Southern blotting

Answer 1

A method to detect single stranded DNA that has been transferred to nylon paper by using a probe that binds DNA

Question 2

Northern blotting

Answer 2

Hybridisation technique where a DNA probe binds to an RNA target molecule

Question 3

Steps of Southern blotting

Answer 3

Target DNA cut with restriction enzyme
Fragments separated by gel electrophoresis
dsDNA melted by soaking gel in alkaline denaturing solution
DNA fragments transferred to nylon membrane
Membrane dipped in solution of labelled DNA probes molecules

Question 4

What’s an example of a alkaline denaturing solution?

Answer 4

Sodium hydroxide

Question 5

How do the DNA probe molecules work in Southern blotting?

Answer 5

They only bind to DNA fragments with similar sequences
Makes area radioactive
A black spot will appear where the hybrid molecule is if a piece of photographic film is placed on top

Question 6

What makes the primers needed for PCR?

Answer 6

Primase

Question 7

Why is SYBRR green a useful reagent for real time PCR?

Answer 7

It flouresces only when bound to dsDNA

Question 8

What are the mains things needed in a PCR reaction mixture?

Answer 8

DNA polymerase
Primers
Deoxyribosenucleoside triphosphates

Question 9

What type of template is needed for RT-PCR

Answer 9

RNA template

Question 10

What type of template is needed for inverse PCR?

Answer 10

A circular template

Question 11

Which variant of PCR may be used to selectively amplify mRNAs from a sample of total cellular RNA?

Answer 11

Differential display PCR

Question 12

What are the steps and temperatures of DNA in order?

Answer 12

Strands melt @ 90oC
Primers anneal @ 50-60oC
DNA synthesis @70oC

Question 13

What is responsible for DNA synthesis in PCR?

Answer 13

Taq polymerase

Question 14

Inverse PCR

Answer 14

Method for using PCR to amplify unknown sequences by circularising the template molecule

Question 15

When do you use inverse PCR?

Answer 15

When you know a bit of a DNA sequence in the middle but not the bits either side

Question 16

Degenerate primer

Answer 16

A primer with several alternative bases at certain positions

Question 17

Long PCR

Answer 17

PCR reaction used specifically to amplify longer target sequences than standard PCR

Question 18

Hot start PCR

Answer 18

Taq polymerase is kept inactive at low temperatures by antibodies or blocking proteins to make sure template DNA is fully denatured

Question 19

Unique steps of inverse PCR

Answer 19

Restriction enzymes cut DNA sequence, but not known area
Fragment ligated so it circularises
Primers used that face outwards from known sequence
PCR run on circular DNA

Question 20

What does inverse PCR result in?

Answer 20

Strands of DNA with known sequence at the ends

Question 21

Randomly amplified polymorphic DNA (RAPD)

Answer 21

Method for testing genetic relatedness using PCR to amplify arbitrarily chosen sequences

Question 22

Reverse transcriptase PCR

Answer 22

Allows genes to be amplified and cloned intron free

Uses mRNA and reverse transcriptase to make copies (cDNA)

Question 23

Differential display PCR

Answer 23

Variant of RT-PCR that specifically amplifies mRNA from eukaryotic cells using oligo(dT) primers

Question 24

Oligo(dT) primer

Answer 24

Primer used on 3’ end of cDNA in differential display PCR

Question 25

Rapid amplification of cDNA ends (RACE)

Answer 25

RT-PCR based technique
Uses internal primers to speed to up copying
Can work 3’ to 5’

Question 26

Real time fluorescent PCR

Answer 26

Uses DNA binding probes that fluoresce more or only when bound to dsDNA
As more dsDNA is produced, fluorescence increases as more probe binds

Question 27

Multiplex PCR

Answer 27

Real time PCR reaction
Uses multiple fluorescent dyes on different probes
Assesses amplification of more than one target sequences

Question 28

Long interspersed element

Answer 28

Makes up majority of moderately repetitive DNA
Long sequences of DNA
Found in multiple copies

Question 29

Short interspersed element

Answer 29

Short repetitive sequences of DNA that are highly repetitive

Question 30

Satellite DNA

Answer 30

Highly repetitive DNA of eukaryotic cells
Found as long clusters of tandem repeats
Permanently coiled tightly into heterochromatin

Question 31

Tandem repeats

Answer 31

Repeated sequences of DNA/RNA that lie next to each other

Question 32

How many base pairs in a microsatellite?

Answer 32

~13

Question 33

How mant base pairs in a minsatellite?

Answer 33

~25

Question 34

Variable number tandem repeats (VNTR)

Answer 34

Cluster of tandemly-repeated sequences in DNA

Numbers of repeats differs from one individual to another

Question 35

What is used in DNA fingerprinting?

Answer 35

Variable number tandem repeats (VNTR)