Mutations and genetic analysis

Question 1

3 types of chromosomal abnormalities

Answer 1

Numerical
Structural
Mutational

Question 2

When is there a high incidence of mutation in pregnancy

Answer 2

First trimester with trisomy

Question 3

Mostly maternal non disjunction syndromes - trisomy

Answer 3

Patau - extra 13
Edwards - extra 18
Down - extra 21
Klinefeller - XXY

Question 4

Monosomy

Answer 4

Turners have one X

Question 5

Downs syndrome

Answer 5

Advancing maternal age and problem with non disjunction

Facial dysmorphologies, 50-60 years and alzheimers

Question 6

Patau syndrome

Answer 6

5% die in first month and due to non disjunction

Question 7

Edwards syndrome

Answer 7

Developmental problems

Question 8

Turners syndrome

Answer 8

Short females with neck webbing and wide spaced nipples who are infertile
Normal intelligence and lifespan

Question 9

Klinefeler Syndrom

Answer 9

Gynaecomastia and are tall with long limbs and small testes with mild learning difficulties

Question 10

Balanced

Answer 10

All genetic information still present but just in the wrong place

Question 11

Robertsonian translocation

Answer 11

fuse 2 acrocentric chromosomes can lead to downs syndrome

Question 12

Reciprocal translocation

Answer 12

Partial monosomy or trisomy

Question 13

Paracentric inversion

Answer 13

Not too harmful

Question 14

Pericentric inversion

Answer 14

Include centromere

Question 15

Transition point mutation

Answer 15

Purine=> purine

Pyrimidine => pyrimidine

Question 16

Transversion point mutation

Answer 16

purine<=> pyrimidine

Question 17

PCR requirements

Answer 17

Heat tolerant Tac polymerase and polymerase
Sequence information and DNA
Oligonucleotide primers
Nucleotide

Question 18

Name some uses of PCR

Answer 18

DNA cloning
In vitro mutagenesis
Forensic medicine
Gene identification for mutations

Question 19

Name the 3 consecutive temperatures for denaturing, annealing and extending the DNA

Answer 19

93-95
50-70
70-75

Question 20

Gel electrophoresis

Answer 20

Separate compounds on size and density

Apply electric field over agarose gel and negative DNA ==> positive electrode

Question 21

What are some advantages of PCR

Answer 21

Fast, easy to use, sensitive and robust

Question 22

ARMS

Answer 22

Like PCR but a different primer used to detect single base mutations and deletions

Question 23

In ARMS explain the link between wild type allele and primer

Answer 23

Normal = Amplified
Mutant = not amplified

Question 24

In ARMS explain the link between mutant allele and primer

Answer 24

Normal primer = no amplification

Mutant primer = amplification

Question 25

Advantages of ARMS

Answer 25

Cheap and no label needed

Question 26

State some slight drawbacks of ARMS

Answer 26

Electrophoresis also needed and the primer design is critical

Question 27

State the disadvantages of ARMS

Answer 27

Need sequence information
Limited amplification size
Limited amounts of product
Infidelity of DNA replication

Question 28

Restriction endonuclease

Answer 28

Enzyme used in RFLP from bacterial cell that always cuts DNA at the same sight by recognising specific parts of DNA and degrades DNA of incoming virus
Protective mechanism

Question 29

Explain some positives/negatives of RFLP

Answer 29

Simple cheap and non radioactive

When electrophoresis is not always feasible

Question 30

DNA sequencing

Answer 30

Precise order of nucleotide

Question 31

ddNTP’s

Answer 31

Chain elongating inhibitors of DNA polymerase

Question 32

Some negatives/positives of DNA sequencing

Answer 32

Gold standard

Extensive equipment required and has poor quality read ( 70-900) bases

Question 33

What do you base the decision on which mutation detecting method is used?

Answer 33

Sensitivity and specifity