MCBG 16

Question 1

If you preform a haemoglobin electrophoresis, two bands appear. Why are 2 bands seen after performing
haemoglobin electrophoresis?

Answer 1

In a normal person there are two types of Haemoglobin in blood. HbA2 and HbA1

Question 2

Why has thalassemia not be naturally selected (died out) ?

Answer 2

Being Heterzygous gives protection against malaria

Question 3

What are reticulocytes?

Answer 3

immature RBCs - released in early response to anaemia

Question 4

What is Lassitude??

Answer 4

lack of energy due to anoxia

Question 5

What is anoxia??

Answer 5

The absense of oxygen

Question 6

osteopenia?

Answer 6

Loss in bone mass

Question 7

What is the major protein found in bone?

Answer 7

Collagen

Question 8

Why is glycine present at every 3rd position
in the polypeptide chain?
1. Needed to make Hbonds
2. Small amino acid that fits
inside the helix
3. Hydrophilic side chain to
make interactions with
other chains
4. All of the above

Answer 8

2. Small amino acid that fits

inside the helix

Question 9

What is the structure of Type I collagen? (chain type)

Answer 9

Two a1(I) and one a2(I)
chains

Question 10

In gel electrophoresis, if one band twice as intense as

the other. What does that ?mean

Answer 10

Twice as much protein

Question 11

What does the blue tinge in the sclera signify?

Answer 11

Osteogenesis imperfecta. A condition which is caused by a lack of type I collagen

Question 12

What is cytogenetics?

Answer 12

Study of inheritance in relation to the structure and function of chromosomes.

Question 13

What are the two Prenatal Diagnosis methods?

Answer 13

Chorionic Villus Sampling

Amniocentesis

Question 14

What is Aneuploidy?

Answer 14

Loss or gain of a whole chromosome.

Question 15

What is down syndrome characterised as?

Answer 15

An extra chromosome 21

Question 16

What is Edwards characterised as (chromosome wise)?

Answer 16

Edwards +18

Question 17

What is Polyploidy?

Answer 17

Gain of a whole haploid SET of chromosomes

Question 18

Whats the difference between polyploidy and anuerploidy?

Answer 18

Polyploidy - Gain of a whole haploid SET of chromosomes (+23 haploid chromosomes)

Loss or gain of a (single) whole chromosome.

Question 19

Types of polyploidy?

Answer 19

Diploid (normal number)
Triploid/triploidy (three lots of 23)
Tetraploid

Question 20

What causes Aneuploidy?

Answer 20

1. Non-disjunction

Question 21

What type of division causes mosacism?

Answer 21

Mitotic
Chromosomes can be “left-behind” at cell division because of defects in spindle
function or attachment to chromosomes

The lagging chromosome may be lost
entirely in mitosis or meiosis

Question 22

.Whats Patau Syndrome?
Chromosome effect?
Effects (2)

Answer 22

Trisomy 13

Multiple congenital abnormalities
Polydactyly

Question 23

Whats Turner syndrome?

Effects

Answer 23

45,X (female is missing an X)

Puffy feet,
redundant skin at back of neck

Question 24

Whats the difference between mosaicism and chimerism?

Answer 24

Both are two different geneotypes within the same person. Mosaicism results from one person whereas Chimerism originates from different zygotes

Question 25

Define chromosome translocation ?

Answer 25

Movement of Genetic Info from one chromosome to another

Question 26

Define a balanced chromosome translocation ?

Answer 26

An even exchange of material with no genetic information extra or missing, and ideally full functionality

Question 27

Define a unbalanced chromosome translocation ?

Answer 27

Unequal exchange of info

Get extra or missing genes

Question 28

Why is it important to understand why translocation errors occurred in meiosis or mitosis?

Answer 28

MEIOSIS - problem with all of the mothers cells

MITOSIS - problem with just that cell line

Question 29

Robertsonian Translocations

Answer 29

To acrocentric chromosomes fused together producing one big chromosome and one tiny tiny one. = 45 chromosomes

Question 30

What does Acrocentric mean?

Answer 30

The p are is so small you cannot see it

Question 31

Explain the steps in fish?

Answer 31

1) Get DNA probe (specific nucleotide sequence with labels or label attachments) and PCR it
2) De-nature DNA and add probe
3) MAGIC (aka hybridisation)
4) Wash unbound probe off
5) Visualise it using fluorescence microscopy

Question 32

V.Important. Explain what tests FISH can be used for?

4

Answer 32

MORT

1. Mircodeletion syndromes
2. Identify chromosome of origin
   3) Chromosome rearrangement/Translocation
   4) Investigate telomeres

Question 33

Name 4 different types of probes? (Think anatomy)

Answer 33

1. Locus/gene specific probes
2. Telomere probes
3. Centromere probes
4. Whole chromosome PAINTS

Question 34

Whats the issue with using Locus specific probes on Microdeletion/duplication syndromes

Answer 34

Too small to see on G-banded chromosomes. (21,22, y)

Question 35

Would you use a microarray for mutation detection

Answer 35

No

Question 36

What are the two negatives of Microarrays? (hint in terms of chromosomes)

Answer 36

1) Can’t detect balanced rearrangements

2) Not used for mutation detection

Question 37

Whats 45,X

effects?

Answer 37

Turners syndrome
Excess skin on back neck
swollen feet/hands at birth
Short statue

Question 38

Whats XXX

effects?

Answer 38

Tiple X syndrome
Low IQ
Can have normal offspring

Question 39

Whats XXY

effects?

Answer 39

Klinefelter Syndrome
More than one X for a male
Sterile
Weak muscle
Greater height
Small genitals
Breasts
Symptoms increase with more Xs

Question 40

Whats XX Male

effects?

Answer 40

XX Male syndrome

Sry gene translocated on X chromosome