Case 2

Question 1

Exact multiples of n refers to…

Answer 1

Euploidy

Question 2

Chromosomes in multiples of n…

Answer 2

Polyploidy

Question 3

Aneuploidy is…

Answer 3

Variation of the chromosomal number not in multiples of n

Question 4

What is monosomy and what is the only monosomic disease that is compatible with life?

Answer 4

The loss of one chromosome

Turners syndrome 45X

Question 5

What is trisomy and what are the names of some trisomic diseases?

Answer 5

An extra chromosome
Downs (21)
Klinefelters (47XXY)

Question 6

The failure of homologous chromosome seperation during meiosis is called what?

Answer 6

Non-disjunction

Question 7

What are the gamete karyotypes following non-disjunction at meiosis I?

Answer 7

2 x trisomy

2 x monosomy

Question 8

What are the gamete karyotypes following non-disjunction at meiosis II?

Answer 8

trisomy
monosomy
2 x genotype normal

Question 9

What occurs if non disjunction occurs early in mitosis?

Answer 9

mosaicism- severity of trisomy depends on how soon after conception the disjunction occurred

Question 10

Name 2 causes of non-disjunction…

Answer 10

advancing maternal age

absence of chiasmata (holding the homologous pairs together)

Question 11

What is the number of chromosomes following reciprocal translocation?

Answer 11

46

Question 12

What is the number of chromosomes following Robertsonian translocation?

Answer 12

45

Question 13

Define ‘acrocentric’ in relation to chromosomes. What are the acrocentric chromosomes?

Answer 13

Those with a centromere near the end of the chromosome

Question 14

What are the outcomes of Robertsion translocations?

Answer 14

Trisomy
Monosomy
Genotypically normal
Balanced translocation (carrier)

Question 15

What are the outcomes of reciprocal translocations?

Answer 15

Partial trisomy
Partial monosomy
Balanced translocation (carrier)
Genotypically normal

Question 16

Name the 3 causes of Downs syndrome…

Answer 16

Mitotic dis-junction (mosaicism)
Robertsonian translocation
Numerical disjunction at meiosis I and II

Question 17

What are twin studies?

Answer 17

Studies based on the incidence of disease between monozygotic and dizygotic twins

Question 18

What is familial clustering?

Answer 18

Studies designed to show the correlation between the closeness of genetic relation and the incidence of a particular disease

Question 19

What are adoption studies?

Answer 19

Studies designed to test the incidence of disease in different environments

Question 20

What does combined screening test for? When can it be used?

Answer 20

Nuchal translucency
Pregnancy associated plasma protein
hCG

10-14 weeks

Question 21

What are the results of a combined screening test deemed ‘high risk’?

Answer 21

NT greater than 3.7mm
PAPPA low
hCG high

Question 22

What does the quadruple screening test investigate? When can it be used?

Answer 22

Alpha foetal protein
hCG
Estradiol
Inhibin A

14-20 weeks

Question 23

What are the results of a quadruple screening test deemed ‘high risk’?

Answer 23

AFP low
hCG high
Estradiol low
Inhibin A high

Question 24

What is absolute risk?

Answer 24

The risk of developing a disease over a given time period

Question 25

What is relative risk?

Answer 25

The risk of developing a disease compared with another population

Question 26

What is the difference between quantitive and qualitative risk?

Answer 26

Quantitive- numbers, facts, figures

Qualitative- impact on patient

Question 27

What is the easiest way to understand risk?

Answer 27

Presented as a rate

Same common denominator

Question 28

Heuristics are…

Answer 28

Mental shortcuts to ease the decision making load. They can influence perceptions of risk

Question 29

What are the factors that effect risk perception?

Answer 29

Deliberate- logical
Experimental/affective- impact based
Intuitive- a gut feeling

Question 30

How should you communicate risk properly?

Answer 30

Use numbers
Standardised language
Common denominator
Use of absolute risk
Visual aids
Time to process

Question 31

Examples of tools for effective risk presentation include….

Answer 31

Paling perspective- chart that puts risk into everyday perspective
One thousand people tool

Question 32

What is mifepristone indicated for?

Answer 32

progesterone receptor antagonist that stimulates uterus shredding. One half of chemical abortion treatment

Question 33

What is misopristol indicated for?

Answer 33

Induces labour and foetus shredding. Second half of chemical abortion treatment

Question 34

What is risk framing?

Answer 34

Risk can be framed either positively (ie. survival rate) or negatively (ie. mortality rate). This impacts on patients decisions

Question 35

Outline criteria for abortion before the 24th week…

Answer 35

Agreed by 2 medical practitioners

Pregnancy continuation would involve risk to mothers physical/mental health greater than if pregnancy were terminated

Question 36

Outline criteria for abortion after 24th week…

Answer 36

Prevent grave/permenant injury to physical and or mental health of Mother
Risk of life to pregnant Mother
Substantial risk of severe mental or physical handicap of the baby

Question 37

What occurs during prophase?

Answer 37

Crossing over

Pair chromosomes condense

Question 38

What occurs during metaphase?

Answer 38

Homologous chromosomes line up double file along the metaphase plate
Nuclear envelope disappears

Question 39

What occurs during anaphase?

Answer 39

Spindle contracts causing chromosomes to separate to opposite poles

Question 40

What occurs during telophase?

Answer 40

Cleaves the cell into two new daughter gametes?

Question 41

What is a centromere?

Answer 41

Specialised sequence of DNA that links two sister chromatids

Question 42

What is a kinetochore?

Answer 42

A complex of proteins associated with the centromere to which the microtubule of the spindle attaches