Genetics

Question 1

define the concept of precision medicine

Answer 1

give people the most effective treatment based on their genes as everyone is different

Question 2

three ways DNA can be damaged?

Answer 2

1. DNA strand breaks
2. chemical crosslinking
3. mismatched bases

Question 3

which phase of the cell cycle does DNA replication happen?

Answer 3

S phase

Question 4

four things that determine the amount of protein produced?

Answer 4

1. rate of transcription
2. rate of splicing of mRNA
3. half life of mRNA
4. rate of processing polypeptide

Question 5

define polymorphism

Answer 5

variation in the human genome that has a population frequency of greater than 1% and in itself is not disease-causing.

Question 6

define mutation

Answer 6

a gene change that causes a genetic disorder

Question 7

three ways a chromosome can be recognised?

Answer 7

1. banding pattern with specific stains
2. length
3. position of centromere

Question 8

define acrocentric chromosome

Answer 8

short arm does not matter

Question 9

describe balanced chromosome arrangement

Answer 9

all chromosomal material is present

Question 10

describe unbalanced chromosome arrangement

Answer 10

extra or missing chromosome material

Question 11

four chromosomal mutations

Answer 11

1. aneuploidy- extra or missing chromosomes
2. translocation- rearrangment of chromosomes
3. insertions and deletion- missing or duplicated material
4. micro deletions

Question 12

define robertsonian translocation

Answer 12

two acrocentric chromosomes stuck end to end

Question 13

molecular cytogenetics

Answer 13

detects small changes

Question 14

array CGH

Answer 14

detects any size of imbalance but not balanced rearrangements

Question 15

define mosaicism

Answer 15

different cells have different genetic constitution

Question 16

define somatic mosaicism

Answer 16

two genetically distinct populations of cells derived from post zygotic mutations

Question 17

Her2 amplification

Answer 17

monoclonal antibody- trastuzamab

Question 18

philadelphia chromosome

Answer 18

tyrosine kinase inhibitor- imatinib

Question 19

what does aCGH analyse for

Answer 19

deletions and duplications, but does not detect balanced arrangements

Question 20

other methods that mutations can be detected?

Answer 20

PCR, next generation sequencing

Question 21

what does a promoter mutation cause

Answer 21

1. no, or reduced transcription

2. no, or reduced protein

Question 22

define a missense mutation

Answer 22

single nucleotide change that results in a different amino acid

Question 23

mutation nomenclature

Answer 23

c. is the effect on the mRNA

p. effect on peptide sequence

Question 24

three things you may see if there is a genetic change

Answer 24

1. disease-causing mutation
2. polymorphism
3. variant of unknown significance

Question 25

define penetrance

Answer 25

likelihood of having a disease if you have a gene mutation

Question 26

define 100% penetrance

Answer 26

you will get the disease if you have the mutation

Question 27

define mendelian disorders

Answer 27

disease that segregate in families-caused by a change in a single gene.

Question 28

examples of mendelian inheritance

Answer 28

1. autosomal dominant 2. autosomal recessive 3. X-linked 4. mitochondrial

Question 29

define autosomal dominance

Answer 29

only need one gene to get the disease- passed through families

Question 30

define autosomal recessive

Answer 30

two copies of the abnormal gene required- passed on through families.

Question 31

define X-linked

Answer 31

mutation on the X chromosome causes disease

Question 32

define multifactorial inheritance

Answer 32

many factors are involved in causing the condition.

Question 33

cancer is a disease of?

Answer 33

somatic mosaicism caused by post-zygotic mutations

Question 34

characteristics of a successful cancer cell

Answer 34

1. proliferation 2. evading immune response 3. acquiring a vascular supply 4. avoiding apoptosis 5. metastasis

Question 35

hall marks of cancer (6)

Answer 35

- self-sufficiency in growth signals - insensitivity to anti-growth signals - tissue invasion and metastasis - limitless replicative potential - sustained angiogenesis - evading apoptosis

Question 36

four genes involved in cancer

Answer 36

oncogenes tumour suppressors DNA repair genes drug metabolism (metabolise carcinogens)

Question 37

when cancer is sequenced there are two mutations that indicate cancer

Answer 37

1. driver mutations | 2. passenger mutations

Question 38

methylation

Answer 38

addition of a methyl group which usually occurs on cytosine bases just before guanine bases

Question 39

what does methylation cause

Answer 39

de-acetylation by modification of histones repressing transcription

Question 40

methylation causes the environment to effect our genes?

Answer 40

yes

Question 41

which mutation does methylation make more likely?

Answer 41

C to T

Question 42

why do tumours get so many mutations?

Answer 42

the cells have a high rate of mutability and there is a loss of DNA repair

Question 43

what determines the characteristics of cancer

Answer 43

driver mutations, not the tissue of origin

Question 44

explain the two hit hypothesis

Answer 44

first hit is inherited mutation | second hit is an acquired mutation. However both can be acquired mutations

Question 45

three mechanisms of gene activation

Answer 45

1. duplication of a gene 2. activation of the gene promoter 3. change in amino acid sequence

Question 46

define philadelphia chromosome

Answer 46

abnormal small chromosome

Question 47

define caveat

Answer 47

female carrier who may have some mild features of an X-linked disease

Question 48

define X-inactivation

Answer 48

females only have one active X-chromosome

Question 49

define single nucleotide polymorphism

Answer 49

alteration in DNA sequence that is not in itself disease causing

Question 50

define copy number variations

Answer 50

extra or missing stretches of DNA

Question 51

non-mendelian inheritance disease examples

Answer 51

1. methylation 2. mitochondrial inheritance 3. mosaicism

Question 52

define psychological capability

Answer 52

ability to engage in the necessary mental processes

Question 53

define physical capability

Answer 53

skill, strength or stamina

Question 54

define reflective motivation

Answer 54

planning and evaluation

Question 55

define automatic motivation

Answer 55

emotional reactions, desires, impulses, inhibitions, reflexes

Question 56

define physical opportunity

Answer 56

opportunity afforded by the environment (time, resources, physical activity)

Question 57

define social opportunity

Answer 57

opportunity afforded by social and culture norms