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Flashcards in Genetics Deck (38)
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1

What happens in mitosis?

1 diploid parent cell --> 2 identical diploid daughter cells

2

What happen in meiosis?

1 diploid parent cell --> 4 haploid daughter cells

3

What is a polymorphism?

Any variation in the human genome that has a population frequency of greater than 1% (does not cause disease in its own right)

4

What does aneuploidy mean?

Whole extra or missing chromosome

5

What is translocation?

Rearrangement of chromosomes

6

What is Down's syndrome?

Extra chromosome 21

7

What are the chances of a woman who already has a child with Down's syndrome having another?

1%

8

What are the stages of the cell cycle?

G1 - cell grows in prep for DNA replication
S - DNA replication
G2 - make sure DNA replication occurred properly
M - mitosis - cell division

9

What is trisomy 18 called?

Edwards syndrome

10

What is trisomy 13 called?

Patau syndrome

11

What is 47XXY called?

Klinefelter syndrome

12

2 main types of translocation

Balanced
Unbalanced

13

What is robertsonian translocation?

An entire chromosome has attached to another at the centromere

14

What is a reciprocal translocation?

Where segments from 2 different chromosomes have been exchanged

15

Syndromes caused by deletion

DiGeorge's syndrome
William's syndrome
Cri du chat syndrome

16

What is amniocentesis?

Needle used to obtain sample from unborn child in utero

17

Treatment for Philadelphia chromosome?

Tyrosine kinase inhibitor: imatinib

18

What does autosomal dominant mean?

1 faulty copy of gene causes disease
50% risk

19

What does autosomal recessive mean?

2 faulty copies of the gene are needed to cause disease
25% risk if parents are carriers

20

What does x linked mean?

Disease carried on X chromosome
Female carrier - 1/2 male kids affected, 1/2 female kids carriers
Make affected - male kids normal, female kids carriers

21

What does mitochondrial inheritance mean?

Mitochondria always come from mother

22

What are single nucleotide polymorphisms?

Any variation in the human genome that does not cause a disease in its own right but may predispose to a common disease

23

What are copy number variations?

Extra or missing stretches of DJA

24

What is penetrance?

The likelihood of having the disease if you have the mutation

25

What is expression?

The variation in disease severity if you have the mutation

26

What is mosaicism?

When different cells have a different genetic constitution within one individual

27

When does somatic mosaicism occur?

When the somatic cells of the badly are of more than one genotype

28

What is gonadal mosaicism?

A special form of mosaicism where some gametes (i.e. Either sperm or oocytes) carry a mutation but the rest are normal

29

3 outcomes if the cell cycle is arrested

DNA repair
Apoptosis
Cancer

30

What is DNA methylation?

Epicene tic mechanism that cells use to control gene expression

31

What is Angelman's syndrome?

Neuro genetic disorder

32

What is myotonic dystrophy?,

I a chronic, slow progressing, inherited multi systemic disease

33

Clinical features of myotonic dystrophy

Muscular dystrophy
Cataracts
Heart conduction defects
Endocrine changes
Myotonia (slow relaxation of muscles after contraction)

34

What is huntingtons disease?

Neurodegenerative genetic disorder that afters muscle coordination and leads to cognitive decline and psychiatric problems

35

What is anticipation?

Where disease symptoms become more severe from generation to generation and may become onset at a much earlier age

36

What is heteroplasmy?

Different daughter cells contain different proportions of mutant mitochondria (similar to mosaicism)

37

What are the symptoms of mitochondrial disease?

Myopathy
Diabetes
Deafness
Optic atrophy
Stroke-like episodes
Encephalitis (inflammation of the brain)

38

4 methods by which oncogenes are activated?

Duplication of the gene
Activation of the gene promoter
Change in amino acid sequence
Phosphorylation of the gene