Questão 1
Questão
Linkage mapping- determining the distance between & order of genes
Questão 2
Questão
Genetic maps are measured in bp, physical maps in cM
Questão 3
Questão
Linkage _ reflects gene proximity
Responda
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Directly
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Indirectly
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Loosely
Questão 4
Questão
Genes on different chromosomes link dependently
Questão 5
Questão
What are the two definitions of haplotype?
Responda
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A set of genes on the same chromosome
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The genes contained in two homologous chromosomes
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A set of genetic determinants
Questão 6
Questão
What does this symbolise?
Responda
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The recombination frequency
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The location of the SNP marker
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The first infected generation
Questão 7
Questão
Name two resons why large families are required for linkage studies in humans (for an accurate result)
Responda
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Human families are small
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Humans cannot be bred just to investigate phenotypes
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Human genes are highly conserved
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Human gene markers are rare
Questão 8
Questão
If 15% of meioses in a study show crossover, what is the recombination frequency?
Questão 9
Questão
Loci with a recombination factor of 50% have the same chance of being separated as loci on different chromosomes
Questão 10
Questão
Name the two steps required for functional mapping
Responda
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Find what haplotype those with the mutations share
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Find what markers those with the mutations share
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Look for markers close to it
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Look for genes close to it
Questão 11
Questão
What is the 'Critical Region'
Questão 12
Questão
A, B, C & D are all markers. B and C are found in homozygous form in people with autosomal recessive deafness. Where is the critical regions for genes causing this deafness?
Responda
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Between B & C
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Between A & D
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Between B & D
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Between A & C
Questão 13
Questão
Assuming a person is heterozygous, what do we need to know once markers for the alleles have been identified?
Responda
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Which marker is segregated with which allele i.e A1D A2d, or A1d A2D
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Which allele is diseased i.e. D or d
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Which marker has bonded correctly
Questão 14
Questão
What is the difference between phase known and phase unknown?
Responda
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In phase known, we know which allele contains the diease
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In phase known, we have the genotype of the grandparents
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In phase known, we don't know how many recombinants there are
Questão 15
Questão
Fewer recombinants mean the hypothesis is more likely
Questão 16
Questão
Assume 12% of people are recombinants - how many cM are the genes?
Questão 17
Questão
Name 3 things that can affect the recombination process
Responda
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Crossover hotspots
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Crossovers are common near centromeres
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Crossovers are rarer near centromeres
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Oocytes crossover more frequently than sperm
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Sperm crossover more frequently than oocytes
Questão 18
Questão
LOD - Log of the Odds Ratio
Questão 19
Questão
When using LOD, what are the two hypothesis?
Questão 20
Questão
Assuming 6 recombinants out of 10 children what is the equation for the statistical likelihood of 6 recombinents?
Responda
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[(1-θ)^6] x θ
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[(1+θ)/6] x θ
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[6 x θ] x θ
Questão 21
Questão
The equation for NO linkage = [(1-θ)^no of children in study]
Questão 22
Questão
A = Liklihood of linkage
B = Liklihood of no linkage
What is the LOD full equation?
Responda
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Log10 (A/B)
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Log10 (B/A)
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Log10 (A-B)
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Log10 (A x B)
Questão 23
Questão
-2 is considered significant, 3 is considered no linkage
Questão 24
Questão
It is thought that 4 of 13 children are recombinants- calculate the LOD and see if this is significant
Questão 25
Questão
LOD scores are not additive
Questão 26
Questão
Linkage analysis in complex disorders is much more difficult
Questão 27
Questão
The first step of mapping complex disease genes is demonstrating how important the genes are on heritability
Questão 28
Questão
How do you gain estimates of heritability in complex disorders?
Questão 29
Questão
Why is linkage analysis so much more difficult with complex disorders?
Questão 30
Questão
Non-parametric linkage analysis typically uses what?
Responda
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Affected twins
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Affected sibling pairs
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Affected spouses
Questão 31
Questão
What is true of NPL?
Responda
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No assumptions of no of loci/environmental role
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Not concerned about penetrence
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Assumed diseased individuals have alleles in common
Questão 32
Questão
This image shows two siblings that are...?
Responda
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Identical by state
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Identical by descent
Questão 33
Questão
The two siblings possess alleles that are...
Responda
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Identical by state
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Identical by descent
Questão 34
Questão
What is used in Non-Parametric Linkage Analysis to indicate linkage?
Responda
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Deviation from normal ratios of sibling inheritence
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Deviation for normal ratio's of phenotype expression
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Deviation from normal allelic ratios
Questão 35
Questão
Chron's disease occurs in 1-3/10,000 people