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