Test
Gene Hunting and Mapping
Preguntas del test (35)
1Linkage mapping- determining the distance between & order of genes
- AVerdadero
- BFalso
2Genetic maps are measured in bp, physical maps in cM
- AVerdadero
- BFalso
3Linkage _ reflects gene proximity
- ADirectly
- BIndirectly
- CLoosely
4Genes on different chromosomes link dependently
- AVerdadero
- BFalso
5What are the two definitions of haplotype?
- AA set of genes on the same chromosome
- BThe genes contained in two homologous chromosomes
- CA set of genetic determinants
6What does this symbolise?
- AThe recombination frequency
- BThe location of the SNP marker
- CThe first infected generation
7Name two resons why large families are required for linkage studies in humans (for an accurate result)
- AHuman families are small
- BHumans cannot be bred just to investigate phenotypes
- CHuman genes are highly conserved
- DHuman gene markers are rare
8If 15% of meioses in a study show crossover, what is the recombination frequency?
- A15%
- B30%
- C85%
9Loci with a recombination factor of 50% have the same chance of being separated as loci on different chromosomes
- AVerdadero
- BFalso
10Name the two steps required for functional mapping
- AFind what haplotype those with the mutations share
- BFind what markers those with the mutations share
- CLook for markers close to it
- DLook for genes close to it
11What is the 'Critical Region'
- AThere area containing the mutated gene
- BThe area containing the related marker
12A, 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?
- ABetween B & C
- BBetween A & D
- CBetween B & D
- DBetween A & C
13Assuming a person is heterozygous, what do we need to know once markers for the alleles have been identified?
- AWhich marker is segregated with which allele i.e A1D A2d, or A1d A2D
- BWhich allele is diseased i.e. D or d
- CWhich marker has bonded correctly
14What is the difference between phase known and phase unknown?
- AIn phase known, we know which allele contains the diease
- BIn phase known, we have the genotype of the grandparents
- CIn phase known, we don't know how many recombinants there are
15Fewer recombinants mean the hypothesis is more likely
- AVerdadero
- BFalso
16Assume 12% of people are recombinants - how many cM are the genes?
- A24cM
- B12cM
- C88cM
17Name 3 things that can affect the recombination process
- ACrossover hotspots
- BCrossovers are common near centromeres
- CCrossovers are rarer near centromeres
- DOocytes crossover more frequently than sperm
- ESperm crossover more frequently than oocytes
18LOD - Log of the Odds Ratio
- AVerdadero
- BFalso
19When using LOD, what are the two hypothesis?
- AThere is a given (previously calculated) linkage frequency
- BThere is null (50% or more) linkage frequency
20Assuming 6 recombinants out of 10 children what is the equation for the statistical likelihood of 6 recombinents?
- A[(1-θ)^6] x θ
- B[(1+θ)/6] x θ
- C[6 x θ] x θ
21The equation for NO linkage = [(1-θ)^no of children in study]
- AVerdadero
- BFalso
22A = Liklihood of linkage
B = Liklihood of no linkage
What is the LOD full equation?- ALog10 (A/B)
- BLog10 (B/A)
- CLog10 (A-B)
- DLog10 (A x B)
23-2 is considered significant, 3 is considered no linkage
- AVerdadero
- BFalso
24It is thought that 4 of 13 children are recombinants- calculate the LOD and see if this is significant
- AYes
- BNo
25LOD scores are not additive
- AVerdadero
- BFalso
26Linkage analysis in complex disorders is much more difficult
- AVerdadero
- BFalso
27The first step of mapping complex disease genes is demonstrating how important the genes are on heritability
- AVerdadero
- BFalso
28How do you gain estimates of heritability in complex disorders?
- ALook at mono/dizygotic twins
- BLook at siblings
- CLook at familial generations
29Why is linkage analysis so much more difficult with complex disorders?
- AWe don't know penetrance
- BWe don't know how many genes are involved
- CWe don't know the relative effect of each gene
30Non-parametric linkage analysis typically uses what?
- AAffected twins
- BAffected sibling pairs
- CAffected spouses
31What is true of NPL?
- ANo assumptions of no of loci/environmental role
- BNot concerned about penetrence
- CAssumed diseased individuals have alleles in common
32This image shows two siblings that are...?
- AIdentical by state
- BIdentical by descent
33The two siblings possess alleles that are...
- AIdentical by state
- BIdentical by descent
34What is used in Non-Parametric Linkage Analysis to indicate linkage?
- ADeviation from normal ratios of sibling inheritence
- BDeviation for normal ratio's of phenotype expression
- CDeviation from normal allelic ratios
35Chron's disease occurs in 1-3/10,000 people
- AVerdadero
- BFalso
Información
- Descripción
- Year 2 Test sobre Gene Hunting and Mapping, creado por gina_evans0312 el 27/12/2013.
- Autor
- gina_evans0312
- Idioma
- English
- Visitas
- 583
- Historial
- Creado el 27 dic 2013 · actualizado el 19 feb 2016
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