Haploid Mapping Flashcards
1
Q
Linkage Mapping in haploids
A
- no dominance/recessive relationships (genotype = phenotype)
- high numbers of progeny, very closely linked genes
- direct analysis of meiotic products, double crossovers between genes
2
Q
Allele segregation w/p cross over
A
- 4 spores with the A phenotype
- 4 spores with the a phenotype
-The A and a alleles segregate during the 1st meiotic division
3
Q
Allele segregation w/ cross over
A
-2 spores with the A phenotype
-2 spores with the a the phenotype
-2 spores with the A phenotype
2-spores with the a phenotype
-The A and a alleles did not fully segregate until the 2nd meiotic division
4
Q
FDS
A
- first division segregation
- phenotypic arrangement of spores, 4:4
- indicates no cross-over between gene and centromere
5
Q
SDS
A
- second division segregation
- -phenotypic arrangement of spores, 2:2:2:2
- indicates single cross-over between gene and centromere
6
Q
a +
a +
+ a
+ a
A
FDS
7
Q
a + a +
+ a + a
+ + a a
a a + +
A
SDS
8
Q
Calculating m.u. between locus and its centromere
A
1/2(SDS)/(total) * 100
9
Q
AB
AB
ab
ab
A
PD, parental ditype
10
Q
AB
Ab
aB
ab
A
TT, tetratype
11
Q
Ab
Ab
aB
aB
A
NPD, nonparental ditype
12
Q
Assumption:
A
- all double CO events
- are equal frequency
13
Q
m.u. between two genes formula
A
[0.5TT + 3NPD]/total asci * 100 = m.u.
14
Q
Genes are linked
A
NPD «< PD
15
Q
Genes are unlinked
A
NPD = PD
