Tetrad Analysis

Question 1

Order and unordered tetrad example

Answer 1

Ordered- neurospora crassa (8 ascospored)
Unordered- S cerevisiae

Question 2

Tetrad analysis os used for

Answer 2

Map distance between gene and centromere i.e determine recombination frequency

Question 3

Map distance in ordered tetrad

Answer 3

1/2× no of Second div segregation (crossover)×100/total no of asci

Question 4

Types of tetrad in unordered tetrad analysis

Answer 4

Parental ditype- no cross over
Non parental ditype- all recombinant no parental
Tetratype- both parental and recombinant 50%-50%)

Question 5

Recombination frequency of non ordered tetrad

Answer 5

Recombination frequency= Non parental ditype×1/2×tetratype×100/total no of tetrads