1 you mate two haploid strains of the following genotypes St

1. you mate two haploid strains of the following genotypes

Strain 1: ADE2 HIS4                 Strain 2: ade2 his4

The resulting diploid is sporulated and equal numbers of spores are plated onto different media. You collect the following data:

150 colonies on YPD

75 colonies on SC -adenine

63 colonies on SC -adenine -histidine

Based on this data, what is the genetic distance between ADE2 and HIS4?

If you are having trouble with this question, try some practice problems in Linkage analysis.

2. A diploid was sporulated and tetrads dissected and plated. The image below shows six tetrads plated on YPD (left) and dropout media (SC –leucine, right). Note that each row (A-F) represents one tetrad.

Based on this data, what percent of the colonies are Ade+ Leu+?

If you are having trouble with this question, try some practice problems in Linkage analysis.

Solution

1. you mate two haploid strains of the following genotypes

Strain 1: ADE2 HIS4                 Strain 2: ade2 his4

The resulting diploid is sporulated and equal numbers of spores are plated onto different media. You collect the following data:

150 colonies on YPD

75 colonies on SC -adenine

63 colonies on SC -adenine -histidine

Based on this data, what is the genetic distance between ADE2 and HIS4?

ANS: 16cm

2. A diploid was sporulated and tetrads dissected and plated. The image below shows six tetrads plated on YPD (left) and dropout media (SC –leucine, right). Note that each row (A-F) represents one tetrad.what percent of the colonies are Ade+ Leu+?

ANS: 33 %