You cross a mutant with phenotype x y z to a mutant with the

You cross a mutant with phenotype \'x y z\" to a mutant with the phenotype \'x^+ y^+ z\' and _______/5 test cross the F1. Given this genetic map, predict the phenotypes observed in the offspring, and the number of each expected in a population of 2500 (show your work). x y z

Solution

Answer:

xx yy z⁺z⁺ X x⁺x⁺ y⁺y⁺ zz----------Paretnts

xyz⁺ x⁺y⁺z-------------gametes

x⁺x y⁺y z⁺z -------------(F1)

F1 x xx yy zz

map distance = % recombinants

F1 progeny produces the following ratio of gametes.

x⁺x y⁺y z⁺z

single cross over between x and y= xy⁺z and x⁺yz⁺ = 12% = 12/100 * 2500 = 300 (each gamet 150)

single cross over between y and z = xyz and  x⁺y⁺z^{+ = 24% = 24/100 * 2500 = 600}

Double cross overs =xy⁺z⁺andx⁺yz = 0.12 * 0.24 = 0.0288

Double cross over gametes = 0.0288 * 2500 = 72 (each 36)

Total recombinants = 300 + 600 + 72 = 972

Parental combinaitons = 2500 - 972 = 1528

Parental combinations = xyz⁺ and x⁺y⁺z , each 764

xxyyz⁺z = 764

x⁺xy⁺yzz= 764

xxy⁺yzz = 150

x⁺xyyz⁺z = 150

xxyyzz = 300

x⁺xy⁺yz⁺z = 300

xxy⁺yz⁺z = 36

x⁺xyyzz = 36