Question

Please Show how to find the Expected values

A fully heterozygous flowering plant with normal green flowers and round seeds. This plant, when crossed with one that has purple flowers and oval seeds, results in the following progeny:

83 green, round

126 purple, round

117 green, oval

74 purple, oval

A. What is the recombination frequency between seed color and shape?  (show all work)

B. Do a Chi square test for linkage. Are these genes linked and if so are they linked “cis” or “trans”? (show all work)

Answer 1

A. Recombination frequency

+ total number of recombinants/total offsprings*100

= 83+74/400*100= 39.25%

B. expected number of all phenotypes will be 50 if genes are not linked and follow independent assortment since total number of offsprings is 200

(O-E)2/E

(83-50)2/50+ (74-50)2/50+ (126-50)2/50+ (117-50)2/50=

21.78+ 11.52+ 115.52 + 89.78

238.6

ch square value is much higher than what is in table for degree of freedom 3

so hypothesis is rejected . therefore two genes are linked together