Question

Example Problem 2 A plant has fruits where green is dominant to blue, and hairy is dominant to waxy. The genes for color and texture are on the same chromosome, and have a recombination frequency of 14%. True breeding green, waxy plants are crossed with true breeding blue, hairy plants. The F1 is test-crossed with a blue and waxy plant. What are the expected genotypes, phenotypes, and phenotype proportions of the test-cross progeny?

Answer 1

Hene the recombination frequency is 147, means the genes are linked. They will not assort independently Now let Green gene= A Blue = a - Hairy B. Waxy= b.. -2 alleles of B. So True breeding Green, waxy plant = AA GB 2 alleles of A True breeding Blue, Hairy plant = aa bb. Imked The true breeding Green Werthely plant will only produce gamede - ĀB and u u u Blue waxy a u u u u=ab. - CARB genes are linked sola So, in F, all the eb). progeny will be ĀB ab with test cross with blue waxy plant aa bb. The fi will give gamates = AB or ab Test blue waxy plant will give germate - ab I ab l ab . AB AB ab AB ab as abas abab & genotype of test cross progeny = AB ab, abab on Phenotype u " u u = Green Hairy, Blue waxy The phenotypic proportion = 1:1. est