Q. Assume we have three linked genes, all of which control different aspects of the same phenotype. We perform a testcross of a triple heterozygote (a+b+c+/a b c) with a triply homozygous recessive (a b c/a b c) and then count the number of progeny in each of the phenotypic classes. There are a total of 550 progeny. Organize the genotype in the table, define the origin (parental, single cross-over progeny and double-crossover progeny) and find out the order of the genes on the chromosome.

a+b+c+ 200
a b+c+ 66
a+b c+ 19
a b c+ 5
a b c 180
a+ b c 54
a b+ c 20
a+b+ c 6

Want to know genotype of gamete from heterzygous parent, number, and orgin of each. Also the order of genes.