Radishes have three phenotypes for shape (long, round, or oval) and three phenotypes for color (red, white or purple). if you cross a long/white radish with with a round/red one, all the offspring are oval/purple (F1). If you cross two oval/purple radishes, you find nine combinations of phenptypes (F2) as follows: 9 long/red; 15 long/purple; 19 oval/red; 32 oval/purple; 8 long/white; 16 round/purple; 8 round/white; 16 oval/white; and 9 round/red.
a.provide a genetic explanation of these results. be sure to define genotypes and show the genotypes of all individuals listed above (parents, F1, and F2).
b.predict the genotypic and phenotypic proportions in the offspring of a cross between a long/purple and an oval/purple radish.
If we run several crosses of the type: AA BB * aa bb, the F1 offspring should all be Aa Bb. If we then takes these F1 individuals and perform a testcross (mate them with an individual that has the genotype aa bb) we might obtain the following outcomes:
AaBb * aa bb Offspring
cross AaBb aa bb Aabb aaBb
#1 310 315 298 312
#2 36 38 35 39
#3 360 380 230 230
#4 74 72 78 69
For each set of offspring, use the Chi square test to decide if the data meets or deviates significantly from the expectation that these two genes are assorting independently.