POLYHYBRIDS

IV. POLYHYBRID CROSSES - When a cross involves working with >2 Genes at a time.

......Example:
..................P.........................AabbCcDDEe   X   AaBbCCddEe

..................F1  What are the odds of obtaining the following offspring:

1. aabbCCDdEe?   Figure the odds for getting each Gene's Genotype and multiply.  So,

A Gene (aa)  odds are 1/4
B Gene (bb) odds are 1/2
C Gene (CC) odds are 1/2
D Gene (Dd)  odds are 1/1
E Gene (Ee)  odds are 2/4 or 1/2

Now multiply:  1/4  x  1/2  x  1/2  x. 1/1  x 1/2  = 1/32

2. One with all of the Dominant traits: So A_B_C_D_E_
A_ = 3/4
B_ = 1/2
C_ = 1/1
D_ = 1/1
E_ = 3/4

So:  3/4  x  1/2  x  1/1  x  1/1  x  3/4  =  9/16