Organisms with the genotypes aaBbCcDd and AaBbCcDd are cross

Organisms with the genotypes aaBbCcDd and AaBbCcDd are crossed. What are the expected proportions of the following progeny? A-B-C-D- AabbCcDd A phenotype identical to either parent A-3-ccdd

Solution

aaBbCcDd x AaBbCcDd ============> It is based on multiplicative or and law of probability. The individual proportions are: aa x Aa ----------> 1/2 of Aa & 1/2 of aa.

Bb x Bb ------------> 1/4 of BB, 1/2 of Bb & 1/4 of bb

Cc x Cc -------------> 1/4 of CC, 1/2 of Cc & 1/4 of cc

Dd x Dd --------------> 1/4 of DD, 1/2 of Dd & 1/4 of dd

Then

a. A----B---C---D--. It is AaBbCcDd. Its proportion is 1/2 x 1/2 x 1/2 x 1/2 = 1/16

b. 1/2 x 1/4 x 1/2 x 1/2 = 1/32

c. Proportion of AaBbCcDd is 1/16 & proportion of aaBbCcDd = 1/16

d. 1/2 x 1/2 x 1/4 x 1/4 = 1/64