You are a geneticist hired by a company that breeds pet tige
     You are a geneticist hired by a company that breeds pet tigers for super-rich costumers who place orders for cubs with specific combinations of four different phenotypes. What is the probability of producing a cub that will phenotypically resemble either one of the two parents in the following three crosses?  Aa Bb Cc Dd x act bb cc dd  aa bb cc dd x AA BB CC DD  aa bb cc dd x aa bb cc dd 
  
  Solution
Answer:
1). Aa Bb Cc Dd x aa bb cc dd
Aa x aa = Aa (1/2), aa1/2)
Bb x bb = Bb (1/2), bb(1.2) of
Cc x cc = Cc(1/2), cc(1/2)
Dd x dd =Dd (1/2), dd(1/2)
The probability of Aa Bb Cc Dd = 1/2 * 1/2 * 1/2 * 1/2 = 1/16
The probability of aa bb cc dd = 1/2 * 1/2 * 1/2 * 1/2 = 1/16
2).
aa bb ac dd x AA BB CC DD
aa x AA = Aa
Bb x BB = Bb
cc x CC = Cc
dd x DD =Dd
The probability of AA BB CC DD = 0
The probability of aa bb cc dd = 0
3) aa bb cc dd x aa bb cc dd
All progeny are genotypically and phenotypically aa bb cc dd.

