What phenotypic ratio is expected when a double heterozygote
     What phenotypic ratio is expected when a double heterozygote in the cis configuration is crossed with a double heterozygote in the trans configuration and the gene are tightly linked?  3:1  1:1  |2:1:1  1:1:1:1  9:3:3:1    
 
  
  Solution
Answer:
b. 1:1
Explanation:
AB/AB (Cis) X Ab/aB (Trans)
Ab
aB
AB
AB/Ab
AB/aB
1:1
| Ab | aB | |
| AB | AB/Ab | AB/aB | 

