The pedigree below shows the inheritance pattern of Bt resis
     The pedigree below shows the inheritance pattern of Bt resistance in three generations of bollworms. How many individuals on this pedigree are definitely heterozygous (Rr)?  nine  eight  seven  six  five or fewer 
  
  Solution
the answer is seven because heterozygous means there are 2 different alleles for the same gene .As we can see the total number of different allele in third generation is 7(the number of circles and boxes).

