How to calculate pairings

How you calculate pairings?

How do you calculate in general the offspring of a pairing? We use the Punnet square. There are three steps:

  • Find the gametes the cock produces
  • Find the gametes the hen produces.
  • Calculate the offspring using the Punnet square. In the first row, write all the possible gametes of the cock. All the possible gametes of the should be written in the first column. Now all the possible combinations of gametes from the cock and the hen can easily be filled in. If you haven't right got it yet, don't worry. It will become clear after the example.
    COCK
    Gamete #1 Gamete #2 ...
    HEN
    Gamete #1      
    Gamete #2      
    ...
         
Note: Every possible gamete is formed with the same probability. Since chance is however involved in the fertilisation process, the observed genotypes from a pairing may deviate from the theoretical proportions.