In cross between pure breeding pea plants having yellow round (YYRR) and green wrinkled (yyrr) seeds, find out the total seeds (plants) having yellow colour in F₂ -generation.

A cross between pure yellow round seeded plants and pure green wrinkled seeded plants is shown below
 

Round yellow : Round green : wrinkled yellow : wrinkled green
         9            :           3         :             3           :             1
Thus, the number of plants of F₂-generation having yellow coloured seeds are 12 (out of 16).