Q. In a typical Mendelian cross which is a dihybrid cross, one parent is homozygous for both dominant traits and another parent is homozygous for both recessive traits. In the $F_{2}$ generation, both parental combinations and recombinations appear. The phenotypic ratio of parental combinations to recombinations, is
A) 10:6
B) 12:4
C) 9:7
D) 15:1
Explanation
A cross of round yellow seeds (both dominant) and green wrinkled seed (both recessive) plants produced 9 : 3 : 3 : 1 ratio of plants (phenotypic)in F2 generation. The ratio of parental to recombinant is 10 : 6 here because the 9 and 1 are of parental type and 3 & 3 are recombinant.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.