Q. The ratio 1 : 1 : 1 : 1 is obtained from a cross between the parents
A) $RRYY \times rryy$
B) $RRYY \times rryy$
C) $RRYY \times Rryy$
D) $RrYy \times rryy$
Explanation
When the F1-hybrid (Rr Yy) of a dihybrid cross is test crossed (crossed with double recessive parent rryy), the F2-offspring appear in the phenotypic and genotypic ratio of 1 : 1 : 1 : 1 confirming that F1-offspring was heterozygous in both the traits. It is a cross between RrYy × rryy.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.