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 $F_{1}$-hybrid (Rr Yy) of a dihybrid cross is test crossed (crossed with double recessive parent rryy), the $F_{2}$-offspring appear in the phenotypic and genotypic ratio of 1 : 1 : 1 : 1 confirming that $F_{1}$-offspring was heterozygous in both the traits. It is a cross between $RrYy \times rryy.$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.