Dihybrid test cross ratio is

The correct option is B

1:1:1:1

The correct option is B.

The explanation for the correct option:

1. The Dihybrid test cross-ratio is 1:1:1:1.
2. A Dihybrid cross is a cross between two different genes having different characters.
3. Dihybrid test crossing is the cross in which one parent from F1 generation having heterozygous condition gets crossed with a parent which is double homozygous and recessive in nature. They are allowed to fertilize with each other.
4. It is used to test the linkage between the genes.

	Double heterozygous F1 Dihybrid	Double homozygous recessive plant
Type of Genotype	Yellow Round YyRr	Green wrinkled yyrr
Type of gametes	YR Yr yR yr	yr yr yr yr

Final answer: Dihybrid test-cross ratio is 1:1:1:1.