The dihybrid cross is associated with the principle of . . . . . . .

What is the phenotypic ratio of a test cross in the $F_1$ generation of a dihybrid cross?

The ratio $1:1:1:1$ is observed in:

In a cross between yellow round $(YYRR)$ and pure breeding pea plants having green wrinkled $(yyrr)$ seeds,find out the total number of seeds (plants) having yellow colour in the $F_2$ generation out of $16$ offspring.

$A$ cross between two pea plants,tall with axial flowers and dwarf with terminal flowers,produced offspring that were tall with axial flowers and tall with terminal flowers in the ratio $1:1$. What will be the genotype of the parents?

When a dihybrid plant with dominant traits of red color and tall height $(RrTt)$ is crossed with a recessive plant having white color and dwarf height $(rrtt)$,what will be the phenotypic ratio of the offspring for red-tall,red-dwarf,white-tall,and white-dwarf respectively?