How many types of gametes and in what ratio will be produced by a dihybrid heterozygote?

In the $F_2$ generation of a Mendelian dihybrid cross,how many plants homozygous for both the traits are found?

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

State the Law of Independent Assortment and explain how it is derived.

In a dihybrid cross,what is the proportion of $RrYy$ offspring obtained from the selfing of an $RrYy$ plant (in $/16$)?

$A$ pure breeding pea plant with round yellow seeds was crossed with a pea plant having wrinkled green seeds. On selfing of the $F_1$ hybrid of this cross,$64$ progenies were obtained in the $F_2$ generation. Find out the number of $F_2$ progenies showing non-parental characters.