In Mendel's dihybrid cross,what is the ratio of offspring possessing homozygous dominant and homozygous recessive genotypes in the $F_2$ generation,which shows a phenotypic ratio of $9:3:3:1$?

In a plant with genotype $RrYy$,if self-pollination occurs,what will be the ratio of the following genotypes: $RRYY, RrYY, RRYy, RrYy$?

$A$ trihybrid cross involves three pairs of traits,which gives an $F_1$ hybrid that is heterozygous for three genes. How many types of gametes will be produced in both male and female?

$F_{1}$ progeny of a Mendelian dihybrid cross produces:

$A$ dihybrid plant produced by self-pollination yields $400$ seeds with $9$ different genotypes. How many seeds will have the $TtRr$ genotype?

In a dihybrid cross,considering the characteristics of the $F_1$ generation obtained from the parental generation and the $F_2$ generation,how many types of gametes (pollen grains) will be produced by the $F_1$ generation?