How many different types of gametes can be formed by $F_1$ progeny,resulting from the following cross: $AA BB CC \times aa bb cc$?

In Mendel's dihybrid cross,the number of genotypes and phenotypes obtained in the $F_2$ generation are $P$ and $Q$ respectively. Identify $P$ and $Q$.

In peas,tallness is dominant over dwarfness and red colour of flowers is dominant over the white colour. When a tall plant bearing red flowers was pollinated with a dwarf plant bearing white flowers,the different phenotypic groups were obtained in the progeny in numbers mentioned against them:
Tall,Red $= 138$
Tall,White $= 132$
Dwarf,Red $= 136$
Dwarf,White $= 128$
Mention the genotypes of the two parents and of the four offspring types.

The phenotypic ratio in the $F_{2}$ generation of a dihybrid cross is

Describe the inheritance of two genes.

How many pairs of chromosomes are involved in Mendelian dihybrid crosses and dihybrid crosses with linkage,respectively?