Question

how I remember the dihybrid cross chart

Answer 1

A dihybrid cross is an experiment in genetics in which the phenotypes of two genes are followed through the mating of individuals carrying multiple alleles at those gene loci. Most sexually reproducing organisms carry two copies of each gene, allowing them to carry two different alleles.

the chart are the gametes produced by the mother. The mother and father are both dihybrids, “RrYy”. This means that after the process of gametogenesis, they will have produced the same gametes. The two cells at the top of the chart represent two diploid cells, as they enter meiosis. The two pathways shown highlight how eight different combinations can be created with these two cells. The left pathway shows how individual alleles are segregated into their own gametes after being replicated during meiosis I, then separated during meiosis II. The right side pathway shows the same thing, with the additional rearrangement of the parental genes. This is known as independent assortment, and also accounts for the variety created by sexual reproduction.

Hope it is helpful...

Answer 2

U need not to remember the chart just remember its ratio
That is 1:2:1:2:4:2:1:2:1