What is Mendel's Crosses in genetics explain breifly?

Mendel found that if he transferred pollen from a green-seed strain to a yellow-seed strain and vice versa, in a process called cross-pollination, he could produce mixed or hybrid offspring. In the resulting first filial generation (F1), all plants had yellow seeds. For other traits as well, the plants showed either one or the other of the parents' traits, but never both. In other words, one trait was always dominant, and the other recessive. However, the following year, Mendel self-pollinated all of the F1 plants. He found that the recessive trait, that had apparently been lost in the F1 generation, reappeared in the second filial generation (F2). His observations showed that the ratio of dominant to recessive traits in the F2 generation was always about 3:1.

In later experiments, Mendel backcrossed hybrid F1 plants with the original P1 plants. When a hybrid was backrossed with the recessive parent, there was a 1:1 mixture of dominant and recessive traits in the offspring. This was in contrast to backcrosses with the dominant parent, which produced 100% of the dominant trait. Mendel inferred that traits are carried by pairs of determinants, called factors. We now name the determinants alleles, which are paired genes.

In diploid organisms, there is one allele for a particular trait from each parent. Organisms in which both parents carry the same trait homozygous, for either the dominant or the recessive trait. Organisms that carry both dominant and recessive traits are heterozygous. The genetic information determining traits is the genotype, while the physical appearance of the organism is the phenotype.