When predicting the genotype of the offspring in a genetic cross, what are the first set of parents called?

In genetic crosses, the first set of parents is referred to as the parental generation, often abbreviated as P. This generation provides the alleles through which the offspring inherit traits. In a typical genetic study, the parental generation is crossed to produce the first filial generation, known as the F1 generation. The F1 generation is then often interbred or crossed to produce the next generation, which is referred to as the F2 generation.

Understanding the hierarchy of these generations is critical in genetics, as it lays the foundation for predicting the phenotypic and genotypic ratios in offspring based on Mendelian inheritance patterns. The other terms, such as gametes, refer to the reproductive cells involved in fertilization, while filial generations pertain to subsequent generations after the parental generation. Thus, the designation of the parental generation (P) specifically highlights the initial source of genetic material in the study of inheritance.