Advanced Placement (AP) Biology Practice Exam

What is the term for the offspring resulting from the cross of two true-breeding parents?

1. F2 generation

2. P generation

3. Hybridization

4. F1 generation

The correct answer is: Hybridization

The term for the offspring resulting from the cross of two true-breeding parents is referred to as the F1 generation. When true-breeding individuals (homozygous for a trait) are crossed, the first generation of offspring produced is the F1 generation. This generation typically exhibits a uniform phenotype that reflects the dominant trait of the parents. In contrast, hybridization can refer to the process of breeding two different varieties or species, which is broader than simply crossing true-breeding parents. The P generation denotes the original parent generation from which the F1 generation is derived, while the F2 generation refers to the offspring produced when F1 individuals are crossed among themselves or self-fertilized. Therefore, the correct terminology for the offspring of the cross between two true-breeding parents is the F1 generation, highlighting the context of Mendelian genetics.