What is the expected outcome of a cross between two homozygous individuals with contrasting traits?

When two homozygous individuals with contrasting traits are crossed, the expected outcome is that all offspring will express the dominant trait. This stems from the principles of Mendelian genetics, where a homozygous individual contains two identical alleles for a trait, either dominant or recessive.

For example, in a cross between a homozygous dominant individual (AA) and a homozygous recessive individual (aa), all offspring (F1 generation) will receive one dominant allele from the homozygous dominant parent and one recessive allele from the homozygous recessive parent, resulting in offspring that are all heterozygous (Aa). Since the dominant allele masks the expression of the recessive allele, all offspring will express the dominant trait.

This outcome contrasts with other possible ratios that could occur in different types of genetic crosses. The 1:2:1 ratio typically applies to the offspring of a heterozygous cross (Aa x Aa), where you would see a mix of homozygous and heterozygous individuals. Similarly, the 3:1 ratio applies to the phenotypic ratio of offspring resulting from a heterozygous cross (for example, Aa x Aa), where three individuals show the dominant trait