Final answer:
Alleles are separated during the first division of meiosis, where homologous chromosomes segregate. This process follows Mendel's principle of segregation, which states that each gamete would carry only one allele for each trait, in line with the observed inheritance patterns.
Step-by-step explanation:
The two alleles for a given trait are separated during the first division of meiosis, when homologous chromosomes segregate into daughter nuclei.
Mendel's first law, the principle of segregation, elucidates the separation of pairs of alleles as gametes are formed. This fundamental biological process occurs during meiosis, a type of cell division that results in four daughter cells, each with half the number of chromosomes of the parent cell. Specifically, it is during the first meiotic division that the segregation of homologous chromosomes takes place, and as a result, alleles are separated. This leads to each gamete carrying only one allele for each trait, ensuring genetic diversity through sexual reproduction.
The law of segregation helps us understand why organisms inherit one allele for each trait from each parent. Mendel observed this pattern in his experiments with pea plants, where traits were passed down in specific ratios. This discovery laid the groundwork for genetics, allowing us to predict genotypic and phenotypic outcomes using tools like the Punnett square. Although Mendel did not know about chromosomes and meiosis, his work correlates with what we now comprehend about chromosomal behavior during meiosis and its impact on inheritance.