Although Mendel did not know that random orientation of homologous chromosome pairs during metaphase I leads to random allele combinations of different genes in gametes, he created the law of , which deduced this phenomenon.

The law you're referring to is Mendel's Law of Independent Assortment. This law states that the alleles for separate traits are passed independently of one another from parents to offspring. Here are the steps that led Mendel to this conclusion:

1. Mendel conducted experiments with pea plants, studying seven different traits, each with two contrasting forms. He cross-fertilized purebred plants with contrasting traits and observed the offspring.

2. In the first generation (F1), all offspring exhibited one of the two traits. This led to his Law of Dominance, which states that one allele (dominant) can mask the presence of another (recessive).

3. He then allowed the F1 generation to self-fertilize and produce a second generation (F2). In this generation, both traits appeared, but not in the same 1:1 ratio. Instead, the ratio was closer to 3:1, favoring the dominant trait.

4. Mendel repeated these experiments for all seven traits and consistently found the same 3:1 ratio in the F2 generation. This led to his Law of Segregation, which states that allele pairs separate during gamete formation.

5. Finally, Mendel conducted dihybrid crosses, which involve two traits. He found that the inheritance of one trait did not affect the inheritance of another, leading to his Law of Independent Assortment. This law states that genes for different traits can segregate independently during the formation of gametes.

6. Although Mendel did not know about chromosomes or meiosis, his laws are consistent with the process of meiosis, where homologous chromosomes separate independently during Metaphase I, leading to the random assortment of alleles in gametes.