Biology

The correct answer is B. Law of Segregation.

The statement "During meiosis and gamete formation, homologous (paired up) alleles split up" is related to the concept known as the Law of Segregation, which is a fundamental principle of inheritance discovered by Gregor Mendel.

The Law of Segregation states that during gamete formation (meiosis), the two alleles for a trait present in an individual separate or segregate from each other, so that each gamete receives only one allele for that trait. This separation ensures that each gamete carries only one copy of each allele.

In the context of the given statement, during meiosis, when homologous chromosomes pair up, the alleles located on these homologous chromosomes separate during the process of homologous recombination and independent assortment. As a result, the gametes produced will carry only one allele for each trait.