 Organisms have thousands of genes , and in sexually reproducing organisms these genes generally assort independently of each other . This means that the inheritance of an allele for yellow or green pea color is unrelated to the inheritance of alleles for white or purple flowers . This phenomenon , known as " Mendel 's second law " or the " Law of independent assortment " , means that the alleles of different genes get shuffled between parents to form offspring with many different combinations . ( Some genes do not assort independently , demonstrating genetic linkage , a topic discussed later in this article . ) 
