During the past 100 years, the growth in human populations in the urban areas of industrialized nations has greatly contributed to all BUT one of these environmental problems

"a.) well–developed vascular system."

the principle of segregation describes how pairs of gene variants are separated into reproductive cells. from his data, mendel formulated the principle of segregation. we now know that the segregation of genes occurs during meiosis in eukaryotes, which is a process that produces reproductive cells called gametes.