Sexual Reproduction

Anotacoes

Sexual Reproduction and Genetics THE BENEFITS OF SEX MEIOSIS AND FERTILIZATION MENDEL AND THE LAWS OF INHERITANCE GENETICS AS AN EXPERIMENTAL TOOL EXPLORING HUMAN GENETICS Individual cells reproduce by replicating their DNA and dividing in two. This basic process of cell proliferation occurs in all living species—in the cells of multicellular organisms and in free-living cells such as bacteria and yeasts—and it allows each cell to pass on its genetic information to future generations. Yet reproduction in a multicellular organism—in a fish or a fly, a person or a plant—is a much more complicated affair. It entails elaborate devel- opmental cycles, in which all of the organism’s cells, tissues, and organs must be generated afresh from a single cell. This starter cell is no ordi- nary cell. It has a very peculiar origin: for most animal and plant species, the single cell from which an organism arises is produced by the union of a pair of cells that hail from two completely separate individuals—a mother and a father. As a result of this cell fusion—a central event in sexual reproduction—two genomes merge to form the genome of a new individual. The mechanisms that govern genetic inherit...