Basic Genetics:The Cell, Mitosis and Meiosis, and Mendelian Laws

The cell is a basic unit of structure and function in a living organism. The living world consists of prokaryotic cells, which possess a circular genome without a nucleus, and eukaryotic cells, which contain their genome in individual chromosomes in a nucleus and have a well-organized internal structure. Information on the development and specific functions of cells and tissues is stored in the genes. Mitosis is the process by which the cell nucleus divides, resulting in daughter cells that contain the same amount of genetic material as the parent cell. Meiosis is a two-stage cell division in eukaryotes resulting in gametes with one-half the number of chromosomes in the parent cell. The inheritance of human variations follows Mendel's laws of segregation and independent assortment. In this chapter, the basics of cell biology and Mendelian inheritance are covered.