About This Chapter
Take the most advanced computer today and it still won't compare to the complex yet elegant applications that take place on the cellular level. With three billion bases in the human genome, the DNA content in a single cell is a comprehensive cookbook containing recipes for life. You'll see how arrangements of chromatin, chromosomes, histones and nucleosomes allow this wealth of information to be packaged in a cell's nucleus. Still, how do we get from one cell to the trillions of cells that make up the human body?
Each cell in your body has a series of programmed events, known as the cell cycle, to keep you up and running. Much of the cell cycle is spent in preparation, and, from interphase to cytokinesis, we're going to show you how the cell cycle is just like decorating Christmas trees in the future. While this may sound crazy, just wait until we delve in to the intricacies of cell division. We'll come full circle as we journey through the cell cycle and see how replication leads to more replication.
We'll explore the exquisite machinery of mitosis, an entire process devoted to making sure that your DNA is properly preserved and packaged as cells divide. You'll also take a closer look at how the genome is organized into chromosomes and learn how to distinguish between homologs and chromatids. Line up along the equatorial plate and observe how centromeres, centrosomes, centrioles, kinetochores and the mitotic spindle bring it all together before pulling it apart at just the right moment.
We'll also journey from diploid cells to the haploid realm of gamete production, as we examine yet another type of cell division known as meiosis. Don't worry, many parts of the meiotic process are similar to mitosis, so we'll make sure that you understand those important differences, the crossover and recombination that occur. However, life isn't perfect, so we'll also explore the meiotic errors that can take place. By the end of our cell division section, you'll see how life propagates and how knowledge can lead to more knowledge.