All body cells have a short life span. To make sure organisms can continue to survive, they constantly need to make new copies of their cells. To do this they undergo a process of duplicating themselves. There are five phases associated with this process. The first phase is named Prophase. This is where the cell duplicates its DNA. The second phase is called Metaphase this is where the DNA lines up in the middle of the cell. The third phase is where the chromosomes (DNA) begins to split and move itself into two cells. During the Telophase, the cells actually pinch off into two separate beings. The final stage is really when nothing is going on and that phase is called Interphase. I refer to it as the in between phase. This process of cell self-replication of body cells is called mitosis. If this process takes place in a sex cell (sperm or egg) it is called meiosis. In mitosis the division only occurs once which creates two cells from one cell. As a result, both new cells are identical copies of the original cell. In meiosis the division occurs twice. So that single egg or sperm cell create four new cells that have only part of the original gametes genetic information. Therefore, sex cells are genetically diverse. This is also why the babies that sex cells form as genetic diverse too.
The worksheets work on identifying the different phases of mitosis visually as well as by description. We also look at the multiplying of body cells (mitosis) vs. the multiplying of sex cells (meiosis). These worksheets will begin by labelling and defining the function of all the phases of cell division. We will breakdown both mitosis and meiosis separately. We will also compare and contrast these cell regenerating processes. We will lead you on to performing your own lab investigation with these body cells. A fun thing to have students do is to slice an onion root tip super thinly and extract some cells to look at under a microscope. I find it easier to use green onions since they mostly have roots exposed. You can use regular white onions, but they are a little harder to see, unless you have the correct type of stain available for your slides.
