Why are chromosomes duplicated before mitosis

During prophase, the nucleus of the mother cell breaks away, exposing the chromatids. In metaphase, the chromatids line up along the center of the cell and the microtubules attach to them. The microtubules then pull the chromatids apart in anaphase. During the final phase of mitosis, telophase, the cell pinches in two and each daughter cell forms a nucleus around its complete set of chromosomes.

Mitosis only occurs in somatic cells -- the cells that make up the body. Gametes -- the egg or sperm cells that fuse with reproductive cells of the opposite sex -- still replicate their chromosomes during the S phase, but undergo a double split in meiosis to end up with only half the chromosome package.

Based in Portland, Ore. Her articles have appeared in magazines such as "Herb Companion" and "Northwest Travel" and she is the author of six books.

Two Types of Cell Division Cycles. List the Steps of the Cell Cycle in Order. Here is your typical cell cycle: As shown here, DNA replicates during the S phase synthesis phase of interphase , which is not part of the mitotic phase. Related questions Why is the number of chromosomes an organisms has an even number?

Why are chromosomes important to heredity? Why is DNA called the blueprint of life? How do genes differ from chromosomes? How can chromosomes be damaged? How does DNA code for proteins? How are mitosis and meiosis different? What is anaphase? What is mitosis? What are kinetochores made of? See all questions in Mitosis. Impact of this question views around the world.