Module 5 Cell Division

3.5.1 page 5

Lesson Summary

During this lesson you explored the following focusing questions:

• What kinds of cell division exist and when are they used?
• What are the structures that pass genetic information to the next generation and how are they observed?

Mitosis and meiosis are the main types of cellular division. Most of what we can see or observe around us is an example of mitotic growth or repair. Perhaps that is because it is fast and accurate. However, in later lessons, as you consider the survival of a species and the changing environmental pressures all life must face, you will soon see the value of meiotic reproduction.

In either type, DNA organized into chromosomes is at the heart of proper cell replication. In humans there are 22 pairs of autosomal chromosomes and a sex pair that determines gender. Together all 46 chromosomes must be duplicated and then passed on to each new daughter cell for those cells to carry on their roles. Chromosomes can be stained and arranged in a karyotpe so scientists can determine the health and gender of a young developing fetus.