Experiment 1: Following Chromosomal DNA Movement through Meiosis Experiment 1: Following Chromosomal DNA Movement through Meiosis

215

Mitosis and Meiosis

Experiment 5: The Importance of Cell Cycle Control

Some environmental factors can cause genetic mutations which result in a lack of proper cell cycle control. When this happens, the possibility for uncontrolled cell growth occurs. In some instances, uncontrolled growth can lead to tumors, which are often associated with cancer, or other biological diseases.

In this experiment, you will review some of the karyotypic differences which can be observed when comparing normal, controlled cell growth and abnormal, uncontrolled cell growth. A karyotype is an image of the com- plete set of diploid chromosomes in a single cell.

Procedure:

1. Begin by constructing a hypothesis to explain what differences you might observe when comparing the karyotypes of human cells which experience normal cell cycle control versus cancerous cells (which expe- rience abnormal, or a lack of, cell cycle control). Record your hypothesis in Post-Lab Question 1.

Note: Be sure to include what you expect to observe, and why you think you will observe these fea- tures. Think about what you know about cancerous cell growth to help construct this information

2. Go online to find some images of abnormal karyotypes, and normal karyotypes. The best results will come from search terms such as “abnormal karyotype”, “HeLa cells”, “normal karyotype”, “abnormal chromo- somes”, etc. Be sure to use dependable resources which have been peer-reviewed!

3. Identify at least five abnormalities in the abnormal images, and list them in the Data section at the end of this experiment. Do these abnormalities agree with your original hypothesis?

Hint: It may be helpful to count the number of chromosomes, count the number of pairs, compare the sizes of homologous chromosomes, look for any missing or additional genetic markers/flags, etc.

Materials

*Computer Access

*Internet Access

*You Must Provide