Pre-Lab Questions
1. Compare and contrast mitosis and meiosis.
2. What major event occurs during interphase?
Experiment 1: Following Chromosomal DNA Movement through Meiosis
Post-Lab Questions
1. What is the ploidy of the DNA at the end of meiosis I? What about at the end of meiosis II?
2. How are meiosis I and meiosis II different?
3. Why do you use non-sister chromatids to demonstrate crossing over?
4. What combinations of alleles could result from a crossover between BD and bd chromosomes?
5. How many chromosomes were present when meiosis I started?
6. How many nuclei are present at the end of meiosis II? How many chromosomes are in each?
7. Identify two ways that meiosis contributes to genetic recombination.
8. Why is it necessary to reduce the number of chromosomes in gametes, but not in other cells?
9. Blue whales have 44 chromosomes in every cell. Determine how many chromosomes you would expect to find in the following:
Sperm Cell:
Egg Cell:
Daughter Cell from Mitosis:
Daughter Cell from Meiosis II:
10. Research and find a disease that is caused by chromosomal mutations. When does the mutation occur? What chromosomes are affected? What are the consequences?
11. Diagram what would happen if sexual reproduction took place for four generations using diploid (2n) cells.
Experiment 2: The Importance of Cell Cycle Control
Some environmental factors can cause genetic mutations which result in a lack of proper cell cycle control (mitosis). 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 complete set of diploid chromosomes in a single cell.
Post-Lab Questions
1. Record your hypothesis from Step 1 in the Procedure section here.
2. What do your results indicate about cell cycle control?
3. Suppose a person developed a mutation in a somatic cell which diminishes the performance of the body's natural cell cycle control proteins. This mutation resulted in cancer, but was effectively treated with a cocktail of cancer-fighting techniques. Is it possible for this person's future children to inherit this cancer-causing mutation? Be specific when you explain why or why not.
4. Why do cells which lack cell cycle control exhibit karyotypes which look physically different than cells with normal cell cycle.
5. What are HeLa cells? Why are HeLa cells appropriate for this experiment?