Table 1: Record your data for the number of cells in each stage of the cell cycle observed in normal tissues.
Tissue Type # Cells in Interphase # Cells in Prophase # Cells in
Metaphase # Cells in Anaphase # Cells in
Telophase
Lung Tissue
Sample 1 19 1 0 0 0
Lung Tissue
Sample 2 19 0 0 1 0
Stomach Tissue
Sample 1 16 1 1 0 2
Stomach Tissue
Sample 2 18 0 1 1 0
Ovarian Tissue
Sample 1 18 0 1 2 0
Ovarian Tissue
Sample 2 18 0 1 2 0
Table 2: Record your data for the number of cells in each stage of the cell cycle observed in cancerous tissues.
Tissue Type # Cells in Interphase # Cells in Prophase # Cells in
Metaphase # Cells in Anaphase # Cells in
Telophase
Lung Tissue
Sample 1 15 1 3 0 1
Lung Tissue
Sample 2 16 0 2 1 1
Stomach Tissue
Sample 1 13 2 2 2 1
Stomach Tissue
Sample 2 14 2 1 1 2
Ovarian Tissue
Sample 1 12 2 1 2 3
Ovarian Tissue
Sample 2 11 2 2 3 2
Table 3: Use the data in Table 1 to calculate the Mitotic Index (average % cells dividing = # Cells in Prophase + Metaphase + Anaphase + Telophase divided by the Total Number of Cells times 100) for each normal tissue type.
Tissue Type Avg. % cells at rest
(average % cells in Interphase) Mitotic Index
(average % cells dividing)
Lung - normal 95% 5%
Stomach - normal
Ovary - normal
Table 4: Use the data in Table 2 to calculate the average % cells dividing and average % cells at rest in each cancerous tissue type.
Tissue Type Avg. % cells at rest
(average % cells in Interphase) Mitotic Index
(average % cells dividing)
Lung - cancerous ?? ??
Stomach - cancerous 67.5% 32.5%
Ovary - cancerous
Questions:
1. What does your data indicate about the rate of cell division in cancerous tissue compared to the rate of cell division in normal tissue? What data did you use to answer this question?
2. Which type of cancer is the fastest growing? Explain your answer, using your relevant data.
3. With what you have observed in this lab, if you were to compare tissue sample from normal breast tissue and cancerous breast tissue:
a. Would you expect to see a difference in the rate of cell division in the cancerous breast tissue compared to the normal breast tissue? Explain your answer.
b. Could you make a prediction about the average % dividing cells in the cancerous breast tissue? Explain your answer.
4. Consider the % dividing cells in normal lung, normal stomach, and normal ovarian tissue. Why do you think there are more cells dividing in the stomach and ovary tissue than in the lung tissue?
7. This lab explores three common cancers. An additional form of cancer – Skin Cancer – used to be seen only in older individuals but is now seen in younger individuals, many in their early 20s. Skin cancer results from accumulated mutations to the DNA of skin cells, caused primarily by sun exposure. What factors do you think may be contributing to the increase in skin cancer among young adults?