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Virtual Lab: The Cell Cycle and Cancer Cell Reproduction Youtube link: https://youtu.be/0l-QKSALE-Y Purpose: In this investigation you will explore the similarities and difference between the cell cycles of normal cells and cancer cells. Objectives: · To identify the various phases of the cell cycle. · To compare and contrast the cell cycles of normal and cancer cells How can cancer cells be recognized? Following are some recent statistics for lung, ovarian, and stomach cancer (the figures are estimates by the American Cancer Society and National Cancer Society): Lung Cancer 1995 new cases-169 900 1995 deaths-157 400 Ovarian Cancer 1995 new cases-22 600 1995 deaths-14 500 Stomach Cancer 1996 new cases-28 800 1996 deaths-14 000 It is difficult for scientists to determine the exact causes of cancer because both environmental and genetic factors are involved. Scientists can, however, identify risk factors for particular types of cancer. Following are some of the risk factors associated with each of the three types of cancer we are investigating: Lung Cancer industrial substances, certain organic chemicals, and asbestos exposure to secondhand cigarette smoke Ovarian Cancer risk increases with age cigarette smoking exposure to radiation and/or radon exposure to women who have never had children are at a higher risk than those who have had children women who have had breast cancer or a family history of ovarian cancer are at increased risk certain rare genetic disorders are associated with increased risk Stomach Cancer risk increases over the age of 55 men are at a higher risk than women eating foods preserved by smoking, drying, salting or pickling is associated with increased risk Watch the YouTube Video: 1. First the TV/VCR will be turned on so that you will Watch the video about the cell cycle. 1. Be sure to review what you read about the cancer statistics and risk factors 1. During the YouTube the microscope in the lab simulation will allow you to examine the different stages of mitosis as they appear in different tissue samples. Three types of tissues are for examination: Lung, stomach, and ovary. Samples of normal tissue and cancerous tissue are included. Watch as the video clicks on the tissue box to examine different tissue type only. Follow the instructions to label each stage of the cell cycle. You will need to pause the video to do this. 1. Record the number of cells in each stage of the cell cycle in Table 1 for normal tissues and Table 2 for cancerous tissues. You must examine three different views of each tissue type and condition—view alternate samples of each tissue type until you have recorded the number of cells in each stage of the cell cycle for 3 different sample of each tissue. 1. Calculate the average Mitotic index (% cell dividing) and average % cells at rest for normal tissues. Record these numbers in Table 3 and 4 on your worksheet. To calculate the average % cells at rest in normal tissue 4. (# cells in Interphase in Sample 1 + # cells in Interphase in sample 2) = total # cells at rest 4. (total # cells at rest/total # cells in both samples) x 100 = average % cells at rest To calculate the Mitotic Index--average % cells dividing -vin normal tissue: 1. (# cells in mitosis in Sample 1 + # cells in mitosis in Sample 2)/2 = avg. # cells dividing 1. (avg. # cells dividing/total # cells) x 100 = average % cells dividing Table 1: 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 Lung Tissue Sample 2 Ovary Tissue Sample 1 Ovary Tissue Sample 2 Table 2: 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 Stomach Tissue Sample 1 Stomach Tissue Sample 2 Ovary Tissue Sample 1 Ovary Tissue Sample 2 Table 3: Mitotic Index (average % cells dividing) and Aver. % of cells at rest. Tissue Type Avg. % cells at rest Mitotic Index Stomach - normal Ovary - normal Table 4: Mitotic index (average % cells dividing) and Avg. % of cells at rest. Tissue Type Avg. % cells at rest Mitotic Index Stomach - cancerous Ovary - cancerous Summary Table: Number of Cells in Each Phase of the Cell Cycle interphase prophase Metaphase Anaphase Telophase Percentage of cells dividing Percentage of cells at rest Normal Lungs Cancerous Lungs Normal Stomach Normal Ovary Cancerous ovary Analysis 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? 1. With what you have observed in this lab, if you were to compare tissue sample from normal breast tissue and cancerous breast tissue: 1. 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. 1. Could you make a prediction about the average % dividing cells in the cancerous breast tissue? Explain your answer. 1. Based on your data and observations, what are some of the Differences between normal cells and cancer cells? 1. Which type of cancer shows the most aggressive growth? Explain. 1. When studying cell division in tissue samples, scientists often calculate a mitotic index, which is the ratio of dividing cells to the total number of cells in the sample. Scientists often calculate the mitotic index to compare the growth rates of different types of tissue. Which type of tissue would have a higher mitotic index, normal tissue or cancerous tissue? Explain. The Living Cell How can microscopic protists and fungi be characterized? Protists and fungi are vital in nearly every ecosystem on Earth. Protists release large amounts of oxygen into the atmosphere. They also absorb large amounts of carbon dioxide. Some protists have important medicinal value. Both protists and fungi serve as important links in the food chains of various ecosystems. Fungi play crucial roles as decomposers, breaking down decaying organisms and wastes. The protist kingdom is the most diverse of the six kingdoms of life. The protist kingdom is made up of more than 200,000 species. Some protists are one-celled organisms, while others are many -celled. Some protists have a means of locomotion, while others are not able to move from place to place. The one characteristic that all protists have in common is that they all are eukaryotic (have a nucleus). Protists can be organized into three general groups: animal-like protists, plantlike protists, and funguslike protists. Like protists, all fungi are eukaryotic and may be one-celled or many-celled. Only some fungi are able to move from place to place, and all fungi obtain food from other organisms. Most fungi feed on dead or decaying plant and animal tissues. Organisms that obtain food in this way are called saprophytes. Fungi that obtain food directly from living organisms are called parasites. Most fungi produce spores-reproductive cells that form new organisms without fertilization. When a spore is released and lands in a place that has all the conditions necessary for growth, the spore forms a new fungus. The structures in which fungi produce spores are used to classify fungi into one of four divisions: zygote fungi produce spores in round spore cases on the tips of the body of a fungus; sac fungi produce spores in a small sac called an ascus; club fungi produce spores in a club -shaped structure; imperfect fungi are those for which no sexual spore stage has been observed. In this Virtual Lab you will investigate different types of microscopic organisms from the protist and fungi kingdoms. You will examine magnified views of these organisms. Using information about their habitats, nutrition, and locomotion, you will classify each organism as an animal-like protist, plantlike protist, funguslike protist, or fungus. Objectives: Classify microscopic protists and fungi. Compare and contrast animal-like, plantlike, and funguslike protists as well as sac and zygote fungi. Watch the YouTube video. You will note that the a microscopic slide box will be clicked to get a magnified view of a protist or fungus. As each specimen is clicked: 1. Record the name of the organism in the Table below. 2. Read and Record the field notes to gather general information about the organism in the Table below. 3. Read and record the information about the organism's habitat in the Table below. 4. Read and record the information given from the Nutrition Tab in the Table below. Does the organism makes its own food or obtains it from another source? 5. Read and record the information obtained about the organisms Locomotion in the Table below (describe what you observe). 1-5 MUST BE FROM THE YOUTUBE LINK ONLY (NO GOOGLE SEARCHES) 6. Complete the Following questions. (if you research these be sure to cite and reference) a. Different type of protists moves in different ways. Describe how one of the protists you observed moves? b. Why are so many other living things dependent on plant-like protists? c. Which organisms could not move? Why d. Which of the protists you observed had both plantlike and animal-like characteristics? Why e. Explain why algae are plantlike f. Locomotion is generally a characteristic of animals. However, some plantlike protists move about by means of flagella. What is the adaptive advantage of a photosynthetic organism that is able to move from place to place? g. How do the fungi you identified obtain food? h. How are fungi important to the environment? i. If an imperfect fungus were found to produce spores in sexual reproduction. What would you need to look at to reclassify the fungus? j. Using the Youtube Video –what are the characteristics of Animal-like Protists? k. Using the Youtube Video –what are the characteristics