3.01 Cell Cycle Lab Report Safety Notes: Always handle microscopes and glass slides carefully. Wash your hands after handling the prepared specimens. Materials: o o Compound light microscope Glass microscope slide with prepared onion root tip specimen Purpose: understand and identify the stages of the cell cycle and mitosis. apply an analytical technique to estimate the relative length of each stage of the cell cycle. Hypothesis: What do you predict you will find about the number of cells in each of the phases of the cell cycle? I think I will find that most of them are in interphase. This is because it is the longest cycle. Provide an explanation for your prediction. Procedure: Data and Observations: Create a data table containing a tally of the number of cells observed in each of the following stages: Number Number of Cells of Cells Stage in Part in Part 1 2 Interphase 34 49 Prophase 8 13 Metaphase 3 4 Anaphase 2 3 Telophase 2 4 Cytokinesis 1 3 Record any observations about the cells you observed (what does the cell look like for each stage): Interphase was just a cell with squiggly lines. Prophase had a bunch of X’s in no particular order. Metaphase had a couple of X’s in the center with lines on the left and righ sides going across, but no lines in the middle. Anaphase had the X split in half, and half of the X’s on one side and the other half on the other side with the lines still there. Telophase was 2 cells split, and cytokinesis was those 2 cells with a line between them. Data Analysis: Calculate the percentage of the cell cycle spent in each stage. Number of cells in given stage ÷ total number of cells counted × 100 = % of the cell cycle spent in this stage Create a graph that represents the time spent in each stage of the cell cycle. 80% 70% 60% 50% Part 1 40% Part 2 30% 20% 10% 0% Interphase Prophase Metaphase Anaphase Telophase Cytokinesis Conclusion: Be sure to answer the following reflection questions in the conclusion of your lab report: 1. Based on your data, what can you infer about the length of time spent in each stage of the cell cycle? 2. What stages were the longest and shortest? The Interphase is the longest cycle, and Anaphase seems to be the shortest. Give a brief explanation of why these stages may have that time period. During Interphase, the cell needs to grow which does take a while. 3. What is a distinguishing visible feature of each stage of the cell cycle? 4. What differences can you see when you compare the nucleus of a dividing cell with that of a nondividing cell? 5. If your observation had not been restricted to the tip of the onion root, how would the results be different?