Lab-7-Mitosis-Meiosis-Lab-Worksheet

Railey Sullivan BSC 108 Lab 7: Mitosis and Meiosis Lab Worksheet Mitosis and Meiosis Lab Instructions: Answer the questions below, based on Experiments 1 - 3. You do not need to submit any of your labeled images for this lab. Experiment 1 - Mitosis in Onion Root Cells Using information in the Background of the lab and your textbook, describe the features that are characteristic to each phase of the cell cycle in the plant cells (onion cells). Features in Onion Root Tip Cells Interphase Nucleus apparent, appears solid and dark, no chromosomes visible Prophase Nucleus fading, dark fractures seen and chromosomes visible Metaphase Spindles are easily identified Anaphase Separation of spindles are not long, separate into two entities Telophase Two separate nuclei and a dividing cell wall With the 100X objective lens, observe 5 columns of cells across and 20 rows of cells down of your onion root tip. This represents a random sample of 100 cells on the slide. Fill in the following blank table with initials for the phases of the cell cycle each cell you observe is in. I = Interphase, P = Prophase, M = Metaphase, A = Anaphase, T = Telophase Count the number of cells in each phase in your table and write them in the following table. To calculate the relative time spent in each phase: Count the number of cells you identified in each phase of the cell cycle. Use the following equation: relative time spent in phase = number of cells in phase / 100 Phase of Cell Cycle Number of Cells Relative Amount of Time Spent in Phase (%) Page 1 | 4 I M I I I I I I I I I P I I I I I I I A I I I I I T I I I I I I I A I I I P I I I M I I A M I I I I I I I I I I I P I I I I I M I P I I I I I I I I I M I I I T I I P A I

Click or tap here to enter text. BSC 108 Lab 7: Mitosis and Meiosis Lab Worksheet Interphase 72 70% Prophase 6 12% Metaphase 5 8% Anaphase 4 6% Telophase 3 4% Experiment 2 - Mitosis in a Whitefish Blastula Describe the features that are characteristic to each phase of the cell cycle in the fish embryo. You do not need to submit any of your labeled images for this lab. Features in Whitefish Blastula Interphase Microtubules arrays seen extending from chromosome, DNA and centrioles replicate Prophase Nuclei disappears, mitotic spindle forms pushing centrioles away from center, kinetochores pull chromosomes towards center Metaphase Chromosomes cluster at center Anaphase Chromosomes split Telophase Nuclei reappears, cytokinesis completes division Experiment 3 – Live Mitosis in Cultured Mammalian Cells Watch the Mitosis video. How does it compare to the static images? Record your observations here. Click or tap here to enter text. Mitosis and Meiosis Lab Instructions: Answer the questions below, based on Experiments 1 - 3. 1. Why is it appropriate to view a whitefish cell from a blastula in early embryonic development instead of a cell from adult tissue? most cells are constantly dividing, and therefore have large chromatids that are easier to see 2. Why must you observe the onion root tip instead of the main body of the onion? Page 2 | 4

Click or tap here to enter text. BSC 108 Lab 7: Mitosis and Meiosis Lab Worksheet phase of the cell cycle would you observe between the two slides? the cell structures would be different. Normal human cells have a large cytoplasm, single nucleus, and a smooth chromatid, while cancerous cells have a smaller cytoplasm, multiple nuclei, and a rough chromatid Page 4 | 4