The purpose of this lab was to recognize the stages as well as events of mitosis and meiosis in a plant cell or an animal cell. The relative duration of each stage in the cell cycle will also be learned during this lab. By doing this lab we will also create a model of and understand the process of crossing over. This lab also helps students understand the similarities along with differences between mitosis and meiosis.
I predict that interphase will be the longest phase because many events such as a cell growth and chromosome replication occur during interphase, which I believe, would be a long process. I also think that the frequency of crossing over is affected by the distance between genes. I believe that mitosis and meiosis have very clear differences such as in the cells produced. I think that recognizing the stages of mitosis within our onion cell will be relatively easy.
My hypothesis proved to be correct for the part. Recognizing the stages of mitosis was not as easy as expected. There were many cells and we had to look for key features of each stage. For example, we identified a cell in metaphase because we noticed that the chromosomes seemed to be lined up at the center. As can be seen on table 3.1 on page 34 of the lab interphase was occurring in the most number of cells for each field of the onion root tip. Most of the cells were in interphase; therefore, interphase is the longest stage. The next largest group was prophase, indicating this phase is the second longest. The three remaining were close in number but varied which indicated that all those stages happen quickly. The frequency of a crossover occurring between two particular genes on the same chromosome increases as the distance between those genes becomes larger. The frequency of crossover therefore, appears to...