Experimental Lab 8: Mitotic Cell Divison
The objective of this experiment is to familiarize the student with the recognizing and identifying different types of cellular division in plant and animal cells. All cellular division in in eukaryotes undergoes DNA replication, nuclear division, and cytokinesis. In mitosis, one haploid cell is converted into two identical haploid cells. However in meiosis, two diploid cells divide into four haploid cells. In this experiment we will observe and identify the four stages of mitosis, including prophase, metaphase, anaphase, and telophase, and which stage the cell spends most of its time in.
Materials and Methods
The detailed procedure and list of materials can be found in pages 82-96 of the Biology 203L Lab Manual. No modifications or changes were made to the procedures.
There are many similarities and differences that we observed and know between meiosis and mitosis. First, mitosis produces two identical haploid cells from one haploid cell. In contrast, meiosis produces four non-identical haploid cells from one diploid cell. Similarly, each process goes through the main stages of the cellular division cycle, including DNA replication, nuclear division, and cytokinesis. In mitosis, the first stages of prophase, anaphase, metaphase, and telophase all appear similar to meiosis. In order to see the different stages of cellular division, a researcher would have to stain the chromosomes of the cell, as they are the information being replicated and divided to create new cells. If I were to design an experiment to study the cell cycle, I would take reproductive organ cells from an animal and study the process of meiosis. Mutations typically occur in prophase I when the chromosomes undergo crossing over.
The main purpose of gel electrophoresis is to separate different macromolecules to identify specific bands in DNA and RNA samples as well as compare samples together. In the gel, the different molecules move at different rates through the agarose, similar to how the different solutions of sodium chloride moved through the agar solution at different rates in experiment five. Smaller molecules will move quicker through the gel as the electrical current runs from top to the bottom, aiding the movement of the segments. In our experiment, DNA from different suspects was collected and ran through a gel electrophoresis to compare to the crime scene data. We observed the gel (pictured below) and concluded that the crime scene DNA (column 3) best replicates the DNA from Hannibal (column 5). Therefore, Hannibal must be the culprit of the crime.