Mitosis Lab Report

In a cell cycle, there are specific checkpoints between each phases caused by the occurrence of cyclin. Cyclin determines how concentration flunctuatues. If the regulation is disrupted by a decreasein cyclin, there would be no mitosis, meaning the cell cycle would continuously go thre G0 phase. However, if there is an increase

Exercise 3A is a study of mitosis. You will simulate the stages of mitosis by using chromosome models.You will use prepared slides of onion root tips to study plant mitosis and to calculate the relative duration of the phases of mitosis in the meristem of root tissue. Prepared slides of the whitefish blastula will be used to study mitosis in animal cells and to compare animal mitosis and plant mitosis.

In this experiment first the stages of an onion cell undergoing mitosis are going to be observed and every stage is going to be detected and drawn on paper. A brief description to what is going on should be attached to the pictures. This is important to understand the basics of cell division which is necessary growth,repair and asexual reproduction. Second the number of cells undergoing each phase is going to be counted to figure out in which phase the cell remains the most. If interphase is the stage in which the cell grows and prepares for cell division then the

Purpose: The purpose of this lab was to calculate the amount of time that was spent by a cell in each of the phases of mitosis. Also, it is used to be able to compare the process of mitosis between plant and animal cells.

Mitosis and meiosis are similar in several ways and different in others. The similarities include that both processes involve IPMAT. IPMAT is interphase, prophase, metaphase, anaphase and telophase. The parent cells are diploid. They both end with cytokinesis. In Metaphase and Metaphase II, the sister chromatids line up along the center. Then in Anaphase and Anaphase II, these chromatids are split and pulled towards the centrosomes. The differences are that mitosis consists of 1 division while meiosis consists of 2. Four genetically different, haploid sex cells are the products of meiosis and 2 identical, diploid somatic cells from mitosis. Mitosis occurs in all organisms except viruses and meiosis only occurs in plants, animals, and fungi.

“All types of cells undergo mitosis during formation of the embryo, but many adult cells, such as nerve cells, lens cells of the eye, and muscle cells, lost their ability to replicate and divide. The cells of other tissues, particularly epithelial cells [e.g., of the intestine, lung, skin), divide continuously and rapidly, competing the entire cell cycle in less than 10 hours” (McChance & Huether, pg. 35).

Although mitosis is just a fraction of time compared to interphase it can be divided into four distinct subphases. If we start viewing a cell under a brightfield microscope right at the end of interphase subphase G2 we would see that throughout the interphase process (fig 1) the cell has grown considerably in size due to production of extra mitochondria and endoplasmic reticulum. The cell has also gone through the labor of duplicating all of its chromosomes, a process known as DNA synthesis. Now that the cell has made all of these preparations it's time to start prophase (fig 2), the first stage of the mitotic phase. This stage is visibly identified by the chromatin becoming the tightly formed chromosomes. During the lab we were able to view these newly formed chromosomes best on the onion root tip

The cell cycle is a series of stages that occurs when a new cells makes the division from the parent cell to two daughter cells. This is a stage in cellular reproduction. The cell cycle consists of three phases, interphase, mitosis, and cytokinesis. During Interphase, a cell will continue to perform its functions as usual. The time frame for Interphase varies; while an embryonic cell will take just a few hours to complete the cycle, a stem cell from an adult can take 24 hours (Mader, Windelspecht, 2015). After the interphase stage completes itself, a complete nuclear division happens and mitosis occurs. During the stage of mitosis, the daughter cells will receive the same amounts of the contents of the parent cell. Throughout the last stage, in the cytoplasm there is a division known as Cytokinesis (Mader, Windelspecht, 2015). Cytokinesis occurs differently in plant cells than it does in animal cells, as the cell wall around the plant prevents the process from happening the same way. Instead, a new plasma membrane and cell walls are built are built between the daughter cells. However, in animal cells a single cell will become two (Mader, Windelspecht, 2015).

3. Switch to high power and center your slide in the apical meristem region, so that you have a field of view in which there is a wide selection of cells in various stages of mitosis (including interphase). Be sure to adjust your light for optimum viewing. Refer to Figure 3A, 3B, 3C: Stages of mitosis in onion root tip cells for guidance.

16) If the S phase were eliminated from the cell cycle, the daughter cells would

The cell cycle has four main stages. The cell cycle is the regular pattern of growth. The four stages consist of Gap 1 (G1), Synthesis (S), Gap 2 (G2), and Mitosis (M). Gap 1, consists of a cell that carries its normal functions. Calls also increase in size, and the organelles increase in number. A cell will spend the most time in this phase. But it also depends on the cell type to see how long it will spend in this phase. During this phase the cell has to pass a critical checkpoint before it can continue into the (S) stage, also called the Synthesis stage. It would be dangerous for a cell to keep dividing if the certain conditions were not met. The cells in this stage also need signals from the other cells to tell the if division is needed. Now the next stage is the Synthesis stage. During this phase the cell makes a copy of it’s nuclear DNA. By the end of the (S) phase DNA appears grainy in photos and the cell nucleus contains two complete sets of DNA. Gap 2, is the third stage of the cell cycle. The cells continue doing there thing and more growth occurs. This phase is like the checkpoint, everything in the cell has to be going right for the cell to be able to enter mitosis.

cell will look just like any other 'normal' cell although this is far from the

To observe mitosis in onion root tip cells and record the different phases of mitosis.

Plants are organisms that can reproduce sexually through meiosis and create more cells through mitosis (Russell et al. 2013). For studying mitosis, the common onion is an ideal choice. Because it is easy for onions to germinate without soil, it is easy to control any substances provided to the plant. The onion root tips are only a few cells thick and grow quickly making them ideal for time efficiency. The onion root tip needs to be squashed between the cover slip and the microscope in order to reduce the slide preparation’s total depth. To dye condensed chromosomes, such as those undergoing mitosis, a stain is used to make

Making the onion tip root cell slide was successful. Our results supported the hypothesis because we saw cells in the onion root tip in prophase, metaphase, and anaphase. As we went up in power objectives, each phase of the cell became more definitive. The cell root was a great indicator of the structures of the different cycles of the cell. This is important because we will be prepared for future labs working with the microscopes and can now adjust it for the best view of the slide. We practiced working with the compound light microscopes and different phases of the cell cycle. Onion root tips are useful to observe mitosis because the cells are frequently diving as the root grows. So when we stained the cell, we caught many cells in different phases. The significance of this lab was to better understand the process and stages of mitosis and meiosis and compare and contrast the mitotic process in plants and animals. We grasped the concepts of what the chromosomes look like, and what they look like in each step of the processes. Having read much about mitosis and meiosis, seeing these cells was the real application of describing and understanding the stages.