Types Of Cell Division First Go Through Interphase Essay

Meiosis consists of one DNA replication and two nuclear divisions resulting in 4 daughter cells. The process which provides for genetic variation is crossing over. Crossing over occurs in the early stages when homologous chromosomes move together so that their chromatids form a tetrad. This is called synapsis and allows for the exchange of chromosome sections.

Interphase: This particular stage is divided into three phases, G1 (first gap), S (synthesis), and G2 (second gap). During all three phases, the cell grows by producing proteins and other organelles within the cytoplasm. However, chromosomes are replicated only during the S phase. In all, a cell grows (G1), continues to grow as it duplicates its

These bivalents line up along the equator during metaphase I, the arrangement of the bivalent is completely random and relative to the orientation of the other bivalents, this is known as the independent assortment of chromosomes. This is followed by anaphase I where the homologous chromosomes separate and move to the opposite poles of the cell. At telophase I the cell divides into two, each cell contains one chromosome from each homologous pair. The second stage of meiosis is similar to mitosis.

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.

A) Meiosis consists of two cell divisions and is broken up into Meiosis I and Meiosis II. At the beginning of the Cell Cycle, in this case there are four chromatids each from the homologous pairs being A, a, B, b. This is the Diploid number (4) meaning it is 2 times the haploid number that will be seen at the end of meiosis II. During the S phase of interphase, the chromatids replicate and reach the end of G2 phase. Now starting meiosis, during the first stage of prophase I the chromosomes condense and pair up through synapsis with their sister chromatids creating AA, aa, BB, bb. After they pair up they go through a process called crossing over, where the homologous chromosomes share a piece of their genetic material with each other. Crossing over allows for the genetic diversity of chromosomes. Now there are four homologous chromosomes Aa, Aa, Bb, Bb, each containing heterozygous alleles because the sister chromatids exchanged genetic information with their homologous pair. During late prophase I, spindle fibers being to form where they will later attach to a homologous chromosomes centromere. The next stage is Metaphase I. During metaphase I, the homologous pairs line up at the metaphase plate, also known to be the center of the cell. The homologous pairs form a tetrad which is considered a group of four homologous chromosomes. These homologous chromosomes orient themselves randomly, which is know as the process of independent

2. In which phases of mitosis are sister chromatids visible, and attached to each other at the centromere?

Without cell division and the cell cycle nearly all life would fail to exist. Cell division allows an organism to not only replace its own cells but to create offspring. The cell cycle consists of two main parts: interphase and mitotic phase. Within these two phases the processes can be broken down into further categories. Interphase can be broken down into three subphases that are the necessary preparations the cell makes in order to be ready to divide during mitosis. For this lab we looked mainly at the mitotic phase because of its fascinating and rapid changes to the cell. The cell types we looked at were prepared slides of whitefish and onion root tip.

The phase in mitosis which chromatin begins to coil and the mitotic spindle begins to form.

[A labelled diagram of Metaphase here, and put a note next to it saying "Note

Mitosis is one of two main methods of cell replication, the other being meiosis. It is “the simple duplication of a cell and all of its parts” resulting from the splitting of a cell. The ‘parent’ or original cell splits, duplicating its DNA (packaged in chromosomes) producing two ‘daughter’ or new cells with the same genetic code. There are four stages of mitosis; Prophase, Metaphase, Anaphase and Telophase. Interphase is not an official phase of mitosis as the cell is at ‘rest’ and not being divided during this phase. It is often called one of the phases of mitosis as it is one of the stages in the life cycle of a cell; however it is not a phase of mitosis due to the fact that no division takes place.

Response Feedback: Meiosis occurs only in replicating gametes or reproducing cells. In phase one, the number of chromosomes is reduced by half but the chromatid pairs remain together. In phase two, the chromatids split apart forming four daughter cells. Non-germ cells such as red blood cells or skin cells undergo mitosis.For more information on this topic, consult:Carol Mattson Porth and Glen Matfin, Pathophysiology, 8th Edition,

A new cell starts after the division and production of two new cells. Each new cell undergoes metabolism, growth and development. At the end of its cycle the cell divides and produces two new cells which then undergo further cell cycle. (Elseth .G et al)

The results of this lab showed the stages and events that occur in meiosis and mitosis. The four stages of mitosis were observed in the blastula staged whitefish embryo slides. The phases of mitosis are prophase, metaphase, anaphase, and telophase. The beginning stages that occur in mitosis take place in interphase, which are G_1, S, and G_2. In the G_1 stage, the cell begins to increase in size. After the size of the cell has increased it proceeds to the S stage where the chromosomes start to replicate themselves and attach together to the centromere. When the chromosomes are finished replicating themselves, it enters the G_2 stage where proteins check the integrity of the DNA. If everything is normal, the chromosomes are allowed to enter mitosis and begin the cell division process.

Next comes the third phase of mitosis, Anaphase, in which the centromeres break in half, causing each of the daughter chromatids to start to be pulled to different poles of the cell by means of spindle fibers. The spindle fibers pull the daughter chromatids until they reach the poles of the cell. Finally, the last phase of mitosis called Telophase in which the daughter chromatids are fully pulled toward the poles and the nuclear envelope begins to reappear, the cell also begins to cleave, usually in the spot where the chromatids lined up in metaphase. After mitosis is complete, cytokinesis occurs, cytokinesis is the process in which a cell’s cytoplasm is split into two equal parts, therefore causing the mother cell to split into two daughter cells.

The main focus of this lab was to be able to understand the different phases of mitosis and the cell cycle and also identify what those stages may look like. Mitosis is the process in which concerns the production of new cells. For example, when apoptosis(cell death) the process of Mitosis begins to replace the dead cells. To be able to familiarize ourselves with this concept, we took a sample of an onion root and had it put through a process to be able to look at the different phases under the microscope. We found that the majority of the cells were mostly undergoing Interphase or Prophase which are the phases in charge of crossing over of DNA and where the chromosomes then become visible and the nuclear envelope dissipates. The conclusion of this lab was that Mitosis is essential for the production of new cells. In the case of the onion root sample, the cells were damaged leading to the tester to undergo Mitotic cell division and it was found that mainly Interphase and Prophase were the stages that occurred in this lab.