This is then followed by multistage structured processes that result into daughter cells, mitosis and meiosis essay, depending on the genetic composition of the mother cell. Having trouble finding the perfect essay? Get essay help. Cohesin forms rings that hold together the sister chromatids, whereas condensin forms ring that coil the chromosomes into highly compact forms. Both mitosis and meiosis represent cell division where the chromosomal constituents of cells are replicated.
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Home — Essay Samples — Science — Cell — The Process of Mitosis and Meiosis. Any subject. Any type of essay. Meiosis is a process where a single cell divides twice to produce four cells containing half the original amount of genetic information. These cells are our sex cells — sperm in males, eggs in females. During the process of meiosis one cell divides two times to form four daughter cells. These four daughter cells only have half the number of chromosomes of the parent cell which are called haploids. Meiosis produces our sex cells or gametes which are eggs in females and sperm in males. Meiosis can be divided into nine stages. These are divided between mitosis and meiosis essay first time the cell divides meiosis I and the second time it divides meiosis II : Meiosis I.
Mitosis: Mitosis is the process where a eukaryotic cell nucleus separates in two, followed by division of the parent cell into two daughter cells. These tubules, collectively known as the spindle, expand from structures called centrosomes, with one centrosome located at each of the opposite ends, or poles, of a cell. As mitosis starts progressing, the microtubules join to the chromosomes, which mitosis and meiosis essay already duplicate their DNA and have come together across the center of the cell. The spindle tubules then contract and move toward the poles of the cell. As mitosis and meiosis essay move, they pull the one copy of each chromosome with them to opposite poles of the cell. This process ensures that each daughter cell will contain one exact copy of the parent mitosis and meiosis essay DNA.
What Are the Phases of Mitosis? Mitosis is composed of five morphologically distinct phases: prophase, mitosis and meiosis essay, prometaphase, metaphase, anaphase, and telophase. Each one of these phases involves characteristic steps in the process of chromosome alignment and separation. Once mitosis is complete, the entire cell divides in two by way of the process called cytokinesisProphase which is the first stage in mitosis, occurring after the conclusion of the G2 portion of interphase. During prophase, the parent cell chromosomes, which were duplicated during S phase — condense and become thousands of times more compact than they were during interphase, mitosis and meiosis essay.
Due to the fact that each duplicated chromosome consists of two identical sister chromatids joined at mitosis and meiosis essay point called the centromere, these structures now appear as X-shaped bodies when viewed under a microscope. Several DNA binding proteins catalyze the condensation process, including cohesin and condensin. Cohesin forms rings that hold together the sister chromatids, whereas condensin forms ring that coil the chromosomes into highly compact forms. Also, the mitotic spindle begins to develop during prophase. What Happens during Prometaphase? After prophase is complete, the cell enters prometaphase which is the second stage of mitosis. During prometaphase, phosphorylation of nuclear lamins by M-CDK causes the nuclear membrane to break down into numerous small vesicles.
Therefore, the spindle microtubules now have direct access to the genetic material of the cell. Each microtubule is highly dynamic, growing outward from the centrosome and falling down backward as it tries to locate a chromosome. Ultimately, the microtubules find their targets and connect to each chromosome at its kinetochore, a complex of proteins positioned at the centromere. The actual number of microtubules that link to a kinetochore varies between species, but at least one microtubule from each pole link to the kinetochore of each chromosome. A tug-of-war then ensues as the chromosomes move back and forth between the two poles. What Happens during Metaphase and Anaphase?
As mitosis and meiosis essay ends and metaphase begins, the chromosomes adjust along the cell equator. Every chromosome has at least two microtubules extending from its kinetochore and with at least one microtubule connected to each pole. At this point, the tension within the cell becomes balanced, and the chromosomes will no longer move back and forth, mitosis and meiosis essay. In addition, the spindle is now complete, and three groups of spindle microtubules are apparent. Kinetochore microtubules connect the chromosomes to the spindle pole; interpolar microtubules develop from the spindle pole across the equator, almost to the opposite spindle pole; and astral microtubules develop from the spindle pole to the cell membrane.
Metaphase then leads to anaphase, during which each chromosome sister chromatids separate and move to opposite poles of the cell. Enzymatic breakdown of cohesin — which linked the sister chromatids together during prophase — causes this separation to occur. Upon separation, every chromatid becomes an independent chromosome. Changes in microtubule length provide the mechanism for chromosome movement. More specifically, in the first part of anaphase — sometimes called anaphase A — the kinetochore microtubules shorten and draw the chromosomes against the spindle poles. Then, in the second part of anaphase — at times called anaphase B — the mitosis and meiosis essay microtubules that are anchored to the cell membrane pull the poles further apart and the interpolar microtubules slide past each other, exerting an additional pull on the chromosomes.
During telophase process, the chromosomes arrive at the cell poles, the mitotic spindle disassembles, and the vesicles that include fragments of the original nuclear membrane assemble around the two sets of chromosomes. Phosphatases then dephosphorylate the lamins at every end of the cell. This dephosphorylation results in the development of a new nuclear membrane mitosis and meiosis essay each group of chromosomes. When Do Cells Actually Divide? Cytokinesis is the physical process that finally splits the parent cell into two identical daughter cells. During this process, the cell membrane pinches in at the cell mitosis and meiosis essay, forming a cleft called the cleavage furrow.
The position of the furrow will depend on the position of the astral and interpolar microtubules during anaphase. The cleavage furrow then forms because of the action of a contractile ring of overlapping actin and myosin filaments. As the actin and myosin filaments move passing each other, the contractile ring becomes smaller, akin to pulling a drawstring at the top of a purse. When the ring reaches its smallest point, the cleavage furrow completely bisects the cell at its center, resulting in two separate daughter cells of the same size. Remember: This is just a sample from a fellow student. Starting from 3 mitosis and meiosis essay delivery. Sorry, copying is not allowed on our website, mitosis and meiosis essay. We will occasionally send you account related emails.
This essay is not unique. Sorry, we could not paraphrase this essay. Our professional writers can rewrite it and get you a unique paper, mitosis and meiosis essay. Want us to write one just for you? We use cookies to personalyze your web-site experience. This essay has been submitted by a student. This is not an example of the work written by professional essay writers. The Process of Mitosis and Meiosis Subject: Science Category: Biology Topic: Cell Pages 4 Words: Published: 17 December Downloads: 33 Download Print. Get help with writing. Pssst… we can write an mitosis and meiosis essay essay just for you. Your time is important. Get essay help. Related Essays Sickle Cell Disease Essay. Phases of Glycolysis Essay. Cell signalling and G-Protein Essay.
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Any subject. Any type of essay. Mitosis and meiosis are both forms of cell division, however, their processes are not identical. Mitosis happens in somatic cells cells that are not gametes , and it produces two genetically identical daughter cells. Mitosis happens to replace dead or damaged cells or during growth. Mitosis consists of 4 phases: prophase, metaphase, anaphase, and telophase. DNA replication happens during S phase which is before the mitotic phase. During prophase, the chromatin condense into chromosomes, and the mitotic spindle forms textbook, During metaphase, the chromosomes line up along the middle of the cell, known as the metaphase plate.
During anaphase, the chromatid pairs separate, and each half of the pair is called a chromosome. During telophase, the last stage of mitosis, the identical sets of chromosomes are at opposite poles of the cell, the chromosomes revert back to chromatin, and a nuclear envelope reforms around each group of chromatin. The division of the cytoplasm after nuclear division is called cytokinesis textbook, Meiosis, in contrast, occurs in gametes sex cells , produces four genetically different daughter cells, and involves two divisions of genetic material. Meiosis is broken up into into two parts: meiosis I and meiosis II which both consist of four parts.
Meiosis I occurs first after DNA replication and consists of prophase I, metaphase I, anaphase I, and telophase I. Prophase I, much like prophase in mitosis, is when the chromosomes shorten and the mitotic spindle forms. However, unlike prophase in mitosis, the two genetically identical sister chromatids pair off, and crossing over occurs between non sister chromatids. Crossing over is the very important reason that no two people have the same DNA. Metaphase I is very similar to metaphase in mitosis because the homologous pairs of chromosomes line up along the metaphase plate. In anaphase I, the homologous pairs of chromosomes are separated and pulled to opposite sides of the cell leaving the paired chromatids still together textbook, Meiosis I results in two genetically different haploid cells after telophase I and cytokinesis which are similar to telophase and cytokinesis of mitosis.
Meiosis II consists of prophase II, metaphase II, anaphase II, and telophase II. Prophase II is similar to prophase in mitosis, and no crossing over occurs during prophase II. Oliferenko, S. Positioning cytokinesis. Schellhaus, A. Nuclear reformation at the end of mitosis. Journal of Molecular Biology, 10 , — Need help with your essay? Feel free to buy your own Essay with our essay writers — Handmadewriting. Linguistics is an English language category that deals with logical dialectal analysis and interpretation. It seeks to reveal the form, meaning, and context of language. While most college students may perceive linguistics as a simple subject, it is pretty complex.
English tutors might issue topics in linguistics in various disciplines like phonology or semantics, which leaves many learners grappling to tackle the research papers. Astronomy is the study of the universe and the physical entities surrounding it. These celestial objects include the moon, sun, stars, planets, comets, and meteorites. It incorporates several subject disciplines that allow students to understand the concept of the course. That is why it provides an extensive foundation for research papers in colleges and universities. Astronomy is an exciting subject with broad, complex topics. Since the subject concentrates on the universe and space, most students find the themes unfamiliar and confusing.
Food is a sensitive topic since it impacts human lives directly. As experts say, you are what you eat is indeed true that the meals you consume can either build or weaken your immune system. Careful diet selection affects your health immensely. You need to eat nutritious meals to maintain a healthy lifestyle and lower the risks of various diseases. That is why there are numerous diet courses and programs offered in colleges and universities. Articles Bloggers Guides Samples. Samples 23 March, 7 minutes read Author: Kate Smith. This Essay sample was written by Handmadewriting Team The continuation of generations and the growth thereof of organism utilizes the process of cell division, especially in eukaryotic cells where this process takes the form of either mitosis or meiosis.
These are divided between the first time the cell divides meiosis I and the second time it divides meiosis II : Meiosis I. Mitosis: Mitosis is the process where a eukaryotic cell nucleus separates in two, followed by division of the parent cell into two daughter cells. These tubules, collectively known as the spindle, expand from structures called centrosomes, with one centrosome located at each of the opposite ends, or poles, of a cell. As mitosis starts progressing, the microtubules join to the chromosomes, which have already duplicate their DNA and have come together across the center of the cell.
The spindle tubules then contract and move toward the poles of the cell. As they move, they pull the one copy of each chromosome with them to opposite poles of the cell. This process ensures that each daughter cell will contain one exact copy of the parent cell DNA. What Are the Phases of Mitosis? Mitosis is composed of five morphologically distinct phases: prophase, prometaphase, metaphase, anaphase, and telophase. Each one of these phases involves characteristic steps in the process of chromosome alignment and separation. Once mitosis is complete, the entire cell divides in two by way of the process called cytokinesisProphase which is the first stage in mitosis, occurring after the conclusion of the G2 portion of interphase.
During prophase, the parent cell chromosomes, which were duplicated during S phase — condense and become thousands of times more compact than they were during interphase. Due to the fact that each duplicated chromosome consists of two identical sister chromatids joined at a point called the centromere, these structures now appear as X-shaped bodies when viewed under a microscope. Several DNA binding proteins catalyze the condensation process, including cohesin and condensin. Cohesin forms rings that hold together the sister chromatids, whereas condensin forms ring that coil the chromosomes into highly compact forms.
Also, the mitotic spindle begins to develop during prophase. What Happens during Prometaphase? After prophase is complete, the cell enters prometaphase which is the second stage of mitosis. During prometaphase, phosphorylation of nuclear lamins by M-CDK causes the nuclear membrane to break down into numerous small vesicles. Therefore, the spindle microtubules now have direct access to the genetic material of the cell. Each microtubule is highly dynamic, growing outward from the centrosome and falling down backward as it tries to locate a chromosome. Ultimately, the microtubules find their targets and connect to each chromosome at its kinetochore, a complex of proteins positioned at the centromere.
The actual number of microtubules that link to a kinetochore varies between species, but at least one microtubule from each pole link to the kinetochore of each chromosome. A tug-of-war then ensues as the chromosomes move back and forth between the two poles. What Happens during Metaphase and Anaphase? As prometaphase ends and metaphase begins, the chromosomes adjust along the cell equator. Every chromosome has at least two microtubules extending from its kinetochore and with at least one microtubule connected to each pole. At this point, the tension within the cell becomes balanced, and the chromosomes will no longer move back and forth.
In addition, the spindle is now complete, and three groups of spindle microtubules are apparent. Kinetochore microtubules connect the chromosomes to the spindle pole; interpolar microtubules develop from the spindle pole across the equator, almost to the opposite spindle pole; and astral microtubules develop from the spindle pole to the cell membrane. Metaphase then leads to anaphase, during which each chromosome sister chromatids separate and move to opposite poles of the cell. Enzymatic breakdown of cohesin — which linked the sister chromatids together during prophase — causes this separation to occur.
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