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Difference between mitosis and meiosis
Difference between mitosis and meiosis
Comparing and contrasting mitosis and meiosis
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More than one celled organisms grow by way of mitosis and the cytoplasmic division of body cells. On the other hand, meiosis occurs only in germ cells, which are put aside for the formation of gametes (sperm and egg). Reproduction by meiosis allows for species survival and it increases genetic variability.
The process, during which the germ cells are generated is called meiosis. It represents nature's solution to the problem of chromosome doubling that would occur, if two diploid cells, i.e. two cells with a double set of chromosomes would fuse. Accordingly does meiosis produce haploid germ cells, with maternal and paternal germ cell fusing at fertilization and thus generating a diploid fusion product, the zygote. Meiosis is made up by two subsequent processes, both of which resemble mitosis. In the first process are the homologous chromosomes separated. It has an unusually long prophase that is subdivided into different stages They are followed by metaphase, anaphase and telophase.
Two nuclei fuse upon fertilization, so that the number of chromosomes does necessarily double. If this thought is spun further, would an greater growth of the number of chromosomes from generation to generation have to be expected. This is not the case, because the chromosomes are reduced to half their normal number in germ cell production. This process is called meiosis. It consists of two successive mitosis-like divisions: in the first division is the number of chromosomes reduced to their half, the second is a normal mitosis.
Each germ cell contains a complete set of chromosomes, a haploid set. Accordingly are the cells haploid and zygotes and the body cells that stem from them are diploid, because they contain two equal sets of chromosomes, one from the mother and one from the father. They exist, especially in plants.
At the beginning of meiosis, in prophase 1 the plate breaksdown and chromosomes become visible as in mitosis (1). The chromosomes have replicated but individual chromatids are not visible. Instead of lining up on a metaphase, as in mitosis, chromosomes come together in pairs (2). Each chromosome in a pair is similar in structure (homologous), but would have come originally from different parents. Later in propha...
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...hese daughter chromosomes then begin to separate from each other, each moving away from the metaphase plate and toward one of the two spindle pole regions. The mechanisms that control chromosome separation clearly involve the interactions between microtubules and components in or near the kinetochore.
Sometime after anaphase onset, the chromosomes have moved close to the spindle pole regions, and the spindle middle begins to clear. In this middle region of the spindle, a thin line of vesicles begins to grow. The vesicle aggregation event is a harbinger to the assembly of a new cell wall that will be positioned midway along the length of the original cell. It will form the boundary between the newly separating daughter cells. This basket shaped structure forms in late anaphase or early telophase and breaksdown about the time that the vesicles begin to grow.
In Meiosis and Meitosis we deal with many of the same stages that it takes to create a new life form. Cell Division in meiosis and meitosis are very similar in that they can create and vary cell formation to adapt to certain applications,
“What light is to the eyes - what air is to the lungs - what love is to the heart, freedom is to the soul of man” (Brainy Quotes). Light is essential to the eyes, love is what makes the heart beat, and freedom is the hope of man kind; all of which are essential to the happiness of humanity. Having to live without these rights is a difficult way of living. For example, Cubans have suffered time after time in pursuit of their freedom, but sadly they never accomplish their goal. They live in fear of their broken government, but never stop fighting for freedom. In the early 20th century, Cuba was a democracy. From 1940 to 1944 Fulgencio Batista, a Cuban politician, was Cuba’s president. In 1952 he decided to run again, but when it was apparent he’d lose, Batista seized power before the election took place. The citizens were outraged causing them to turn against their flawed democracy that was brought upon by the election. As a result, Fidel Castro, a communist revolutionary political man, began to plot Batista’s downfall. The Cuban Revolution, also known as Castro’s Revolution, began on July 26, 1952, and ended January, 1, 1959. After Batista, Cuba’s former president, fled the country, Castro took complete control and turned Cuba into a communist country. The Revolution brought upon: many deaths, censored news and publicity, and no freedom of speech. Throughout the years Castro stayed in power, but due to health issues originating on July 31, 2006, he had to step down. After Castro returned, he took control of Cuba up until February 19, 2008. He then abdicated his place as dictator and handed down his position to his brother, Raul Castro.
these are egg cells and sperms, each with a reduced or halved number of. chromosomes. The chromosomes are. The number of chromosomes is restored when two gametes fuse together to form a zygote. A cell with two copies of each. chromosome is called a diploid cell and a cell with one copy of each.
The process of mitosis can take place in either a haploid (23 chromosomes) or a diploid (46 chromosomes) cell. Before a cell can be ready for a mitotic division it must primarily undergo its interphase stage. Following the interphase stage several other stages come into play. These stages are prophase, prometaphase, metaphase, anaphase, and telophase. During each specific stage certain sequences of events take place that assist to the completion of the division.
The article " Promissory estoppel" helped me understand promissory estoppel because in the article it talks about what promissory estoppel is and they also broke down promissory estoppel for a better understanding. The article states that the elements that a promissory estoppel needs to make a claim is "a promisor, a promisee, and a detriment that the promisee has suffered" (Investopedia,
Alexander Hamilton was born on January 11 in either 1755 or 1757. The exact date is unknown, since even he didn’t know the exact year. Born in the West Indies to Rachel Fawcett Lavien and James Hamilton, he was the product of an affair. His mother, Rachel
Cuba’s economy became stagnant, private businesses were confiscated, and due to fear of their leader and further collapse, the people fled for the United States in waves. As Charlip discussed, to keep the economy afloat, Castro had to open the country to foreign investment and introduce components of capitalism to the economy. These factors enabled Cuba’s economy to stabilize. It is interesting that when socialism failed, capitalism was the solution, particularly because Castro once said, “I find capitalism repugnant. It is filthy, it is gross, it is alienating... because it causes war, hypocrisy and competition.” His frustration with the fall of the Soviet Union and the humiliation he faced with the U.S. for turning to capitalism was
In the Prophase, chromosome as double threads joined at centromere and then shorten and thicken. Then nucleolus and nuclear membrane disappears. Fibrils of astral rays extend across forming mitotic spindle. After that centriole divides into two.
Mitosis is the type of cell division that produces somatic cells. This means that all body cells, such as skin cells, muscle cells, hair cells, etc are produced through mitosis. These cells are all diploid
You begin life as a single cell, formed when the sperm fertilises the egg. Out of all the sperm it only takes one sperm and one egg to fertilise at conception. This is called fertilization; which takes place in the Fallopian tube, the fertilized egg then divides
Born in the British West Indies, Alexander Hamilton was a bright and talented young man. In 1772, he moved to the mainland to attended King’s College in New York City. Soon after, he quickly embarked on an extraordinary career. Between his arrival in America and his death, Alexander Hamilton contributed greatly to establish our governmental framework. He fought under George Washington in the Revolutionary war and was a member of the Continental Congress. He was an advocate for the ratification of the Constitution and established a prestigious law career. He then served as the nation’s first Secretary of the Treasury. Hamilton was always one step ahead, his leadership skills and intelligence demonstrated to be valuable in his political path.
Originally a dictator ran Cuba: President Fulgencio Batista, who was an ally to the United States. Cuba during this time enjoyed a healthy urban middle class, and its citizens enjoyed some degree of freedom without a police state. Many other countries seemed a lot more likely to revolt, because economically and developmentally, Cuba seemed stable. However, the United States’ role and control of Cuba’s economy started to take its toll on the “peasants”. In 1953, the United States owned many of the major entities, such as 50% of the railroad. Just as much development as there was in the urban areas there was a lack thereof in the rural areas. Not just economically, Cubans started to resent the image of Sin City that Americans gave the country. Cuba was a popular tourist spot where Americans came to behave badly. Castro’s success came from these opposite sides of distaste for the United States, the peasants economically and the middle class socially & nationally. Castro was not originally a socialist; he was a nationalist first. However when he attacks Moncada Barracks, he is arrested and exiled to Mexico City. During this time his failures are turned into “successes” through propaganda. Castro meets with Che Guevara in Mexico City and when he returns, he purges the military of 483 Batista loyalists and enacts land reforms and nationalizes US
The first sub phase of this is prophase 1 and this is split up into 5 stages. The first one is leptotene and this is where the chromosomes supercoil. The second one is zygotene and this is where the homologous chromosomes form pairs and these are called bivalents. Pachytene is where crossing over occurs between the homologous chromosomes and chiasmata form. Diplotene is where they start to separate but remain attached to each other by the chiasmata. Diakinesis is the last stage and this is where they keep separating and the chiasmata moves to the ends of the chromosome (GENIE, 2010). The second phase is prometaphase and this is where the spindle fibres assemble and the chromosomes become anchored to them by their kinetochores. Metaphase 1 is where the bivalents assort randomly on the metaphase plate. This helps to create genetic diversity. Anaphase 1 is where the bivalents separate and the homologous chromosomes move to opposite poles of the cell. Telophase 1 is where the nuclear envelope reforms after disintegrating in prophase 1. Then cytokinesis is where the cell divides to create two new cells which are haploid (GENIE, 2010). The next main stage is meiosis 2 and this is where each chromosome is split into 2 sister chromatids. Prophase 2 is the first stage and this is where the chromosomes supercoil, the mitotic spindle forms and the nuclear envelope disintegrates. Metaphase 2 is where the chromosomes become attached to the
Alexander Hamilton was disliked by many people, nevertheless, he is now popular because of a hit Broadway show created by Lin-Manuel Miranda. Born on January 11, 1755 or 1757 in Charleston, Nevis in the British West Indies and abandoned by his father at thirteen, Hamilton’s determination made him successful in business and politics. First he attended school in Elizabethtown, New Jersey but, plans changed, and he entered Kings College. At the age of seventeen he was already interested in government. Later, in 1776 he was introduced to George Washington. He became Washington’s trusted advisor not long after they were introduced. Some main events that shaped Hamilton’s life were his family, his accomplishments, and George Washington.
One chromosome has been donated from each parent cell in order to create a homologous chromosome pair. These chromosomes have identical lengths and gene placement but can contain different alleles. When homologous chromosomes attach at the centromere they create a tetrad, which is defined as a pair of sister chromatids. Once the sister chromatids are attached, the non-sister chromatids participate in crossing over. Crossing over is the transfer of genetic information in order to create greater genetic variability. In metaphase I, the centromere of each tetrad attaches to spindle fibers. These spindle fibers slowly shift the tetrads position to the center of the cell until they are side by side. Immediately after they line up, homologous chromosomes are separated by microtubules called kinetochore fibers that are used to pull sister chromatids to opposite poles of the cell. Once the sister chromatids are on opposite poles of the cell, anaphase I is complete and the cytoplasm of the cell begins to separate. This is known as cytokinesis and occurs during telophase. Once meiosis I is complete, meiosis II begins and repeats each step, however, instead of two haploid cells there will be a total of
For the cell, the job of meiosis is the reduction of number of chromosomes of the gametes from diploid to haploid. The job of meiosis in the chromosome is to go through both of the phases and produce more new cells to have the four haploid daughter cells. Finally, the job of meiosis in the organism is to reproduce sexually by making sex cells in humans, animals, plants, and fungi.