role of mitosis in the production of gametes?
954953
Mitosis plays a role in the production of the population of cells that will give rise to the gametes, but not in the production of the gametes themselves. Sperm and ova are produced beginning with 'meiosis' or "reduction division". The immediate precursor cell to these gametes undergoes cell division with the separation of the diploid chromosome number to yield cells that are haploid, they only carry one of each chromosome and not the pair that is produced during mitosis in all other somatic cells.
860073
D is the answer.  One cell differentiates and the other cell remains pleuripotent (has the ability to differentiate into many other types of cells).\nHere is why the other choices are incorrect.  Sometimes the other cell will die.  This happens in certain types of ground tissue, but only after the cell has differentiated into a specialized type of cell, which is why A is not the answer.  B is not the answer because gamete in plants is only formed by mitosis.  Only the gametophyte produces gametes and gametophytes are haploid so they only need to undergo mitosis to produce a gamete.  C is not the answer becuase the formation of a zygote requires the fusion of two cells, which does not happen under hte conditions of this question.
858390
Firstly you should ask the proper ques. The ques. should be like this "What is the difference b/w meosis and mitosis".\n        The answer to your ques. is:-\n       MITOSIS                                       MEOSIS\n* Takes place in somatic                  * Takes place in reproductive\n   cells                                                   cells                                    \n* Produces two cells                         * Produces four haploid cells\n* No crossing over                             * Crossing Over takes place\n*The no. of chromosomes re-           * The no. of chromosomes \n  mains the same after mitosis             is reduced to one-half after\n                                                              meiosis
740160
1- Meiosis happens in stem cells that give rise to gametes (sex cells). \nMitosis happens in all other cells.\nIn women every month only one stem cell goes through meiosis forming 4 haploid cells. In men many cells go through meiosis everyday.\nEvery other cell in body goes through mitosis in a daily basis to replace old and dead cell.\n2- Before cell replication starts.\n3- At the end of the prophase (in case of meiosis, end of the prophase 1)\n4- Mitosis: diploid cells; Meiosis: haploid cells\n5- Every thing but cell division: the cell obtain nutrients and when it gets close to cell division, it will duplicate its DNA and other organelles.
888340
When cells undergo meiosis, sometimes the cells divide incorrectly and either, gametes that have abnormal number of chromosomes are formed, or the cell ends up with multiple copies of the genome. Cells that have many sets of chromosomes are said to be undergoing polyploidy. The genetic material has been duplicated and ready for division, but division does not occur, forming a gamete with an extra set of chromosomes.
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During s-phase of interphase, the genetic material is duplicated.    So #1 is FALSE.\n\nTelophase sees the production of the nulear membrane.  So in effect, new nuclei are formed, making #2 TRUE.\n\nMitosis creates two daughter cells that are diploid, because it is reproduction of somatic (body cells), no production of gametes (which would be haploid).  So, #3 is TRUE\n\nChromosome find their homolougous pair during prophase of Meiosis, NOT mitosis.  Pairing occurs during meiosis so the the gametes that are haploid can be formed. So #4 is TRUE\n\nEach species has a specific number of chromosomes- fruit flies for example have 8 chromosomes, while humans have 46.  So #5 is TRUE.
71089
Angiosperm Life Cycle\nI. Plant Life Cycles\n\nA. All of us are probably most familiar with the human life cycle. We know that, as adults, most of our cells have two sets of chromosomes, one from our mother and the other from our father. These cells (really the chromosome complement of their nuclei) are called diploid (2N). Special cells undergo meiosis where the chromosome number of the resulting cells are half that of the parent cell. These cells are haploid (1N) and develop directly into gametes (sperm and egg). These gametes fuse during fertilization to produce a zygote which divides through mitosis to form the adult organism. Bear in mind, the two important events in any life cycle (animal or plant) are fertilization and meiosis.\n\nB. In plants, things are a bit different because the products of meiosis (spores) don't immediately become gametes. They divide mitotically to form a completely separate organism! This organism is called the gametophyte and is haploid. The gametophyte may be composed of many cells and be a fully functional plant (such as the green leafy moss) or be composed of only a few cells (as in flowering plants).\n\nC. So how are the gametes formed? The gametophyte produces special structures that make the gametes via mitosis. After fertilization occurs, a diploid zygote forms and grows via mitosis to form the sporophyte which is diploid. This life cycle is called alternation of generations {0256}{0257}{0517}, because the gametophytic and sporophytic stages alternate with each other.\n\nII. Angiosperm Life Cycle {1075}\n\nA. Production of the male gametophyte {0258}. Each anther contains from one to four microsporangia. A microsporangium contains microspore mother cells (microsporocytes) that undergo meiosis producing haploid microspores {0291}{0294}{0295}. Each of the four components of the tetrad {0296} differentiate into pollen grains {0289}. Mitotic divisions result in a mature microgametophyte, otherwise known as pollen. Each pollen grain contains a tube nucleus and a generative nucleus {0290}. When the pollen grain lands on the stigma (below), the generative nucleus divides to form two sperm nuclei. {1086}\n\nB. Production of the female gametophyte {0259}. Inside the ovary are the ovules {0511} that eventually become seeds. The megaspore and later the megagametophyte form inside the ovule. The megagametophyte eventually produces the egg, the female gamete.\n\nInside a young ovule, one cell differentiates into a megaspore mother cell (megasporocyte) {0562}. Meiosis produces four megaspores, but usually only one of these survives. It divides mitotically three times {0563}{0565} giving eight nuclei (in seven cells) {0568}. One cell at the micropyle end of the ovule becomes the egg and the two nuclei in the large central cell function as polar nuclei.\n\nC. Pollination {0260}{0518}{1086}. If the pollen grain is on a compatible stigma, it attaches, germinates and forms a pollen tube which grows through the style tissue on its way to the ovule.\n\nD. Fertilization. When the pollen tube reaches the micropyle opening, it releases two sperm nuclei. One fuses with the egg forming a zygote {0261}, the other fuses with the already fused polar nuclei making a triploid fusion nucleus. This DOUBLE FERTILIZATION is a feature found only in angiosperms. The triploid fusion nucleus divides mitotically to form endosperm which is used as a nutritive tissue for the growing embryo {0615}.\n\nD. Fruits and seeds {0538}. The mature ovule becomes the seed. The integuments become the seed coat that surrounds the endosperm and embryo. The mature carpel (and sometimes associated tissues) becomes the fruit.
364043
There are actually TWO organelles that play a direct role in the process of cell division.\n\nThe centrioles are the structures that establish the poles during mitosis and meiosis. But don't forget the cytoskeleton, which is hugely important during the cytokinesis part of each process.
504487
The purpose of meiosis is to form haploid germ cells.  These cells only contain half the normal number of chromosomes, which is necessary during the fertilization process.  Each parent contributes half the normal number of chromosomes, thereby creating unique DNA within the offspring.  I hope this helps.
121913
the result of mitosis is 2 daughter cells which are exactly like the mother cell and that is how regular cells in the body reproduce, but in meiosis you get 4 gaughter cells that each have half the genetic material of the mother cell, in fact meiosis is like a mitosis in the begining but the cell divide once more without doubling the DNA. the cells in the reproductive glands divide like this and make the sperm and the ovuum.
746150
http://en.wikipedia.org/wiki/Mitosis\nhttp://en.wikipedia.org/wiki/Meiosis\n\nBecause meiosis is a "one-way" process, it cannot be said to engage in a cell cycle as mitosis does. However, the preparatory steps that lead up to meiosis are identical in pattern and name to the interphase of the mitotic cell cycle.
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remember the phases in meiosis (in order) :Prophase, Metaphase, anaphase, telephase (pmat)\nMitosis\nI  INTRODUCTION \n\nMitosis, process in which a cell’s nucleus replicates and divides in preparation for division of the cell. Mitosis results in two cells that are genetically identical, a necessary condition for the normal functioning of virtually all cells. Mitosis is vital for growth; for repair and replacement of damaged or worn out cells; and for asexual reproduction, or reproduction without eggs and sperm.\n\nAll multicellular animals, plants, fungi, and protists, which begin life as single cells, carry out mitosis to develop into complex organisms containing billions of cells. Mitosis continues in full-grown organisms as a means of maintaining the organism—replacing dying skin cells, for example, or repairing damaged muscle cells. In the cells of the adult human body, mitosis occurs about 25 million times per second. Multicellular organisms such as sea stars, sea anemones, fungi, and certain plants rely on mitosis for asexual reproduction at particular stages in their life cycles, and mitosis is the sole mode of reproduction for many single-celled organisms.\n\nII  INTERPHASE \n\nThe life cycle of eukaryotic cells, or cells containing a nucleus, is a continuous process typically divided into three phases for ease of understanding: interphase, mitosis, and cytokinesis. Interphase includes three stages, referred to as G1, S and G2. In G1, a newly formed cell synthesizes materials needed for cell growth. In the S stage, deoxyribonucleic acid (DNA), the genetic material of the cell, is replicated. At this stage, DNA consists of long, thin strands called chromatin. As each strand is replicated, it is linked to its duplicate by a structure known as a centromere. When the S stage is complete, the cell enters a brief stage known as G2, when specialized enzymes correct any errors in the newly synthesized DNA, and proteins involved with the next phase, mitosis, are synthesized. \n\nIII  MITOSIS \n\nMitosis occurs in four steps. In prophase the replicated, linked DNA strands slowly wrap around proteins that in turn coil and condense into two short, thick, rodlike structures called chromatids, attached by the centromere. Two structures called centrioles, both located on one side of the nucleus, separate and move toward opposite poles of the cell. As the centrioles move apart, they begin to radiate thin, hollow, proteins called microtubules. The microtubules arrange themselves in the shape of a football, or spindle, that spans the cell, with the widest part at the center of the cell and the narrower ends at opposite poles. As the spindle forms, the nuclear membrane breaks down into tiny sacs or vesicles that are dispersed in the cytoplasm. Final disintegration of the membrane marks the beginning of metaphase. \n\nIn metaphase, the spindle fibers attach to the chromatids near the centromeres, and tug and push the chromatids so that they line up in the equatorial plane of the cell halfway between the poles. Like two individuals standing back to back at the equator, one chromatid faces one pole of the cell, and its linked partner faces the opposite pole. This precise orientation is necessary in order for the next step, anaphase, to occur. Anaphase begins when the centromeres split, separating the identical chromatids into single chromosomes, which then move along the spindle fibers to opposite poles of the cell. \n\nAs these two identical groups of single chromosomes gather at opposite poles of the cell, telophase begins. A new nuclear membrane forms around each new group of chromosomes. The spindle fibers break down and the newly formed chromosomes begin to unwind. If viewed under a light microscope, the chromosomes appear to fade away. They exist, however, in the form of chromatin, the extended, thin strands of DNA too fine to be seen except with electron microscopes. Mitosis accomplishes replication and division of the nucleus,
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Check out "mitosis" in a suitable source (Wikipedia, for example).  The process is a bit long to describe here.
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Mitosis produces daughter cells genetically identical to the parent cell.\nThis has to be true since mitosis is the cell division producing growth - we would not expect entirely different bits and pieces to appear as we grew!\n\nThe first stage of mitosis is DNA replication. The following stages share out the exact copies of DNA equally between the daughter cells.
916206
Mitosis is a continuous process by which the body grows and dead body cells are replaced, in this type of cell division each "daughter cell " contains  the exact number of chromosomes as the "parent cell" 46 also called the diploid number. The process of mitosis  in sperm is called spermatogenesis  and in the ovum , called oogenesis.\nMeiosis is a different type of cell division where reproductive cells undergo 2 sequential divisions. During meiosis the number of chromosomes is reduced to half, 23 chromosomes also called the haploid number. At the moment of fertilization (when the sperm and ovum unite) the new cell contains 23 chromosomes from the sperm and 23 chromosomes from the ova returning to the diploid number of 46 and both the mothers and fathers traits are inherited by the gamete
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by the name of allah\ni'm an arabian from egypt\nstudient at the last year faculty of science alazhar university\nthe spermatogenesis is the process to produce the sperm \nit started in the testis \nSpermatogenesis begins at puberty and involves mitotic proliferation, meiotic division and extensive cell modeling It starts with the spermatogonia or germinal cells dividing mitotically to produce a small clone of diploid  cells termed spermatocytes. The spermatocytes migrate through the tight junctions at the base of the Sertoli cells and, in their new environment cradled by the Sertoli cells, undergo two meiotic divisions. In the first division, pairs of chromosomes come together and exchange DNA (crossing over) and separate into two haploid cells (23X or 23Y) known as secondary spermatocytes. Almost immediately, a second meiotic division takes place in which the two chromatids that make up a single chromosome separate. These haploid cells, thus, contain 23 single half chromosomes and are called spermatids.\n\nAt this stage, they are still simple round cells but before they leave the nurturing of the Sertoli cells an acrosome (essential for fertilization) is formed at the head of the sperm and a tail develops. They are extruded from the Sertoli cells into the lumen of the seminiferous tubule. This whole process of spermatogenesis takes approximately 74 days and about 300600 sperm/gram of testis are produced each second. Not all survive.\n\nFrom the seminiferous tubules, the sperm are washed towards the rete testis which drains into the vasa efferentia and from there into the epididymis, a highly convoluted tube that finally drains into the vas deferens During the 12 day passage from the testis to the vas deferens, the sperm become motile and mature to reach full fertilizing ability. As a result of fluid absorption in the epididymis, sperm also become highly concentrated.\n\nWhilst spermatogenesis is dependent on the hormonal drive from the gonadotrophins and testosterone, temperature also plays a critical factor in this process. Normal spermatogenesis is impaired if the testis is maintained at normal body 'core' temperature (as occurs in cryptorchidism or through tight clothing). The temperature of the testes is normally maintained about 2°C lower than core body temperature because they lie outside the body, moving freely in the scrotal sac. Three layers of membranes enclose each testis and extensions of the fibrous tunica albuginea form septa that divide the gland into 200300 lobes. In appearance, the testes are white with an oval shape (approximately 4 × 2 × 3 cm with a volume of about 25 ml and weighing between 1014 g). Seminiferous tubules constitute 7080% of this mass and each testis has approximately 200 m of seminiferous tubule. The blood supply comes from the testicular arteries that are branches of the internal spermatic arteries.\n\nA fully functioning testis normally achieved by the age of 16 years has the capacity to produce over 200 million sperm each day. Only one is required for fertilization, but each tiny sperm (a few thousandths of a millimeter in length) must travel some 3040 cm (100 000 times its own length) of the male and female reproductive tract before it reaches its final destination in the Fallopian tube. Less than 1 in a million ever completes this journey, though they are helped by the process of ejaculation.\n\nClinical Case 6.6 had normal Leydig cell function but clear evidence that his Sertoli cells had been damaged resulting in loss of spermatogenesis and infertility. There are a number of causes of this  but it is highly likely given his past medical history that the cytotoxic drug cyclophosphamide was the cause. Clinical Case 6.6 underwent testing of his seminal fluid and it was found that he had azoospermia (Treatment is possible in a number of causes of male infertility  but currently there is none available for cyclophosphamide-induced azoospermia. Cryopreservation of ovary and
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I assume you are referring to the centriole, which is found in the nucleus and is responsible for the organization and migration of chromosomes during cell division. They have functions that are not quite understood that allow them to organize and coordinate microtubule assemblies, just like a computer but on a much smaller scale.