How do the products of spermatogenesis and oogenesis differ?
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asymetric cytokinesis in oocytes.
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Capacitation: readying the sperm\nSperms cannot fertilize oocytes when they are newly ejaculated. \nThe process of capacitation takes 5-7 hours. \nCapacitated sperms are more active. \nLocation: capacitation occurs in the uterus and oviducts and is facilitated by substances of the female genital tract. \nThe acrosomal reaction cannot occur until capacitation has occurred.
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The capacitated spermatozoon and the oocyte meet and interact in the ampulla of the fallopian tube. In mammals, binding of the spermatozoon to the zona pellucida, an extracellular layer surrounding the oocyte, initiates the acrosome reaction. This process releases the enzyme hyaluronidase, which digests the matrix of hyaluronic acid in the vestments surrounding the oocyte. Fusion between the sperm and oocyte plasma membranes follows, allowing the entry of the sperm nucleus, mitochondria, centriole and flagellum into the oocyte. Once the ovum fuses with a single sperm cell, its cell membrane changes, preventing fusion with other sperm.\n\nThis process ultimately leads to the formation of a diploid cell called a zygote. When the zygote reaches the uterus and implants in the endometrium, the female is said to be pregnant.\n\nIf fertilisation takes place, the sperm usually meet the ovum in the fallopian tube, requiring the sperm cells to swim from the upper vagina through the cervix and across the length of the uterus before reaching the fallopian tube—a considerable distance compared to the size of the sperm cell.\n\n\nFertilization in plants\n\nAfter the pistil is pollinated, the pollen grain germinates in a response to a sugary fluid secreted by the mature stigma. From each pollen grain, a pollen tube grows out attempting to travel into the ovary by creating a path. The vegetative and generative nuclei of the pollen grain pass into its respective pollen tube. The growth of the pollen tube is controlled by the vegetative nucleus. Enzymes are secreted to digest the tissue of the stigma a style as the polen tube grows. The pollen tube does not directly reach the ovary in a straight line. It travels near the skin of the style and curls to the bottom of the ovary, then near the receptacle, it breaks through the ovule through the microphyle (an opening in the ovule wall) and reaches the ovum to fertilise it. This is the point when fertilisation actually occurs. After being fertilised, the ovary starts to swell and becomes a fruit.\n\nWith multi-seeded fruits, multiple grains of pollen are necessary for syngamy with each ovule. The process is easy to visualise if one looks at maize silk, which is the female flower of corn. Pollen from the tassel (the male flower) falls on the sticky external portion of the silk, and then pollen tubes grow down the silk to the attached ovule. The dried silk remains inside the husk of the ear as the seeds mature; if one carefully removes the husk, the floral structures may be shown. The development of the flesh of the fruit is proportional to the percentage of fertilised ovules. For example, with watermelon, about a thousand grains of pollen must be delivered and spread evenly on the three lobes of the stigma to make a normal sized and shaped fruit.
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Male reproductive organs or male reproductive system \n\nThe main reproductive organs of the male body are the testes, which produce sperm and also male hormones, in the form of testosterone. The male reproductive system also includes the external genitals — the penis and the scrotum — and the internal structures, including the prostate gland, the vas deferentia (plural for the 2 vas deferens), the urethra, and the seminal vesicles.\n\nTestes\nThe paired oval testes, also known as the male gonads, hang in the scrotal sac. Usually the right testis hangs higher than the left one by about 1 cm. The testes hang outside the body because the temperature inside the body is too high to produce sperm, so they are produced in the testes at about 3 °C lower than body temperature.\n\nEpididymis\nAt the back of the olive-shaped body of each testis is a cap formed by the many coils of a 20-foot long tube called the epididymis. The function of the epididymis is to collect the immature sperm from the testis.\n\nAs the sperm make their long journey through the epididymis they become mature sperm. This journey takes about 20 days and during its course the sperm become fertile and they also become able to move in a swimming motion (doctors refer to the sperm then as ‘motile’).\n\nVas deferens\nJoined to the epididymis is the vas deferens — a thick walled tube which transports sperm from the epididymis up to the prostate gland. The section of the vas deferens that is above the testis can be felt through the loose part of the scrotum. When a vasectomy is performed, it is this part of the vas deferens that is snipped.\n\nThe vas deferens empties into the ejaculatory duct, which passes through the prostate gland to merge with the urethra.\n\nThe urethra\nThe urethra serves as the tube down which urine passes from the bladder through the penis to the outside and also the tube down which semen is ejaculated.\n\nThe prostate\nThe prostate is a walnut-shaped gland that surrounds the urethra. Along with the seminal vesicles it produces the fluid secretions that support and nourish the sperm. Without this fluid to dilute them the sperm cannot move easily.\n\nAfter the age of 40 the prostate enlarges and can press on the urethra. An enlarged prostate is often the cause of urinary problems in older men.
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Polar body is a cell structure found inside an ovum. Both animal and plant ova possess it.\n\nAsymetrical cell division (cytokinesis) leads to the production of polar bodies during oogenesis. To conserve nutrients, the majority of cytoplasm is segretated into either the secondary oocyte or ovum, during meiosis I or meiosis II, respectively. The remaining daughter cells generated from the meiotic events contain relatively little cytoplasm and are referred to as polar bodies. Eventually, the polar bodies degenerate.\n\nThere may be either one or two inside the ovum, usually two. During meiosis, an oocyte divides, of which one will continue to develop into an ovum, the others becoming polar bodies. The first polar body comprises one of the two products in the first stage of meiosis and is haploid, but since each chromosome still has two chromatids, it has twice as much DNA as the second polar body. Both are relatively small and contain little cytoplasm. This second polar body can potentially result in half-identical twins, when the second polar body does not disintegrate and is fertilized by a sperm.\n\nIn plants, the pollen releases two male gametes into the ovule upon fertilization. One fertilizes the haploid ovum and develops into a normal embryo, while the other fertilizes the two polar bodies within the center of the ovary, creating a structure called endosperm. Endosperm stores nutrients for initial growth of plant seeds. Cereal grain is an example of this, and is consumed for its nutritional value by most animals including humans.
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your answer should be --- mamalian or human reproduction. depends on if this is a question for a subject being studied or not, and what subject it is.\n\nbecause the zygote is the cell that is formed by the fusion of two haploid gametes, one from a male and one form a female.\n\nafter the first diploid cell is created, it is no longer reproduction, but embryonic development, since there are more than one cell once they start dividing, and they all are diploid.\n\nin most other reproductive processes, the gametes contain more than one set of chromosomes, making the gametes polyploid rather than haploid, therefore, the zygote isn't diploid.
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Mitosis is when a cell divides to create two daughter cells that are identical. Meiosis is the process by which eggs and sperm are created. In meiosis a cell divides and each daughter cell has only half the DNA.
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An anther and a filament.  The anther makes pollen which contain the male's reproductive cells.
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It's an oversimplification to say that pollen is a plant's sperm:\n\nPollen grains are structures that house the male gametophyte generation of angiosperms and gymnosperms (seed plants).  They are also the vehicles in which the male gamete genetic code is carried to the female gamete.  Pollen grains develop in the anther in angiosperms.  It travels and is deposited on the stigma of a receptive flower.  In gymnosperms, pollen develops in the male cone, travels, and fertilizes the ovules in the female cones to produce seeds.  Each pollen grain consists of the two celled male haploid plant enclosed in a thickened wall.
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For men of normal fertility, sperm creation is a constant, ongoing process. Millions of sperm cells are created each day in the testes; they mature in one to 3 months, after which they're ready to be ejaculated. So, since there are always sperm cells being made, there is a lot of overlap between your "loads." Once one has been released, another should not be far behind.\nActual semen quantity differs among individuals and can also change for the same individual during different times of his life. Genetics plays an important part in how much a male will ejaculate. Most males ejaculate about one teaspoon of semen. Some medications may affect the amount of semen produced. And you will notice that the longer you take between orgasms the larger the quantity of semen you will ejaculate. (You've probably noticed that if you masturbate more than once a day that the second, third or fourth time you achieve orgasm you release smaller and smaller quanitities of semen. Wait overnight and see how much more your body made while you were asleep.) Additionally, the more aroused you get and the longer you take to ejaculate, the more semen your body will produce. Foreplay — touching yourself in special ways in special places — will sometimes stimulate the body to produce more semen, since the body's reproductive glands (such as the prostate) work harder when you're aroused.\nSemen appearance and texture can change naturally over the course of months, days, or even from one ejaculation to another, due to a variety of factors inculding diet.\nSemen from a mature male is usually a milky or pearly-white color. It is not uncommon to see a yellowish tint to the semen if you've abstained from ejaculation for a while. Semen colored with red streaks may signify blood. If you occasionally see a bit of blood it's not necessarily a cause for alarm, but if you see a lot of it, or if it persists, the condition should be brought to the attention of your physician. The same goes any other drastic color changes, which may indicate infection. \nA lot of factors go into the appearance and consistency of semen, including diet, ejaculation frequency, etc., so changing any of these can alter the way your semen looks. Also, it's easy to think that semen is simply sperm cells in water, but it's a much more complex substance than that. So it may have been the absence or presence of something other than actual sperm cells — such as sugars or proteins — that caused your semen to look different before.\nA nocturnal ejaculation may have more prostatic fluid in it (which is whiter and thicker), while a daytime ejaculation may have more sperm and fluid from the seminal vesicles, which tends to be more clear and less viscous.
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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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Sperm and ova are unfertilized gametes with 1 set of chromosomes, therefore known as haploid cells (n). They combine to form the fertilized cell, zygote, which is a diploid cell (2n) with 46 chromosomes. Meiosis is the process that halves the chromosomes numbers and fertilization is the process that restores it.
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meiosis (mīŏ'sĭs) , process of nuclear division in a living cell by which the number of chromosomes is reduced to half the original number. Meiosis occurs only in the process of gametogenesis, i.e., when the gametes, or sex cells (ovum and sperm), are being formed. Because fertilization consists of the fusion of two separate nuclei, one from each of the sex cells, meiosis is necessary to prevent the doubling of the chromosome number in each successive generation. An ordinary body cell is diploid; i.e., it contains two of each type of chromosome. The members of each pair are known as homologous chromosomes. An ovum or sperm is haploid; i.e., it contains only a single chromosome of each type and, therefore, half the number of chromosomes of the diploid cell. When the two haploid cells fuse, the diploid number is restored, and the plant or animal growing from the fertilized egg (zygote) has the usual diploid number of chromosomes in its cells. Just before meiosis each chromosome replicates to form two identical copies in the form of strands called chromatids joined together at a point called the centromere. In the first stage of meiosis, called the reduction division, the members of each pair of homologous chromosomes lie side by side and crossing over occurs. Each member of the pair then moves away from the other toward opposite ends of the dividing cell, and two nuclei, each with the haploid number of double-stringed chromosomes, are formed. Thus at the beginning of the second meiotic sequence, called the equational division, each cell nucleus contains one chromosome from each homologous pair and each chromosome is of two strands that are identical (except where crossing over has occurred). Then the chromosomes separate into their single strands which move toward opposite ends of the dividing nucleus. The result of meiotic division is four cells, each haploid, with one chromosome of each pair.
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Pls refer below link..\n\nhttp://kidshealth.org/parent/medical/body_basics/male_reproductive.html\n\nCheers!!!
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The process by which immature eggs in the ovary mature is called oogenesis. This process consists of two phases of meiosis. During each of these phases a polar body is produced. In the case of humans, they are not important to reproduction. In some species they do play a role in the maturation of the egg. IFor each oocyte produices three polar bodies are created that later disintegrate.
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Meiosis is the process that transforms one diploid cell into four haploid cells in eukaryotes in order to redistribute the diploid's cell's genome.\n\nMeiosis forms the basis of sexual reproduction and can only occur in eukaryotes. In meiosis, the diploid cell's genome, which is composed of ordered structures of coiled DNA called chromosomes, is replicated once and separated twice, producing four haploid cells each containing half of the original cell's chromosomes. These resultant haploid cells will fertilize with other haploid cells of the opposite gender to form a diploid cell again. The cyclical process of separation by meiosis and genetic recombination through fertilization is called the life cycle. The result is that the offspring produced during germination after meiosis will have a slightly different blueprint which has instructions for the cells to work, contained in the DNA. This allows sexual reproduction to occur.\n\nMeiosis uses many biochemical processes that are similar to those used in mitosis in order to distribute chromosomes among the resulting cells; however the outcome is very different.
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This sounds like a homework question. Think about it this way: what does diploid mean, and what does haploid mean? What has to happen for a gamete to form? How many chromosomes in a haploid gamete as opposed to a diploid somatic cell? What happens at fertilization? How many chromosomes would be in a fertilized zygote if you count up what was in each gamete?\n\nHints: a gamete is an egg or sperm; a somatic cell is any cell that is not a gamete; a zygote is what is formed when egg and sperm combine in fertilization. Post again if you're still stuck.