Describe the process of spermatogenesis if you are male and oogenesis if you are female.?
492746
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
318041
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.
630962
Human egg is called an Ovum. Please check the below link:\n\nhttp://www.womenshealthmatters.ca/Centres/sex/femalebody/men_stages.html
750284
Meiosis occurs after sexual maturity in both male and females.\nIn males in happens almost all the time after maturity, as males need to produce millions of sperm.\nIn females it happens approximately once a month and happens much more slowly, producing one gamete (egg or oocyte) for use.
51956
It's not a theory, this is a scientific statement or fact.  Theories are things like gravity and evolution, which can not be completely proved but have a large body of evidence backing it up.  I don't know of a term to describe this.  Gametes are haploid and the process of forming gametes in mammals is spermatogenesis and oogenesis, which are meiotic cycles.
197235
Female- Eggs\nMale- sperm\n\nEggs are made from their stem cells when the female is still in the womb, and then develop when the female goes through puberty.\n\nSperm are made when the male goes through puberty.\n\nThis is for humans, I am unsure of how other organisms do it.
493326
The best anyone can do is offer a guess--no one knows for sure.  We do know that all human fetuses begin development as females, and only become male when they are exposed to male hormones while they develop.  Ovaries and testes are initially the same structure, but they develop into different things based upon the fetus' genes.  If they develop into testes, the fetus starts producing testosterone.  This also determines whether another structure develops into a penis or a clitoris, and my guess is that it also determines whether breast tissue becomes enlarged and develops milk-producing tissue.  So my short answer is, men have teats because for a little while in the womb, they were actually women.  Isn't it strange how our bodies work?
320679
B. Secondary spermatocytes... spermatids are the product of the meiosis II which under go metamorphosis to become spermatozoa, but they don't go through meiosis again
973826
Meiosis is the type of cell division by which germ cells (eggs and sperm) are produced. Meiosis involves a reduction in the amount of genetic material.\n\nMeiosis comprises two successive nuclear divisions with only one round of DNA replication.\nFour stages can be described for each nuclear division.
399821
Forever. Dude you just had your manhood sliced ... you can't ever recover from that. In fact have a vasectomy practically makes you a woman. It's true. Men can produce sperm, you know who can't? Women - and guys who've had a vasectomy.
54165
Actually, women do have them, they're called ovaries.       The tissue that goes on to become testicles in a male fetus develops into ovaries in a female fetus.  Both the ovaries in a female and the testicles in a male produce gametes (eggs vs. sperm) and hormones.
526164
Meiosis:  \nprocess of cell division which occurs in the maturation of sex cells (Biology).\n\nMitosis:\nprocess of cell division resulting in two daughter cells which are identical to the original nucleus (Biology).
696921
Meiosis is the type of cell division by which germ cells (eggs and sperm) are produced. Meiosis involves a reduction in the amount of genetic material
124945
It depends on the technique employed and the species involved.\n\nIf u carry out chromosome analysis, it's from right after fertilization.\n\nFor human, sexual differentiation occours ~6 weeks after fertilization.
25734
Every egg starts developing in the womb as a female. The male genes kick in only later during the gestation. Consequently, an egg developing into a foetus develops nipples. After a certain stage, when the male genes kick in, the development of the breast is stopped. Thus men have nipple but don't have breast.
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.
616416
Sperm and Egg cells are different in a number of ways:\n1. They are haploid cells: that is, they have half the normal number of chromosomes;\n2. They are formed from meiosis: this is the immediate cause of #1;\n3. They are formed from spermatocytes and oocytes\n4. They can create a new member of their species.