animation of reproduction in humans
Best Results From Wikipedia Yahoo Answers Youtube
Human reproduction is any form of sexual reproduction resulting in the conception of a child, typically involving sexual intercourse between a man and a woman. During intercourse, the interaction between the male reproductive system and the female reproductive system results in fertilization of the woman's ovum by the man's sperm, which after a gestation period is followed by childbirth. The fertilization of the ovum may nowadays be achieved by artificial insemination methods, which do not involve sexual intercourse.
The human male
The male reproductive system contains two main divisions: the penis, and the testes, the latter of which is where sperm are produced. In humans, both of these organs are outside the abdominal cavity. Having the testes outside the abdomen best facilitates temperature regulation of the sperm, which require specific temperatures to survive.
The human female
The female reproductive system likewise contains two main divisions: the vagina and uterus, which act as the receptacle for the semen, and the ovaries, which produce the female's ova. The vagina is attached to the uterus through the cervix, while the uterus is attached to the ovaries via the Fallopian tubes. At certain intervals, the ovaries release an ovum, which passes through the fallopian tube into the uterus.
If, in this transit, it meets with Spermatozoon, the sperm penetrate and merge with the egg, fertilizing it. The fertilization usually occurs in the oviducts, but can happen in the uterus itself. The zygote then implants itself in the wall of the uterus, where it begins the processes of embryogenesis and morphogenesis. When developed enough to survive outside the womb, the cervix dilates and contractions of the uterus propel the foetus through the birth canal, which is the vagina.
The ova, which are the female sex cells, are much larger than the spermatozoon and are normally formed within the ovaries of the fetus before its birth. They are mostly fixed in location with in the ovary until their transit to the uterus, and contain nutrients for the later zygote and embryo. Over a regular interval, in response to hormonal signals, a process of oogenesis matures one ovum which is released and sent down the Fallopian tube. If not fertilized, this egg is flushed out of the system through menstruation.
Human reproduction is a long process, starting with sexual intercourse, followed by nine months of pregnancy before childbirth. Many years of parental care is required in order to finish with a mature human being.
Human reproduction takes place as internal fertilization by sexual intercourse. During this process, the erectpenis of the male is inserted into the female'svagina until the maleejaculates semen, which contains sperm, into the female's vagina. The sperm then travels through the vagina and cervix into the uterus or fallopian tubes for fertilization of the <
The female reproductive system (or female genital system) contains two main parts: the uterus, which hosts the developing fetus, produces vaginal and uterine secretions, and passes the male's sperm through to the fallopian tubes; and the ovaries, which produce the female's egg cells. These
From Yahoo Answers
Answers:different animals reproduce in different ways. Humans are a type of primate, primates are a type of mammal and mammals reproduce sexually. But not all animals are like that. Consider the earthworm. Look up how it works for them.
Answers:Organisms that reproduce through asexual reproduction tend to grow in number exponentially. However, because they rely on mutation for variations in their DNA, all members of the species have similar vulnerabilities. Organisms that reproduce sexually yield a smaller number of offspring, but the large amount of variation in their genes makes them less susceptible to disease. Many organisms can reproduce sexually as well as asexually. Aphids, slime molds, sea anemones, some species of starfish (by fragmentation), and many plants are examples. When environmental factors are favorable, asexual reproduction is employed to exploit suitable conditions for survival such as an abundant food supply, adequate shelter, favorable climate, disease, optimum pH or a proper mix of other lifestyle requirements. Populations of these organisms increase exponentially via asexual reproductive strategies to take full advantage of the rich supply resources. When food sources have been depleted, the climate becomes hostile, or individual survival is jeopardized by some other adverse change in living conditions, these organisms switch to sexual forms of reproduction. Sexual reproduction ensures a mixing of the gene pool of the species. The variations found in offspring of sexual reproduction allow some individuals to be better suited for survival and provide a mechanism for selective adaptation to occur. In addition, sexual reproduction usually results in the formation of a life stage that is able to endure the conditions that threaten the offspring of an asexual parent. Thus, seeds, spores, eggs, pupae, cysts or other "over-wintering" stages of sexual reproduction ensure the survival during unfavorable times and the organism can "wait out" adverse situations until a swing back to suitability occurs.
Answers:get a blood test done for std (sexual transmitted diseases )before performing sex without condoms ONLY way to be certain because there are diseases like Clamidia that cannot be noticed until you try to have babies and makes you infertile genetal herpies can be unnoticed as well and stay with you forever
Answers:What is absurd is the idea that a species has to evolve first, and *then* split into two sexes! Evolution provides a far more sensible answer ... the human species evolved from a long legacy of ancestral species that already had two sexes. Earlier primates, earlier mammals, earlier therapsids, earlier reptiles ... all species with two sexes ... but different levels of sexual dimorphism (secondary differences in size and characteristics) ... until we come to an ancestor that, yes, had both male and female organs. There is nothing "absurd" about that answer unless you already have decided that Evolution (common ancestry) is absurd, and *then* concluded that evolution of human reproduction is impossible. In other words, you are failing to see the how you have put the cart before the horse in your thinking. First you have decided that Evolution is "absurd" (apparently thinking that the world's biologists are morons because they have overwhelmingly accepted an "absurd" theory as the backbone of modern biology for 150 years). And *then* you characterize the details of evolution in truly absurd ways in order to justify your conclusion. So please, why don't you actually *ask* these questions to people who do not believe evolution to be absurd *before* reaching your conclusion. If hundreds of thousands of the world's brightest scientists for over 150 years ... people who live, eat, and breathe biology ... have accepted evolution as the central unifying theory of modern biology ... then even if you believe they are wrong ... they are not *absurdly* wrong. To believe they are is to call the entire scientific community nothing but a bunch of idiots. And calling the scientific community idiots doesn't give your argument much scientific credibility.