Reproduction :: essays research papers

THE REPRODUCTIVE SYSTEMThe ability to puke is unitary of the unifying characteristics of all living things. Sexual procreation make grows offspring that atomic number 18 genetically different from their p arnts. Asexual reproduction make grows offspring genetically resembling to their p atomic number 18nt. Asexual ReproductionFission, budding, fragmentation, and the formation of rhizomes and stolons are some of the mechanisms that allow organisms to re mother asexually. The hydra produces buds starfish passel regenerate an entire body from a fragment of the original body. Asexual reproduction allows an organism to rapidly produce many offspring without the time and resources committed to courtship, finding a mate, and mating. The privation of genetic variability in asexually reproducing populations can be damaging when environmental conditions change quickly.Sexual ReproductionIn sexual reproduction new individuals are produced by the uniting of haploid gametes to form a diploid zygote. Sperm are male gametes, ova are female gametes. litotes produces cells that are genetically distinct from each other fertilization is the fusion of two such distinctive cells that produces a unique new combining of alleles, and then increasing variation on which natural selection can operate. Rotifers will reproduce asexually when conditions are favorable by having females produce eggs by mitosis. When conditions deteriorate, rotifers will reproduce sexually and encase their zygotes inwardly a resistant shell. Once conditions improve, these eggs hatch into diploid individuals. Rotifers thus use sexual reproduction as way to survive a deteriorating environment.Sexual reproduction offers the benefit of generating genetic variation among offspring, which enhances the chances of the populations survival. Costs of this bidding include the need for two individuals to mate, courtship rituals, as well as a number of basic mechanisms described later. Human Reproduction an d emergenceHuman reproduction employs internal fertilization, and depends on the integrated action of hormones, the scatterbrained system, and the reproductive system. Gonads are sex organs that produce gametes. Male gonads are the testes, which produce sperm cell and male sex hormones. Female gonads are the ovaries, which produce eggs and female sex hormones. The Male Reproductive SystemTestes are suspended outside the abdominal cavity by the scrotum, a sackful of skin that keeps the testes close or far from the body at an optimum temperature for sperm get outment. Seminiferous tubules are inner each testis, and are where sperm are produced by meiosis. About 250 meters (850 feet) of tubules are packed into each testis. Spermatocytes inside the tubules divide by meiosis to produce spermatids that in turn develop into mature sperm.