Biology : Reproduction in Humans

• Report rights infringement
• published: 20 May 2015
• views: 59

High School Biology (Grade 10) Biology : Reproduction in Humans Reproduction (or procreation) is the biological process by which new individual organisms – "offspring" – are produced from their "parents". Reproduction is a fundamental feature of all known life; each individual organism exists as the result of reproduction. There are two forms of reproduction: asexual and sexual. (0:05 - 2:44) Fission : In biology, fission is the division of a cell (or body, population, or species) into two or more parts and the regeneration of those parts into separate cells (bodies, populations, or species. (2:45 - 4:31) Budding : Budding is a form of asexual reproduction in which a new organism develops from an outgrowth or bud due to cell division at one particular site. Regeneration : It is the process of renewal, restoration, and growth that makes genomes, cells, organisms, and ecosystems resilient to natural fluctuations or events that cause disturbance or damage. Fragmentation : Fragmentation or clonal fragmentation in multicellular or colonial organisms is a form of asexual reproduction or cloning in which an organism is split into fragments. Spore Formation : A mode of reproduction resembling multiple fission, common among Protozoa, in which the organism breaks up into a number of pieces, or spores, (4:32 - 8:50) Sexual Reproduction in Flower : Sexual reproduction involves two fundamental processes: meiosis, which rearranges the genes and reduces the number of chromosomes, and fertilization, which restores the chromosome to a complete diploid number.The evolutionary origin and adaptive significance of sexual reproduction are discussed in the pages “Evolution of sexual reproduction” and “Origin and function of meiosis.” (8:51 - 12:32) Human Female Reproductive System : The female reproductive system is designed to carry out several functions. It produces the female egg cells necessary for reproduction, called the ova or oocytes. The system is designed to transport the ova to the site of fertilization. Conception, the fertilization of an egg by a sperm, normally occurs in the fallopian tubes. The next step for the fertilized egg is to implant into the walls of the uterus, beginning the initial stages of pregnancy. If fertilization and/or implantation does not take place, the system is designed to menstruate (the monthly shedding of the uterine lining). In addition, the female reproductive system produces female sex hormones that maintain the reproductive cycle. (12:33 - 14:14) Human Male Reproductive System : The male reproductive system consists of a number of sex organs that form a part of the human reproductive process. In this type of reproductive system, these sex organs are located outside the body, around the pelvic region.The main male sex organs are the penis and the testicles which produce semen and sperm, which, as part of sexual intercourse, fertilize an ovum in the female's body(14:15 - 15:50) Fertilzation in Humans : During each normal menstrual cycle, one egg (ovum) is usually released from one of the ovaries, about 14 days after the last menstrual period. Release of the egg is called ovulation. The egg is swept into the funnel-shaped end of one of the fallopian tubes.At ovulation, the mucus in the cervix becomes more fluid and more elastic, allowing sperm to enter the uterus rapidly. Within 5 minutes, sperm may move from the vagina, through the cervix into the uterus, and to the funnel-shaped end of a fallopian tube—the usual site of fertilization. The cells lining the fallopian tube facilitate fertilization.If a sperm penetrates the egg, fertilization results. Tiny hairlike cilia lining the fallopian tube propel the fertilized egg (zygote) through the tube toward the uterus. The cells of the zygote divide repeatedly as the zygote moves down the fallopian tube. (15:51 - 16:58) Stage in the Early Development of the Embryo : Once a month, an egg is released from an ovary into a fallopian tube. After sexual intercourse, sperm move from the vagina through the cervix and uterus to the fallopian tubes, where one sperm fertilizes the egg. The fertilized egg (zygote) divides repeatedly as it moves down the fallopian tube to the uterus. First, the zygote becomes a solid ball of cells. Then it becomes a hollow ball of cells called a blastocyst. Inside the uterus, the blastocyst implants in the wall of the uterus, where it develops into an embryo attached to a placenta and surrounded by fluid-filled membranes. (17:00 - 21:14) Click on the Link for online Video for Biology : https://youtu.be/4G4VU5DCufg Video by Edupedia World (www.edupediaworld.com), Online Education, All Right Reserved.