Human Reproduction Sources for your Essay

Human Reproduction: Conception, Embryonic and


"Reproduction is not a continuous activity and is subject to certain patterns and cycles. Oftentimes these patterns and cycles may be linked to environmental conditions which allow organisms to reproduce effectively" (Bailey, 2010, Sexual reproduction)

Human Reproduction: Conception, Embryonic and


"Reproduction is not a continuous activity and is subject to certain patterns and cycles. Oftentimes these patterns and cycles may be linked to environmental conditions which allow organisms to reproduce effectively" (Bailey, 2010, Sexual reproduction)

Human Reproduction: Conception, Embryonic and


The second trimester, after week 12, is defined as a hypertropic phase of development. The organs developed in the first semester grow bigger, even though the seeds of development have been sown and "except for certain parts of the brain and lungs, all the cells the baby will ever have are there" by now (Bontragaer 2005, p

Human Reproduction: Conception, Embryonic and


As in reptiles and all mammals fertilization takes place inside the body of the female. "This technique increases the chances of successful sexual reproduction" (Freudenrich 2010, p

Human Reproduction: Conception, Embryonic and


If you are having a boy, testosterone starts being produced when you are about seven weeks pregnant, prompting the bud to grow and develop into a penis and scrotum. In a girl the genital nub will become the clitoris and labia" (Hammonds 2009)

Human Reproduction: Conception, Embryonic and


"From the child's viewpoint he or she is about as dependent as any in the placental mammals. This dependency is extraordinarily prolonged and the child requires parental care for many years" (Johnson 2010)

Human Reproduction: Conception, Embryonic and


However the mean is about 4 mm. Even this can produce an adequate increase in the total area of the pelvic outlet" (Jordon 1996)

Human Reproduction: Conception, Embryonic and


Having a greater variety of genetic combinations circulating in the gene supply allows more potentially adaptive responses to the environment to manifest. If there is a sudden change in the environment, genetically mutated offspring may survive better: for example, during the Industrial Revolution, a particular species of light-colored moth with dark mutations was able to survive because of the presence of dark-colored mutated moths within its gene pool which were able to camouflage themselves from predators due to the soot of industrialization (Miller 1999)

Human Reproduction: Conception, Embryonic and


The blastocyst is distinct from an embryo because it "represents such an early stage of embryonic development that the cells it contains have not yet differentiated, or taken on the properties of particular organs or tissues…kidneys, muscles, spinal cord, and so on. This is why the stem cells that are extracted from the blastocyst hold the promise of developing, with proper coaxing in the lab, into any kind of cell the researcher wants to study or repair" (Sandel 2009)

Human Reproduction: Conception, Embryonic and


Half of the genetic information comes from the mother's egg and half from the father's sperm. The zygote spends the next few days traveling down the fallopian tube and divides to form a ball of cells" (Vorvick 2009)