Reproductive System

The Process of Fertilization

The fertilization process is a marvel of nature which ensures the continuity of distinctive species from one generation to the next. In basic terms, fertilization is a process that entails the fusion of male sperm and female ovum which are also referred to as haploid gametes (Immler & Otto, 2018). The present state of technological developments have allowed for subtle variations in the manner fertilization occurs. However, the goal of the fertilization process is to achieve the production of a diploid zygote (Immler & Otto, 2018). This happens when during sexual intercourse; the male organ ejaculates potent sperms into a female organism’s reproductive system. For fertilization to occur, the moment for copulation has to be just right such that the female egg is ripe (Corner, 2015). Once deposited into the female reproductive system, the conditions within allow for the sperms to swim towards the fallopian tubes where the ovum is located (Corner, 2015). Although numerous sperms reach the ovum, it takes only one to complete the fertilization process.

Compare and Contrast Oogenesis and Spermatogenesis

In the human beings, two forms of reproductive divisions take place. In sexually developed male and female beings, sexual reproductive systems undergo the gametogenesis process which occurs within the germ cells located within gonads. Meiosis facilitates haploid gamete production within the diploid germ cell (Walpole, 2015). However, there are predominant differences between the male and female gamete. The male gamete is known as the sperm while the female gamete is the ovum. The underlying dissimilarity between the two is that spermatogenesis entails the production of sperms within the male germ cells called spermatogonia (Walpole, 2015). Conversely, oogenesis refers to the generation of eggs or ova from within the female germ cells referred to as oogonia.  All stages that unfold during spermatogenesis occur within the male testicles while those witnessed during oogenesis takes place within the ovaries in the female reproductive system (Walpole, 2015). Spermatogenesis differs from oogenesis since the latter begins at puberty and does not cease until death while oogenesis is initiated in the unborn fetus but is fully completed after puberty and continues until menopause sets in. Sperms are produced from the seminiferous tubules within the testes that contain a germinal epithelial lining that hosts sertoli cells (Walpole, 2015). In oogenesis, the ovaries overlaid with germinal epithelium contain no sertoli cells ensuring that eggs are generated through a prolonged growth phase. Spermatogonia growth phase is not only very short but also involves the meiosis process towards the production of mobile gametes (Walpole, 2015). Eggs are stationary gametes also produced through meiosis which results in a secondary oocyte as well as a single polar body.

How Estrogen and Testosterone Affect the Body

The pituitary gland is responsible for the production of estrogen and testosterone in the body. However, this only occurs after an individual has reached puberty (Melmed, 2016). Testosterone serves to stimulate the development of the male’s sexual capacities. Testosterone as a hormone is derived from the androgen family and one of its primary purposes is for the maintenance of the masculine reproductive system (Melmed, 2016). In men, testicles generate androgen while ovaries as well as adrenal glands produce little amounts of testosterone and other androgens that promote for masculinity in the body. In teenage boys, the pituitary gland releases a hormone that stimulates testicles to generate increasing testosterone quantities that among other things support sperm production in males. Estrogen is a hormone developed from cholesterol and serves to allow for development of feminine features in females (Melmed, 2016). In the teenage years, the female body’s ovaries secrete increasing estrogen levels that allow among other things for the maturation of sexual organs in readiness for the fertilization process.

References

Corner, G. W. (2015). Hormones in human reproduction. Princeton, NJ: Princeton University Press.

Immler, S., & Otto, S. P. (2018). The evolutionary consequences of selection at the haploid gametic stage. The American Naturalist, 192(2).

Melmed, S. (2016). Williams textbook of endocrinology. New York, NY: Elsevier Health Sciences.

Walpole, B. (2015). Biology for the IB Diploma Exam Preparation Guide. New York, NY: Cambridge University Press.