Biological Questions Biological Questions

Mitosis and Meiosis
Mitosis involves the process that the eukaryotic cell separates the
chromosomes from the cell nucleus into two constituent and identical
sets. Essentially, the mother cell divides into identical daughter cells
similar to the mother cell by all dimensions. On the other hands,
Meiosis is a type of cell division that is necessary for sexual
reproduction where a cell that contains two sets of each chromosome. Of
the two copies, one is from the mother while the other one is from the
father (Snustad & Simmons, 2008). Through this process, the zygote
produces four cells that contain one copy chromosome each. The most
notable difference between the two is that, mitosis is used for the
organic growth of tissues and is the reproductive process used by single
celled organisms. On the other hand, meiosis is a useful process for
sexual reproduction where the male and female sex cells fuse to create a
new biological organism.
Secretion of FSH and LH
In females, the pulse frequency as well as amplitude of GnRH change
during the process of the ovarian cycle. In consideration of changes in
the pulse frequency the effects are both dramatic but are controlled by
circulating levels of progestins and estrogens. Estrogens will always
increase the GnRH pulse frequency while progestins tend to decrease it.
The adenohypophysis endocrine cells normally respond in a way that shows
that each group the cells is monitoring diverse frequencies (Raven,
Johnson, Mason, Losos & Singer, 2007). Due to this, each set of the
cells remains sensitive to both the GnRH pulse frequencies and to other
cells. A good example is the gonadotropes that are responsible for the
production of FSH and LH (Raven et al, 2007). The gonadotropes respond
preferentially at one pulse frequency and they secrete FSH. At another
frequency, the gonadotropes respond differently and release LH as the
primary hormone. This way, production of FSH and LH occurs in pulses
based on the rhythm of GnRH pulses. This means that FSH and LH secretion
will gradually stop if GnRH is supplied at a constant rate without the
pulse rate or is absent (Snustad & Simmons, 2008).
After Vasectomy
Immediately after the procedure of vasectomy, the patient should expect
to be relatively mild in terms of any discomfort. This is so especially
after a no-scalpel vasectomy. After the local anesthesia wears off after
around an hour the doctor will advise on the appropriate pain relievers
as well as antibiotics. Before being discharged, the patient should read
the doctor’s written instructions together with the spouse in order to
follow general guidelines for recovery as well as comfort. After a few
days the patient will experience a little swelling including some little
discomfort. This usually goes for a week but if the experience is too
much pain for the patient, consulting a doctor would be the best option.
Spermatogenesis
Spermatogenesis is the reproductive process through which the male
primordial germ cells produce spermatozoa through mitosis and meiosis.
Spermatogonia are the primary cells in this pathway and they yield
primary spermatocytes through the process of mitosis. After the
yielding, the primary spermatocyte divides through the process of
meiosis into two spermatocytes. After this, each of the spermatocyte
then completes the meitosis process and divides into two spermatids
(Snustad & Simmons, 2008). These spermatids then develop into mature
spermatozoa that are referred to as sperm cells. This way, the primary
spermatocyte develops and eventually gives rise to two cells. The two
cells are the secondary spermatocytes which also subdivide to produce
four spermatozoa.
Hormones and Ovulation
According to Raven et al. (2007), the hormone that stimulates the
primary growth of the follicle is the Follicle stimulating hormone. This
is active during the follicular phase of the process of menstruation and
not the ovulation phase. The process of ovulation occurs after the
follicle bursts to release a mature ovum into the fallopian tubes
(Snustad & Simmons, 2008). This is process is stimulated by a spike of
luteinizing hormone when the cycle is 14 days mature. Despite the FSH
spiking at such a time in process, it is not actually the hormone that
is responsible for the ovulation process.
Contraceptive Pill “Tricks the brain”
It is clear that, aside as from being a contraceptive, the BCP (Birth
Control Pill), fundamentally alters the way a woman body ought to
function. As indicated by Zonderman et al. (2009), the pill basically
makes the woman`s body respond and behave as if it is constantly under
pregnancy. When this body behavior “works” it disrupts a woman’s
body from following the normal natural hormonal cycle thereby preventing
her from getting pregnant (Zonderman et al., 2009). Further, the BCP can
also act as abortifacient (Zonderman et al., 2009). Although one of its
roles is to thin the uterus lining thus making it hard for the
fertilized egg to be implanted, it has often failed to serve its
purpose. This is due to the inability of most women to precisely
indicate their usual menstrual cycle (Zonderman et al., 2009).
References
Raven, P.H, Johnson, B., Mason, A., Losos, J & Singer, S (2007).
Biology, 8th ed. McGraw-Hill.
Snustad, D & Simmons, M (2008). Principles of Genetics (5th ed.). Wiley.
Zonderman, J.et al. (2009). Birth Control Pills. Infobase Publishing
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