Mitosis Essays (Examples)

living things are characterized by the following seven characteristics namely mobility, respiration, excretion, sensitivity or response to external stimulus, growth, feeding, and reproduction. Though there may be variations between animal and plant kingdom (ex, plants take in carbon dioxide and prepare their own food), these characteristics are commonly observed among all living things.

iology is a very broad field that encompasses the study of characteristics of living things. It includes botany, zoology and all other sub-disciplines that range from microbiology to evolution and ecology.

Evolution is the branch of biology that deals with the study of natural development of living organisms and the changes in them over time. Evolution refers to the heritable changes that occur in a population over a period of time. All the diversity that is observed currently in plant and animal kingdom can be ascribed to evolution over a long period of time.

Atoms are the…

Bibliography

1) Mark Rothery, "Cells," Accessed on Sep 20th 2005, Available from http://www.mrothery.co.uk/cells/cellnotes.htm

Cell Division

All living things are complex organisms that are made up of cells. Some are made up of a single cell while others comprise of numerous cells working together. Cells are the basic functional and structural units of living organisms and are known to be the building blocks of life. In humans it is from a group of cells that tissues are made and from tissues that organs are made which enable beings to live.

Cells obtain food and oxygen through their membranes and each membrane has a specific area which can serve contents of only a given volume. Any increase in volume of the cell requires that the area of the membrane increases. Basically, when cells grow the membrane becomes insufficient in aiding the movement of substances in and out and thus to maintain a favourable surface area to volume ratio, cell division must take place. Furthermore, cell…

References

Bolsover, S., E. Shephard, H. White, and J. Hyams. Cell Biology: A Short Course. 3. Wiley-

Blackwell, 2011. 432.

Conger, Krista. "Scientists turn skin cells into neural precursors, bypassing stem-cell stage." Stanford School of Medicine. n. page. Print.

Morgan, David. The Cell Cycle: Principles of Control. New Science Press, 2007.

Apoptosis

Living organisms are truly fascinating not only for the ways they function within their larger environments, but also at the microscopic level in how they function in and of themselves. Ultimately, of course, these two views and understandings of organisms are wholly linked and entirely inseparable, as no organism would be able to function in the environment at large if it was not functioning properly at the microscopic level. Without muscle fibers properly contracting and expanding, it would be impossible for the human fingers to type away on a keyboard; without the proper nerve cells being triggered and the right neurons firing in the brain, a shark would be unable to smell, detect, and go after its prey; if blood cells were not permeable to the right substances in the right amounts, nutrients and necessary molecules couldn't be transported throughout the body as they were needed.

All of this…

References

Dash, P. (2011). Apoptosis. Reproductive and Cardiovascular Disease Research Group. Accessed 17 February 2011.  http://www.sgul.ac.uk/depts/immunology/~dash/apoptosis/ 

Department of Health & Human Services. (2005). Inside the cell. (NIH Publication No. 05-1051). Washington, DC: U.S. Government Printing Office.

Kimball, J. (2011). Apoptosis. Kimball's Biology Pages. Accessed 17 February 2011. http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/A/Apoptosis.html

However, recently, anesthesiologists have suggest a low to mid thoracic epidural combined with adequate general anesthesia. This anesthetic technique will allow for adequate inter-operative monitoring. After the operation, the anesthesiologist must continue to monitor the patient for either hypertension, hypotension and hypoglycemia. The presence of either of these conditions may alter the course of the medication given to the patient once the patient is removed from the anesthesia.

Respiratory System

Neurofibroma can cause systemic problems within the various components of the Respiratory System. As has already been presented, Neurofibromas can cause partial blockages within upper parts of the trachea. However, Neurofibromas can also pose challenges or the anesthesiologist when dealing with nasal, sinus or maxilofacial cavities with Neurofibromas present within. One example of how devastatingly complex the Neurofibroma can become is seen when a benign neurofibroma can cause a superior vena cava compression. Such was the case of a 21-year-old…

On average, male skeletons are larger than female skeletons, but just as some women are larger than some males, this distinction does not hold firm in all instances. Female pelvic regions tend to be wider than male pelvic regions, an evolutionary feature that has made childbirth easier. Female bones tend to be thinner and less dense than male bones, and thus the female skeleton tends to be lighter than male skeletons.

The skull is one of the most notable sites of difference between male and female skeletons. The teeth of males tend to be larger, and above their eye sockets men tend to have a more visible brow ridge while women often have none. The male skull tends to have a squarer (as opposed to a pointed) chin and is more angular in its demarcations than the female skull. Women's nose openings are more apt to be pointed, rather than…

References

The cell cycle & mitosis tutorial. (1997). The Biology Project. University of Arizona. Updated 2004. Retrieved February 10, 2010 at  http://www.biology.arizona.edu/Cell_bio/tutorials/cell_cycle/cells3.html 

Cell division via mitosis. (2010). Ivy Rose UK. Retrieved February 10, 2010 at  http://www.ivy-rose.co.uk/HumanBody/Cells/Cell-Division_Mitosis.php 

Richards, a. (2002). Male and female skeletons. Retrieved February 10, 2010 at http://transwoman.tripod.com/skeleton.htm

The main side effect of colchicines on animals is nausea. The use of colchicines on animals has also generated numerous concerns regarding the toxicity of bone marrow because of the ability of these substances to interfere with cell division. Furthermore, these substances are also likely to cause urine dip stick to wrongly read positive for blood. Colchicines can not only enhance the level of alkaline phosphatase as recorded on a blood chemistry panel but also diminish the body of vitamin B-12 in certain cases.

Since cytochalasins bind actin monomers and prevents their congregation into microfilaments, the already formed microfilaments slowly depolymerize. The main effect of these substances on animal cell division is that they inhibit cytoplasmic division but do not interfere with nuclear division or DNA synthesis. As a result, these substances contribute to the accumulation of large multi-nucleate cells (Gurdon & Fairman, p. 78.). In addition to the probability…

Works Cited:

"Colchicine." Mar Vista Animal Medical Center. Publishing Professionals, n.d. Web. 23 Nov. 2012. .

GURDON, J.B., and S. FAIRMAN. "Muscle Gene Activation by Induction and the Nonrequirement for Cell Division." Development - Dev.biologists.org. The Company of Biologists Limited, 1986. Web. 23 Nov. 2012. .

1997). The basis of all plants' alternating generations and complex life cycles could be found in a common ancestor shared with fern species, even though ferns are no better reproducing sexually than moss are fully dependent on a saturated enough environment to perform a task that flowers have developed innumerable methods of getting done (Munster et al. 1997; Mehltreter et al. 2010).

Conclusion

The life cycles of moss and ferns are highly similar, with both developing from haploid cells and gametophytes that sexually reproduce to create sporophytes, which in turn asexually reproduce by producing haploid spores that start the cycle all over again. Mosses, however, are more typically found in their haploid gametophyte stage, which the sporophytes are dependent on, whereas ferns are most often seen in the sporophyte stage, in which they can survive for hundreds of years. Both types of organisms are still being studied today to provide…

References

Capon, B, (2005). Botany for gardeners. Portland, or: Timbers.

Cavendish, M. (2000). Exploring life science Vol. 7. Tarrytown, NY: Cavendish Corp.

During, H. (1979). "Life strategies of Bryophytes." Lindbergia 5, pp. 2-18.

Evans, a. (1964). "Ameiotic Alternation of Generations: A New Life Cycle in the Ferns." Science 17(143), pp. 261-3.

The blood with the IgG must be effectively removed from the body, or reduced to levels that will not allow the cells to be a danger to the infant. If caught early enough, plasma transfers for the mother can result in enough of a reduction of IgG levels to forestall the effects to the fetus.

8)

Autoimmune diseases occur when, for a variety of reasons, the body responds to its own cells as though they were dangerous foreign cells. In this way they are similar to an allergic response; an unrecognized but harmless entity is viciously attacked by the body in an attempt to destroy the perceived intruder. This is annoying (and possibly deadly) when it comes to allergies, and far more so when the body essentially becomes allergic to itself.

Though the reasons behind the onset of Type I diabetes are still not fully understood, the disease occurs when…

Going back further, the same religious principals also inspired opposition to organ transplants and blood transfusions; before that, the Catholic Church strictly forbade any forensic scientific research, necessitating the need to dissect cadavers for medical education entirely in secret (Levine, 2008).

Just as the news media are partially at fault today for their failure to distinguish legitimate concerns from ludicrous fears in connection with the ongoing political debate over American healthcare, they are equally responsible for allowing unfounded fears of "human cloning" in connection with the beneficial uses of stem cell science. Specifically, the main source of secular opposition to stem cell research is attributable to unnecessary fears of rampant misuse of human cloning technology to clone human beings. While human cloning is hypothetically possible, no responsible scientific researcher would ever misuse current biomedical technology in that fashion. The complexities of cloning entire organisms have been well documented in animal…

References

Dershowitz, a. (2002). Shouting Fire: Civil Liberties in a Turbulent Age. Boston: Little

Brown & Co.

Friedrich, M. "Researchers Make the Case for Human Embryonic Stem Cell Research"

The Journal of the American Medical Association, Vol. 292(7); August 18, 2004:

These proteins include homologous members of yeast. The presences of these proteins suggest that E. histolytica is skilled to perform homologous recombination, which is the same as in other organisms. DNA damage was evaluated by TUNEL assay. In yeast and in human cells, histone H2AX becomes rapidly phosphorylated when DSs are introduced into chromatin (Lavi et al.).

Studies show that histone as a protein plays a significant role in the transition between the expression of a fetal gene and that of the adult gene. The adult gene's metabolism becomes oxidative in order to adapt to air and to weight, as it generates methylated transmitters and creatine phosphate. The muscles get used to life on the ground as compared to the fetal life which takes place in an aquatic environment. Regulated proteins allow the muscles to respond in a more adequate manner to this environment.

Now, let us see how histone…

Bibliography

Abraham, R.T. (2001). "Cell cycle checkpoint signaling through the ATM and ATR kinases." Genes Dev 15(17): 2177-96.

Alexiadis, V., T. Waldmann, J. Andersen, M. Mann, R. Knippers and C. CGruss (2000). "The protein encoded by the proto-oncogene DEK changes the topology of chromatin and reduces the efficiency of DNA replication in a chromatin-specific manner." Genes Dev 14(11): 1308-12.

Aten, R. And H. Behrman (1989). Antigonadotropic effects of bovine ovarian gonadotropin-releasing hormone-binding inhibitor from bovine ovaries. Purification and identification of histone H2A. J. Biol. Chem. 264: 11065-11071.

Antigonadotropic effects of bovine ovarian gonadotropin-releasing hormone-binding inhibitor/histone H2A in rat luteal and granulosal cells. J. Biol. Chem. 264: 11072-11075.

S. Congress that the prospects of stem cell research were so vast that it could touch all the realm of medicine (Connor 2000). An unlimited source of embryonic stem cells will solve the problem of shortage of transplants. Embryonic stem cells will save lives by curing generative diseases of the brain, hepatitis, diabetes, leukemia, rheumatoid arthritis, muscular dystrophy and cystic fibrosis and diseases of the heart and kidneys. ut current laws restrict the use of stems cells on embryos less than 14 days old and for correcting fertility, reproduction or congenital disorders. The restriction is grounded in the belief that the embryo is a potential human being from the moment of conception. It thus possesses a soul and a dignity just like any other viable person (Connor). Previous scientific research presented evidence that genetically engineering cells could partly repair a defective immune system (Travis 2002). Two new studies bolstered this…

Bibliography

Bauer, D.G. (2005). Review of the endocrine system. MedSurg Nursing: Jannetti Publications, Inc.

Connor, S. (2000). Science: the miracle cure with a catch. The London Independent: Newspaper Publishing PLC

Degen. D (2008). Body organization and homeostasis. 1 page. Bones, Muscles and Skin. Pearson Education, Inc.: Pearson Prentice Hall

Farabee, M.J. (2006). Animal organ systems and homeostasis. 18 web pages. Estrella Mountain Community College. Retrieved on February 1, 2006 at http://www.emc.maricopa.edu/faculty/farabee/biobk/BioBookMUSSKEL.html

Timing and Principle Characteristics of Developing Female and Male Germ Cells From Differentiation in Early Embryo to Point of Fertilization

Principle Characteristics Male and Female Germ Cells

The female and male germ cells are reproductive cells that fuse with one another during fertilization (Encarta, 2005; Burfoot, 1999). Each possesses unique characteristics and molecular structure during the prefertilization phase of development and post fertilization. These characteristics are influenced by the production of various hormones in the male and female body.

Fertilization occurs when the materials from two gametes come together to form an embryo. The female gamete is often referred to as the egg or female germ cell whereas the male gamete is often referred to as sperm or the male germ cells (Encarta, 2005; Burfoot, 1999). Developing female germ cells are generally large and contain nutrient reserves including what is referred to as the egg 'yolk' or sometimes white and…

References:

AUA. (2005). "Management of male infertility." American Urology Association,

Available:  http://www.urologyhealth.org/adult/index.cfm?cat=11& ; topic=129

Burfoot, Annette. (1999). Encycolopedia of Reproductive Technologies. Boulder:

Westview Press.

Actions Estrogen and Progesterone in Endometrium and Breast: Puberty, Pregnancy and Puerperium Including Molecular Actions and Functionally Important Tissue Level Effects

Estrogen and progesterone are essential to cyclical changes that occur during puberty, pregnancy and peurperium. Complex molecular activity influences tissue changes in multiple reproductive organs including the uterus, endometrium, ovaries, breasts and more (Kimbrell & McDonnell, 2003).During a woman's reproductive cycle the hypothalamus secretes gonadotropin-releasing hormone or luteinizing releasing hormone which stimulates the release of luteneizing hormone and follicle stimulating hormone (Merck, 2005). This in turns promotes maturation of female ovum and stimulates the body's release of the reproductive hormones estrogen and progesterone during a woman's cycle. Estrogen and progesterone contain carbon atoms and other polycyclic compounds that are created from cholesterol and circulate within the bloodstream via plasma proteins (Merck, 2005).

Unbound estrogen and progesterone compounds stimulate the reproductive system including the endometrium, uterus and breasts to mature…

References:

"Hormones of the Reproductive System of Females." Available:

http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/S/SexHormones.html

Kimbrell, E.A. & McDonnell, D.P. (2003). "Function and mode of action of nuclear receptors: Estrogen, progesterone and vitamin D" Pure Appl Chem, 75(11-12): 1671. Available:  http://www.iupac.org/publications/pac/2003/pdf/7511x1671.pdf 

Merck & Co., Inc. (2005). Reproductive Endocrinology. The Merck Manual, Sec. 18, Ch.

Alternation of Generations

Alteration of Generations

"Alternation of Generations" is a term used to explain the life cycle and pattern of reproduction in certain vascular plants, protists and fungi. Usually generations of a species take one complete life cycle; therefore, in order to avoid confusion, this term is usually replaced with the term "Alternation of Phases of a single generation."

In "Alternation of Generations," the process of reproduction is different from other reproductions; it keeps moving back and forth from a sexual from of reproduction in one generation to an asexual form of reproduction in the other generation (Polunin, 1960). Each phase of the life cycle of organisms possessing "Alternation of Generations" contains one or two independent living organism gametophyte and a sporophyte. Sporophyte and gametophyte come from the concepts: spore bearing stage (sporophyte) and gamete bearing stage (gametophyte). Genetically, a gametophyte (which can be a tissue or plant) is…

References

Fried, G and Hademenos, G. (1999). Schaum's Outline of Problems of Theory and Biology. Second Edition. The McGraw-Hill Companies. Retrieved July 11, 2012  http://books.google.com.sa/books?id=_XZtGXJIQA4C&printsec=frontcover&dq=Schaum%E2%80%99s+Outline+of+Problems+of+Theory+and+Biology&hl=en&sa=X&ei=IQr9T6b2IOOx0QXE0cihBw&ved=0CDEQ6AEwAA#v=onepage&q=Schaum%E2%80%99s%20Outline%20of%20Problems%20of%20Theory%20and%20Biology&f=false 

Niklas, K. (1999, May). Microscopic Mating Game. Natural History, 108, 44. Retrieved July 11, 2012, from Questia

database:  http://www.questia.com/PM.qst?a=o&d=5035650896 

Polunin, N. (1960). Introduction to Plant Geography and Some Related Sciences. London: Longmans. Retrieved July 11, 2012, from Questia database:  http://www.questia.com/PM.qst?a=o&d=77755670

Prokaryotic & Eukaryotic Cells

Cells can be divided into two categories: prokaryotic and eukaryotic cells. Prokaryotic cells are significantly smaller than eukaryotic cells. This size difference is due to the many contents inside a eukaryotic cell that prokaryotic cells do not have. To begin with, prokaryotic cells are always going to be unicellular, while eukaryotic cells can also be unicellular but are many times multicellular (Murray & Baron, 2007). Prokaryotic cells do not have any membrane-bound organelles inside them, such as the nucleus, mitochondria, or lysosome as eukaryotic cells do. The DNA of eukaryotic cells is linear and is contained within the nucleus, while DNA in prokaryotic cells is circular and is contained within the nuclear body, a non-membrane surrounded structure (Murray & Baron, 2007). The number of ribosomes inside a prokaryotic cell is a lot less than those contained in a eukaryotic cell. Prokaryotic ribosomes are about 70s while…

References:

Murray, Patrick R., and Ellen Jo. Baron. Manual of Clinical Microbiology. Vol. 1. Washington, D.C.: ASM, 2007. Print.

Nester, E., Anderson, D., & Roberts, C.E. (2012).Microbiology: A human perspective. (7th ed). New York, New York: McGraw-Hill Higher Education.

Gene Technology

Genetically Modified Crop Plants

The term genetically modified organisms, popularly referred to as GMOs, constitute crops, animals and even microorganisms that have undergone development my man and technology. Through the great leaps man has developed in technology, it is now possible to 'create' organisms and plants through the combination of genes considered superior, resistant and quick-maturing. Farming and animal rearing land brings a challenge in the current world, due to population explosions. This trend has been brought about by the necessity to feed the ever-increasing food demand by world populations.

The world today carries over six billion people, a number that increases every day. The natural means of plant reproduction cannot support to feed this population due to the long time taken to grow to maturity, poor yields and the limited space for planting. Therefore, genetic modification has gained an edge in the development of such crops as…

References

Conway, G. 2000. Genetically modified crops: risks and promise. Conservation Ecology 4(1): 2. [online] URL:  http://www.consecol.org/vol4/iss1/art2 

McMichael, D. Costanza, R., H. Daly, C. Folke, P. Hawken, C.S. Holling, A.J. Pimentel, and D. Rapport. (2000). Managing our environmental portfolio. Bioscience 50: 149-155.

Deborah B. Whitman (2000) Genetically Modified Foods: Harmful or Helpful? (Released April 2000)  http://www.csa.com/discoveryguides/gmfood/overview.php 

Ellstrand, N. 2000. The elephant that is biotechnology: Comments on "Genetically modified crops: risks and promise" by Gordon Conway. Conservation Ecology 4(1):8. [online] URL:  http://www.consecol.org/vol4/iss1/art8

Diversity and Organisms

Phylogeny is the patterns of lineage branching, produced by the true evolutionary history of the organisms being considered (UCMP Web site). Speciation is the changes in related organisms to the point where they are different enough to be considered separate species. This occurs when populations of one species are separated and adapt to their new physiological, geographic, or behavioral environment (Evolution Library Web site).

Plants have a reproductive cycle, which has an "alternation" between a haploid (n=one copy of each chromosome) gametophyte generation and a diploid (2n=two copies of each chromosome) sporophyte generation. The haploid gametophyte produces haploid gametes, which fuse to form a diploid zygote. The zygote grows by mitosis into the diploid multicellular sporophyte, in which meiosis occurs in special regions creating haploid spores. The spores disperse, germinate into haploid gametophytes starting the cycle anew (Kennesaw Web site).

As plants have evolved, the sporophyte has…

Bibliography

Alternation of Generations." Kennesaw Web site. URL:

http://science.kennesaw.edu/biophys/biodiversity/plants/plaltgen2.htm

The Animal Kingdom." Chapters 20 & 21. The South Dakota State University Web site. URL: http://biomicro.sdstate.edu/Hutchesh/bio101/Text/Chapt20.htm

Determinate and Indeterminate cleavage." UTM Web site. URL: