Embryo research Essay Example | Topics and Well Written Essays - 500 words

Embryo research - Essay Example (Singer) Hwang and his colleagues states that they exchanged the nucleus of unfertilized egg of a human for the nucleus of an ordinary cell, taken from another human, and created the lines made of stem cells from an embryo that appeared as the result. These stem cells coincidedwith the DNA of the man who provided an ordinary cell. This experiment demonstrated that it is now possible to give a cell or a tissue to a person, and they will not be rejected by the organism, having been cloned from them. (Singer) The experiments of Hwang haven't been completed. However, he assumed that definite problems might occur. He insisted on the legitimacy of his work, confessing that there may be errors in the lines of stem cells. He also confessed that few cells could be damaged. At any rate, the scientists consider this be one of the most significant discoveries in medicine and biology. Of course, experiments and researches are needed, but the results will significantly change the whole medical practice. (Robertson) But ethical background of this invention is discussed by many scientists. It shows that the potential of human life is included into each cell of our organism, and this would change the discussion about the value of a human life.

Literature review topic Coursework Example | Topics and Well Written Essays - 500 words

Literature review topic - Coursework Example The ear of fish was according to its water environment, and that of lizard is according to aerial environment. (Fay, 2008). Heart is main organ of supplying blood to all the body organs. The position of heart is also different in different genus as well as the number of chambers. Amphioxus did not contain a true heart, but there were only blood vessels in different body parts that were divided to circulate blood in their specified organs. As the evolution went on, the animals started to grow a well-developed and distinct organ that has divisions. These chambers are atria and ventricle in mammals (Marcos S. Simà µes-Costaa, 2005). Even the atria and ventricles are divided as right atrium, left atrium, right ventricle and left ventricle. These chambers do not allow any mixing of blood and there is a very less chance that oxygenated blood can get mixed with deoxygenated blood. The heart of amphioxus(genius: Branchiostoma) was not well shaped but it is now a very regular organ in mammals like horse(genus : Equus). (Josà © Xavier-Neto, 2010). Prokaryotes are single celled organisms that do not have cellular organelles. They are simple in composition while eukaryotic are complex in nature. They comprise bacteria cells. For movement, they have flagella or cilia. Although they are living, but they do not have well developed systems and specialized organs. They have simple mode of living. Their circulatory, respiratory, etc. all systems are simplest of all organisms. With the evolutionary process, they have been changed to eukaryotes, the most developed organisms of the world. The eukaryotic organisms are very much advance and they have organelles specialized for specific functions. They contain chloroplast, ribosome, mitochondria and many other special structures that are specified to do special works. Chloroplast is used in the process of photosynthesis. Mitochondrion is the