Weismann‚ who noted that two cell divisions were necessary to transform one diploid cell into four haploid cells if the number of chromosomes had to be maintained. In 1911 the American geneticist Thomas Hunt Morgan observed crossover in Drosophila melanogaster meiosis and provided the first genetic evidence that genes are transmitted on chromosomes. The term meiosis was introduced to biology by J.B. Farmer and J.E.S. Moore in 1905 Meiosis i/maɪˈoʊsɨs/ is a special type of cell division necessary for
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multitude of skin lesions of the course of a lifetime. Some of the lesions are benign‚ easily visible‚ or just new benign growth. Therefore‚ most benign skin lesions are diagnosed on the appearance and history. However‚ if a lesion has exhibited unexpected changes in appearance‚ a biopsy or excision is indicated to confirm the diagnosis. Usually‚ benign lesions are symptomatic and can be managed with simple procedures‚ such as cryotherapy‚ electro-surgery‚ or excision. Some example of benign skin lesions
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Skin Cancer What is it and how to prevent it Skin cancer is the most prevalent of all cancers. There are three types of skin cancer: basal cell carcinoma‚ squamous cell carcinoma‚ and malignant melanoma. In this presentation I plan to discuss a little about each of these cases as well as tell ways to prevent and treat them. The first most common skin cancer is basal cell carcinoma. This cancer develops in the basal or bottom layer of the epidermis‚ which is the top layer of the skin
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For alternate meanings see skin (disambiguation) Diagram of the layers of human skinIn zootomy and dermatology‚ skin is an organ of the integumentary system composed of a layer of tissues that protect underlying muscles and organs. As the interface with the surroundings‚ it plays the most important role in protecting against pathogens. Its other main functions are insulation and temperature regulation‚ sensation and vitamin D and B synthesis. Skin has pigmentation‚ provided by melanocytes
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The Birth of the Euro and Its Effects The Birth of the Euro and Its Effects ROBERT SOLOMON Guest Scholar The Brookings Institution T he euro was born at the beginning of this year as the currency of the newly formed European Economic and Monetary Union (EMU). As has been widely observed‚ this is a historic event. Not since the Roman Empire has a good part of Europe had the same currency. EMU was conceived in 1988–89 by a committee consisting mainly of central bankers chaired by Jacque
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see when you look at a person is their skin. It’s the largest organ of the body that’s made of epithelial tissue. It consists of two main layers‚ the epidermis and the dermis. As it’s the first thing in contact with the environment around us‚ it acts as a protective layer. Skin cancer is the rapid uncontrollable growth of abnormal skin cells that’s usually triggered by ultraviolet radiation. When skin cells with damaged DNA grow rapidly they form tumors. (Skin Cancer Foundation‚ n.d.)These tumors
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Stem cells -are biological cells found in all multi cellularorganisms‚ that can divide (throughmitosis) and differentiate into diverse specialized cell types and can self-renew to produce more stem cells. In mammals‚ there are two broad types of stem cells: embryonic stem cells‚ which are isolated from the inner cell mass of blastocysts‚ and adult stem cells‚ which are found in various tissues. In adult organisms‚ stem cells and progenitor cells act as a repair system for the body‚ replenishing
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When dealing with acne skin care‚ most of the medical professionals commonly suggest that people affected with acne must practice certain acne skin care methods that will help improve the condition of their skin. Acne‚ as you may already know‚ is a very severe skin disorder that affects thousands of people from all over the world. It not only affects the surface of the skin but also the inner layers of the skin. Acne usually occurs on the face‚ neck‚ chest and back‚ and it starts during the adolescence
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Name: ______________________________________ Date: ________________________ Student Exploration: Osmosis Vocabulary: cell membrane‚ concentration‚ diffusion‚ dynamic equilibrium‚ osmosis‚ semipermeable membrane‚ solute‚ solvent Prior Knowledge Questions (Do these BEFORE using the Gizmo.) 1. Suppose you were trapped on a desert island with no sources of fresh water. Should you drink water from the ocean? Explain why or why not. _________________________________________________________________________
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An Understanding of Biracial Identity Formation for Special Topics 3321 Presented to James Boyleston by Jennifer Walne December 10‚ 2008 Abstract What are you? A question that seems simple enough‚ but when dealing with biracial identity‚ it is a question that has spawned political movements‚ fields of study‚ and even more questions. This paper is aimed at dissecting different aspects of the biracial identity process to gain a better understanding about this subject from
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