Friday, April 20, 2007

geNEtic enGiNeeriNG+++++++

Genetic engineering, Recombinant DNA Technology, genetic modification (GM) and gene splicing are terms for the process of manipulating genes, generally implying that the process is outside the organism's natural reproductive process. It involves the isolation, manipulation and reintroduction of DNA into cells or model organisms, usually to express a protein. The aim is to introduce new characteristics or attributes physiologically or physically, such as making a crop resistant to herbicide, introducing a novel trait, or producing a new protein or enzyme, along with altering the organism to produce more of certain traits. Examples can include the production of human insulin through the use of modified bacteria, the production of erythropoietin in Chinese Hamster Ovary cells, and the production of new types of experimental mice such as the OncoMouse (cancer mouse) for research, through genetic modification.
Since a protein is specified by a segment of DNA called a gene, future versions of that protein can be modified by changing the gene's underlying DNA. One way to do this is to isolate the piece of DNA containing the gene, precisely cut the gene out, and then reintroduce (splice) the gene into a different DNA segment.
Daniel Nathans and Hamilton Smith received the 1978 Nobel Prize in physiology or medicine for their isolation of restriction endonucleases, which are able to cut DNA at specific sites. Together with ligase, which can join fragments of DNA together, restriction enzymes formed the initial basis of recombinant DNA technology.
Some groups have argued
[citation needed] genetic engineering is wrong and is "doing the work of God", but most scientists believe that genetic engineering is essential to help future medical discoveries.

bisexuality v.s. homosexuality

Bisexuality is a sexual orientation which refers to the aesthetic, romantic, and/or sexual attraction of individuals to other individuals of either their own or the opposite gender or sex. Most bisexuals are not equally attracted to men and women, and may even shift between states of finding either sex exclusively attractive over the course of time.[1] However, some bisexuals are and remain fairly static in their level of attraction throughout their adult life.
In the mid-1950s,
Alfred Kinsey devised the Kinsey scale in an attempt to measure sexual orientation. The 7 point scale has a rating of 0 ("exclusively heterosexual") to 6 ("exclusively homosexual"). Bisexuals cover most of the scales' values (1-5) which ranges between "predominantly heterosexual, only incidentally homosexual" (1) to "predominantly homosexual, only incidentally heterosexual" (5). In the middle of the scale (3) is "equally heterosexual and homosexual".[1]
Although observed in a variety of forms in human societies and in the animal kingdom throughout recorded history[citation needed], the term "bisexuality" (like the terms "hetero-" and "homosexuality") was only coined in the 19th century.[2]

Bisexual people are not necessarily attracted equally to both genders. [1]. Due to the nature of bisexuality as an often ambiguous position between homosexuality and heterosexuality, those who identify, or are identified, as bisexuals form a heterogenous group.
Some view that bisexuality is a distinct
sexual orientation on a par with heterosexuality or homosexuality.[3] This views bisexuality as something clearly distinct from these other two sexualities, with a clear attraction to both men and women required.
Others view bisexuality as more ambiguous. Some people who might be classified by others as bisexual on the basis of their sexual behavior self-identify primarily as
homosexual. Equally, otherwise heterosexual people who engage in occasional homosexual behaviour could be considered bisexual, but may not identify as such. For some who believe that sexuality is a distinctly defined aspect of the character, this ambiguity is problematic. It is sometimes argued that the behaviour of bisexuals may be explained by a subconscious homophobia or peer pressure.[citation needed] On the other hand, some believe that the majority of people contain aspects of homosexuality and heterosexuality, but that the intensities of these can vary from person to person.[citation needed] Some people who engage in bisexual behavior may be supportive of lesbian and gay people, but still self-identify as straight; others may consider any labels irrelevant to their positions and situations.
Some bisexuals make a distinction between
gender and sex. Gender is defined in these situations as social or psychological category, characterised by the normal practices of men and women. For example, the fact that women wear dresses in Western Society whilst men traditionally do not is a gender issue. Sex is defined as the biological difference between males and females, prior to any social conditioning. Bisexuals in this sense may be attracted to more than one gender but only to one sex. For example, a male bisexual may be attracted to aspects of men and masculinity, but not to the male body. Such a person's attractions may manifest themselves through sexual activities other than anal sex with other males.

Bisexuality is often misunderstood as a form of adultery or polyamory, and a popular misconception is that bisexuals must always be in relationships with men and women simultaneously. Rather, individuals attracted to both males and females, like people of any other orientation, may live a variety of sexual lifestyles. These include: lifelong monogamy, serial monogamy, polyamory, polyfidelity, casual sexual activity with individual partners, casual group sex, and celibacy. For those with more than one sexual partner, these may or may not all be of the same gender.