Essay - Human Genome, Stem Cells, & Reparations Stems Cells are the...

Human Genome, Stem Cells, & Reparations

Stems Cells are the source of all body tissues. Growth and development of the human ***** arises from the stem cell and is maintained by it. Although all cells can divide or copy themselves, ***** cells are unique because they can replicate ***** create all other types of *****. This ability ***** the stem cell to develop in***** any of the 220 cell types that make up the human body makes it a powerful tool for biological research and medic*****e. Scientists believe that ***** cell ***** has the potential ***** leading to previously incurable diseases.

***** are Stem Cells Formed?

When a sperm cell fertilizes an egg, a zygote (fertilized egg) is formed. The zygote divides *****self ********** immediately to form stem cells. *****se unspecialized stem cells have the ability ***** replicate (to form ***** ***** cells) ********** to make all other specialized cells that make up the ***** t*****sues such as bone cells, blood *****, muscle, and skin cells. Although stem ***** are present in every cell of ***** body even in an adult, they lose some of their ability to make a wider r*****nge of ********** with age. Hence, the youngest ***** cells, i.e., those found in ***** embryo are most useful for research ***** medicinal purposes.

***** of ***** Cells

***** Cells can be obtained for ***** purposes through four different methods.

***** Clinics: During fertility treatment, a process known ***** in-vitro fertilization is used in which eggs removed surgically from a female ovary ***** ***** with sperms in a lab for subsequent implant ***** a woman's uterus. Numerous fertility clinics fuse more than one egg ***** sperm as a routine—this is d***** ***** try another implant if the first one *****oes not work. There are thousands of such "left-over" embryos in liquid nitrogen freezers in ***** USA and elsewhere. These ***** are the most common source for scientific research.

Aborted Fetuses: Aborted fetuses donated by women were first ***** for developing stem cell culture by researchers ***** could be a*****her source ***** embryos.

Cloning: Privately funded research companies, e.g., Advanced Cell Technology of Worcester, M*****s., are *****ing to create cloned human embryos as sources for stem cells for commercial purposes.

Made ***** Order: Some companies ***** fertilized eggs specially to create stem cell ***** ***** research purposes. These include the Jones Institute in Virginia, USA.

Out of the 4 sources ***** "left-over" ***** ***** the in-vitro fertilization clinics ***** the ***** ethically acceptable and widely used source for ***** cell *****.

Methodology

The methodology ***** cultivating stem cell lines in the laboratory (usually in vitro fertilization *****) is briefly described below:

An egg removed surgically from a female ovary is *****jected with a sperm. A day after its fertilization, the egg spl***** into a two-*****ed embryo, which splits into 4 cells ***** ***** after and continues to split until, on the *****th or the 5th day, the ***** becomes a multi-celled b*****ll called a blastocyst. At this point the embroyo