Research on one kind of stem cell (human embryonic stem cell) has generated much interest and public debate.
Scientific uses stem cells from human embryos, which candevelop into different kinds of adult cells, to seek cures for many medical problems. Opposition to stem cell research hinges on the question: “when does human life begin?”
To start this paper wehave to look at some definitions first to be able to perform some debate regarding the topic.
What is a stem cell? Stem cells are found in all multicellular organisms. They are characterized by theability to renew themselves through mitoticcell division and differentiating into a diverse range of specialized cell types. It is the universal beginning cell, full of potential. Steam cellsrepresent the ancestors of all specialized cells. The ultimate stem cell is the fertilized human egg, from which all the cells in the body develop.
Now let’s see. What are embryonic stem cells? Astheir name suggests, are derived from embryos. Most stem cells are derived from embryos that develop from eggs that have been fertilized (in vitro-in a clinic-); and then donated for researchpurposes. They are NOT derived from eggs fertilized in a woman’s body.
Knowing what a stem cell is and what embryonic stem cells are, it’s time to find out what is an embryo? The embryos are derived fromfour- and five-day-old embryos created through in vitro fertilization. Embryos at this stage, called blastocysts, are spheres containing about 100 cells. They have no nervous system, no heart, andno specialized tissues. Many of the cells are still undifferentiated, meaning they can become any type of cell in the human body. Therefore an embryo becomes a fetus in about eight weeks intogestation, when specific tissues and organs have started to form.
There are many ways in which human stem cells can be used in research and the clinic. Studies of human embryonic stem cells will yield...