The debate of the pros and cons of stem cell research clearly illustrate the difficult ethics evaluations researchers sometimes must do.

All scientists must consider whether the positive effects from their research are likely to be significantly higher than the negative effects.

Stem Cells are crucial to develop organisms. They are nonspecialized cells which have the potential to create other types of specific cells, such as blood-, brain-, tissue- or muscle-cells.

Stem cells are in all of our body and lives, but are far more potent in a fetus (also spelled foetus, ftus, faetus, or ftus) than in an adult body.

Some types of stem cells may be able to create all other cells in the body. Others have the potential to repair or replace damaged tissue or cells.

Embryonic Stem Cells are developed from a female egg after it is fertilized by sperm. The process takes 4-5 days.

Stem cell research is used for investigation of basic cells which develop organisms. The cells are grown in laboratories where tests are carried out to investigate fundamental properties of the cells.

There are stem cells in the both placenta and blood contained in the placenta. Also the primary source of stem cells is from blastocysts. These are fertilized human eggs that were not implanted into a woman.

The controversy surrounding stem cell research led to an intense debate about ethics. Up until the recent years, the research method mainly focused on Embryonic Stem Cells, which involves taking tissue from an aborted embryo to get proper material to study. This is typically done just days after conception or between the 5th and 9th week.

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Stem Cell Research - Pros and Cons - explorable