In your body<span>, the excretory system helps to keep salts and urea from building up to dangerous levels and becoming toxic. The kidneys are two bean-shaped organs that </span>remove these<span>toxins from your blood and produce urine to carry them from the </span>body.<span> </span>Waste<span> products must be </span>removed from the body<span>. If they are not, they will increase in concentration and may interfere with chemical reactions or damage cells. </span>Waste<span> products that must be </span>removed<span> include carbon dioxide and urea.</span>
<span> Embryonic stem cell research is kind of a dead area now since there is no way to control the differentiation. Most research is being done on adult stem cells to help map and control the differentiation process.
Stem-cells from aborted fetuses - The government doesn't sponsor this, if it is done it is by private companies not located in the USA. You could try researching umbilical cord stem cells to be somewhere near your topic. They come from the afterbirth of normal deliveries.
You could do a much easier report by covering cloning of mice through stem-cell technology. It is happening and helping scientists understand diseases. </span>
<span>A) enzymes. Enzymes are what break down proteins. </span>
