1. Stem cells

2. What are stem cells ?
Stem cells are a class of undifferentiated cells that are able to differentiate into specialized cell types. Commonly, stem cells come from two main sources:
Embryonic Stem Cells - Embryos formed during the blastocyst phase of embryological development
Adult Stem Cells - Adult tissue
Both types are generally characterized by their potency, or potential to differentiate into different cell types, such as skin, muscle, bone, etc.

3. The history of stem cells
Stem cells have an interesting history that has been somewhat tainted with debate and controversy. In the mid 1800s it was discovered that cells were basically the building blocks of life and that some cells had the ability to produce other cells.
Attempts were made to fertilize mammalian eggs outside of the human body and in the early 1900s, it was discovered that some cells had the ability to generate blood cells.
In 1968, the first bone marrow transplant( containing stem cells) was performed to successfully treat two siblings with severe combined immunodeficiency

4. Other key events in stem cell research include
1978: Stem cells were discovered in human imbilical cord blood
1981: First in vitro stem cell line developed from mice
1988: Embryonic stem cell lines created from a hamster
1995: First embryonic stem cell line derived from a primate
1997: Cloned lamb from stem cells
1997: Leukemia origin found as haematopoietic stem cell, indicating possible proof of cancer stem cells

5. How are stem cells used
Stem cells are used in many different ways and can help treat many different diseases, I am going tell you about leukemia.
They use a Bone Marrow Transplant to Cure Leukemia. A bone marrow transplant is a procedure to replace damaged or destroyed bone marrow with healthy bone marrow stem cells. Bone marrow is the soft, fatty tissue inside your bones. The bone marrow produces blood cells. Stem cells are immature cells in the bone marrow that give rise to all of your different blood cells. A stem cell transplant is usually done after chemotherapy and radiation is complete. The stem cells are delivered into your bloodstream usually through a tube called a central venous catheter. The process is similar to getting a blood transfusion. The stem cells travel through the blood into the bone marrow. Most times, no surgery is needed.

6. Different types of stem cells
1.Embryonic Stem Cells
2.Tissue Stem Cells

7. Embryonic Stem Cells
Embryonic stem cells are stem cells derived from the undifferentiated inner mass cells of a human embryo. Embryonic stem cells are pluripotent meaning they are able to grow into all derivatives of the three primary germ layers
In simpler terms they can develop into each of the more than 200cell types of the adult body as long as they are specified to do so.

8. Tissue Stem Cells
Tissue-specific stem cells (also referred to as somatic or adult stem cells) are more specialized than embryonic stem cells. Typically, these stem cells can generate different cell types for the specific tissue or organ in which they live.
For example, blood-forming (or hematopoietic) stem cells in the bone marrow can give rise to red blood cells, white blood cells and platelets. However, blood-forming stem cells don’t generate liver or lung or brain cells, and stem cells in other tissues and organs don’t generate red or white blood cells or platelets.

9. What are the pros and cons of stem cells
Heart Diseases, Stroke and Diabetes (Type 1)
Birth Defects
Spinal Cord Injuries
Replace or Repair Damaged Organs
Reduced Risk of Transplantation (You could possibly get a copy of your own heart in a heart- transplantation in the future
Stem cells may play a major role in cancer

10. What are the pros and cons of stem cells
•"We should not mess with human life."
•"Humans should not be trying to play God

11. My resources https://explorable.com/stem-cell-pros-and-cons
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