Medical Issues- Stem Cells
Click on The Nature of Stem Cells to answer the following questions. 1.) Compare a stem cell and a specialized cell.
Specialized cells carry out specific functions. These specialized cells are called differentiated cells. On the other hand, a stem cell is undifferentiated. Its role in the body is not yet determined. A stem cell can give rise to multiple cell types, including many stem cells.
2.) Describe a blastocyst.
The blastocyst looks like a lopsided hollow ball. The cells around the outside of the ball will form the placenta. A clump of cells on the inside will form all the cells of the body.
3.) Two weeks after fertilization the cells organize into how many layers? 3 layers What triggers this organization?
Cells signals restrict the potential of these cells even further. Each layer will give rise to a different set of cell types.
4.) Describe what each layer forms-
Ectoderm- skin, nervous system, and parts of the face and neck
Mesoderm- muscle, blood, blood vessel, and the beginning of bones and connective tissue
Endoderm- digestive and respiratory tracts and the glands that feed into them, including the pancreas and the liver
5.) Another name for adult stem cells is Somatic.
Describe their function.
Somatic cells play an important role in growth, maintenance, and repair.
6.) Compare embryonic and somatic stem cells.
Somatic stem cells differ from embryonic stem cells: under natural conditions, they can give rise to just a few cell types.
7.) Besides bone marrow where are the somatic stem cells found?
Somatic stem cells have been found in many other tissues, including brain, blood, blood vessels, muscle, skin, teeth, heart, gut, and liver.
Click on Reversing Cell Differentiation to answer the following questions. 1.) Describe what scientists were able to do in 2006.
In 2006, scientists reported that they had turned a differentiated cell back into a stem cell with the potential to become any type of cell in the body.
2.) As differentiation begins what happens to the genes that will not be needed for that particular cell type?
As differentiation begins, genes that will not be needed are shut down.
3.) Describe Histones.
Histones are proteins that DNA is wrapped around loosely.
4.) The final number of genes that Japanese scientists introduced to convert a differentiated cell into stem cells is four. Explain how these genes accomplish this.
The genes appear to be remodeling the cells’ DNA, unlocking the genes that were shut down during differentiation.
Click on Go Go Stem Cells to answer the following questions.
Blood Cell Niche
1.) Describe the shape of the red blood cells (RBCs).
Red blood cells are shaped like a disc with a dent in the middle.
2.) Where is the stem cell niche responsible for producing blood cells?
The stem cell niche is responsible for producing blood cells is inside the bones, in the bone marrow.
3.) Describe hemoglobin.
Hemoglobin is a protein that carries oxygen to tissues in the body. Each red blood cell contains about 270 million hemoglobin molecules.
4.) What is lost as the transformation from stem cell to blood cell occurs?
As transformation from stem cells to blood cells occurs, the nucleus and most of the other organelles are lost.
5.) Describe the function of each of the following:
Red Blood Cells- transport oxygen from the lungs to the body tissues using a molecule called hemoglobin.
White Blood Cells- protect the body from infection and disease. All 5 kinds of white blood cells have different jobs.
Platelets- controls bleeding by causing the blood to clot to seal off wounds.
Brain Stem Cell Niche
1.) Describe the role of neurons.
Neurons send and receive signals in the brain.
2.) Which 2 brain regions contain stem cells?
The 2 brain regions that contain stem cells are called the hippocampus and the olfactory bulb.
3.) Describe the role of the...
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