What Are Stem Cells?

Watch the video clip “A Stem Cell Story”.

List 3 uses of stem cells in medicine.

Follow along with the Power Point and fill in the information needed below: Stem cells are different from other cells of the body because stem

cells can both:

1) _________________________: Make copies of themselves

AND

2) _________________________: Make other types of cells –

specialized cells of the body.

Ex.

Specialized cells cannot divide to make copies of themselves. This makes stem cells very important. The body needs stem cells to replace specialized cells that die, are damaged or get used up. Why differentiate? Why self-renew? There are 3 types of stem cells:

1) __________________________________

We all have stem cells in our bodies all the time. They replace cells that are damaged or used up. They are more limited than embryonic stem cells. Tissue stem cells can ONLY make the kinds of cell found in the tissue they belong to.

So, blood stem cells can only make the different kinds of cell found in the blood. Brain stem cells can only make different types of brain cell. And so forth. They can make multiple types of specialized cell, but NOT all the kinds of cell in your body. Therefore, are called: ____________________________

2) ___________________________________ Are taken from inside the blastocyst, a very early stage embryo (a ball of about 50-100 cells not yet implanted in the womb). ES cells are found in the inner cell mass.

Embryonic stem cells are exciting because they can make all the different types of cell in the body – scientists say these cells are: __________________________

Why might the use of embryonic stem cells in research be considered controversial? (think-pair-share)

3) ___________________________________ These stem cells are made in a lab. Scientists add particular genes to cells from the body to make them behave like embryonic stem cells. This process is a bit like changing the instructions in a computer program to make the computer do a new task. Scientists call the process they use to make iPS cells ‘genetic reprogramming’.

What is the advantage of using iPS cells over ES cells?

Watch the video clip and answer the questions below: Dr. Yamanaka won a Nobel Prize for his discovery that mature, specialized cells can be reprogrammed

to become pluripotent. What is one risk he found with using his technique? Brainstorm how scientists could try to solve this problem.