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The Bionic Body


 
Teaching Guide
Nuclear Transplants
Coordinated Control
Nuclear Transplants
Uncovering a Signal
Quiz
Image of Nerve Cell

In "Born Again Nerves," scientists use stem cells to repair damaged nerves in rats. Stem cells are the "blank slate" from which all other, more specialized cells are derived. Through this proceedure these cells can be "instructed" to develop into new, much-needed nerve cells.

For several years scientists have been able to perform another proceedure that can alter cell development - placing the nucleus of one cell into the body of another. If this transfer is successful (and the original cell's nucleus is destroyed), the nuclear implant takes over control of the new cell. Under new nuclear control, the cell transforms its structure and biochemistry to meet the commands issued by the new nucleus.

Note to educators

 

MODELING A CELLULAR OPERATION

In this activity, you'll have the opportunity to model the removal of a cell nucleus and the insertion of an alternate control center. Although you won't be operating on real cells, you'll define some of the challenges faced in this type of transplant procedure.

 

OBJECTIVE
This activity page will offer:

  • a kinesthetic experience that offers understanding in nuclear transplants
  • an opportunity for students to emulate the removal and insertion of a cell organelle
  • an opportunity to practice fine motor skills

MATERIALS

  • commercial gelatin (clear)
  • hot water (heated and distributed by instructor)
  • laboratory beaker
  • stirring rod
  • plate
  • medicine dropper
  • round sugar sprinkles (used to decorate cupcakes)
  • cool water
  • ice water bath
  • graduated cylinder
  • safety goggles
  • laboratory balance

PROCEDURE

PART 1 - Modeling A Cell

  1. Add 0.5 grams of gelatin powder to a beaker.
  2. Put on your safety goggles. Your instructor will add 45 mL of hot water to the powder. Carefully mix the powder.
    CAUTION: Hot water can produce serious burns. Handle with care and follow all laboratory precautions identified by your instructor.
  3. Add 45 mL of cool water to the dissolved gelatin. Mix well and place this liquid gelatin in an ice-water bath.
  4. After about ten minutes to fifteen minutes, examine the consistency of the gelatin. You'll need to work with a soft, just setting mixture. If the gelatin is too runny, leave it in the ice-water for another 5 minutes. If its consistency is satisfactory, remove the beaker from the ice water bath.
  5. Place the gelatin mound on a plate. Slice the upper half of the gelled mass and carefully support it while scattering several sprinkles in the center. Close up the "blob". The sprinkles should be visible in the center of the loose gelatin.

PART 2 -Nuclear Transplants

  1. Squeeze out the air from a medicine dropper bulb.
  2. Poke the delivery end of the dropper into the gelatin mass.
  3. Carefully direct the opening of the dropper to the target "nucleus".
    Image of hand with a droppper
  4. When the opening is in front of the nucleus, release the pressure on the dropper bulb. What happens?
  5. Remove the dropper.
  6. Exchange gelatin masses with another student. Insert the "nucleus" you removed from your gelatin into this new sample.

QUESTIONS

  1. What did the gelatin represent?
  2. What did the round sprinkle represent?
  3. Why did the bulb of the dropper need to be depressed as the dropper was introduced into the gelatin?

CONTROVERISAL RESEARCH
As you might image, it's possible to insert the nucleus from one animal into the cell body taken from another animal. This technique forms the basis of cloning. When an animal is cloned, the nucleus from one of its cells is inserted into the cell body of another cell. The transplanted control center takes over the new cell body and produces a cell with the properties of the transplanted nucleus. As the cell divides, its daughter cells assume the same transplanted properties. The organism that arises from these divisions is a clone of the animal from which the original nucleus was taken. This type of research has the potential to produce all sorts of cloned organs that can replace damaged human structures. Some people, believe that this type of research is not moral and shouldn't be conducted. What do you think? What are the advantages and disadvantages of cloning? What common ideas about cloning are misconceptions based upon science fiction stories? What are the real facts? Learn more about pig cloning and human transplants online.

WEB CONNECTION

An overview of nuclear transfer technology

The background, history and ethical use of stem cells


A well-illustrated site presenting an overview of the nucleus


Answers

The activities in this guide were contributed by Michael DiSpezio, a Massachusetts-based science writer and author of "Critical Thinking Puzzles" and "Awesome Experiments in Light & Sound" (Sterling Publishing Co., NY).

Academic Advisors for this Guide:

Corrine Lowen, Science Department, Wayland Public Schools, Wayland, MA
Suzanne Panico, Science Department, Fenway High School, Boston, MA
Anne E. Jones, Science Department, Wayland Middle School, Wayland, MA

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