Questions for ‘A new drug mix helps frogs regrow amputated legs’

Adult African clawed frog

Adult African clawed frogs can’t fully regrow lost body parts on their own. But a new device that holds a chemical cocktail at the wound site has coaxed some frogs to regrow useful limbs.

Brian Gratwicke/Flickr (CC BY 2.0)

To accompany A new drug mix helps frogs regrow amputated legs


Before Reading:

  1. Consider how a human body changes from a newborn infant to a teenager and then an adult. Do you think the number of cells that make up that person’s body tends to increase, decrease or stay the same? Do you think the cells that make up our bones are the same or different from the cells making up our brains? Explain your answer.
  2. Every human body started out as only one single cell. That cell multiplied into many. Eventually that cell gave rise to all the parts of the human body. What does that suggest about the type of information that must be stored in that first human cell? 
  3. Bacteria reproduce by pinching themselves apart to make copies of themselves. Since they are single-celled organisms, this process works just fine. But humans are multicellular. What is the difference between a single-celled organism and a multicellular organism? (If you aren’t sure, then do a quick internet search.) Based on what you know, why do you think a colony of bacteria is not considered a multicellular organism?

During Reading:

  1. In this study, what does a newly-developed device deliver to a wound site in frogs? 
  2. According to Michael Levin, why is coaxing a frog’s body to make a new leg not “as wild as it may seem”?
  3. Into how many groups were the frog amputees split? What are “BioDomes?”
  4. After 18 months, which frog group showed the best results? Describe those results. 
  5. What animal species has Levin’s team moved on to study now? 
  6. According to Levin, what must we understand better about cells if we want to one day regenerate human tissues? 

After Reading:

  1. John Barker says, “Instead of treating symptoms, you could literally cure a disease.” What example does this article provide? Come up with a second example of how an ailment or disease might potentially be cured in this way — and explain your answer.
  2. Imagine this new limb-regrowing technology went to human trials. Why might the frog experiment set-up not be an ethical option for testing the tech in people? How might the experiment’s design be adjusted to remove that ethical challenge?