full transcript

From the Ted Talk by Jessica Whited: How do animals regrow their limbs? And why can't humans do it?

Unscramble the Blue Letters


Most salamanders, including axolotls, develop their limbs in the same way. But unlike other animals, they can also sratt this posrces all over again if they need to. When salamanders lose a limb, surrounding skin cells quickly surge across the wound’s surface. This new layer of skin is called the wound emripdeis, and once established, it siganls cells in the underlying limb stump to uedgrno something called ddienietfeoftrain. This process reverts nearby cells from fully developed limb tseuiss back into eearilr, less specialized progenitor cells. At the same time, the peripheral nervous system fires up stem cells throughout the salamander’s body. This would be impossible for most muaelutillclr organisms, whose stem cells tylaiplcy lose their regenerative capacity with age. But when salamander stem cells near the injury get the right signal, they reactivate and start multiplying.

Open Cloze


Most salamanders, including axolotls, develop their limbs in the same way. But unlike other animals, they can also _____ this _______ all over again if they need to. When salamanders lose a limb, surrounding skin cells quickly surge across the wound’s surface. This new layer of skin is called the wound _________, and once established, it _______ cells in the underlying limb stump to _______ something called _________________. This process reverts nearby cells from fully developed limb _______ back into _______, less specialized progenitor cells. At the same time, the peripheral nervous system fires up stem cells throughout the salamander’s body. This would be impossible for most _____________ organisms, whose stem cells _________ lose their regenerative capacity with age. But when salamander stem cells near the injury get the right signal, they reactivate and start multiplying.

Solution


  1. tissues
  2. undergo
  3. typically
  4. epidermis
  5. earlier
  6. process
  7. dedifferentiation
  8. signals
  9. multicellular
  10. start

Original Text


Most salamanders, including axolotls, develop their limbs in the same way. But unlike other animals, they can also start this process all over again if they need to. When salamanders lose a limb, surrounding skin cells quickly surge across the wound’s surface. This new layer of skin is called the wound epidermis, and once established, it signals cells in the underlying limb stump to undergo something called dedifferentiation. This process reverts nearby cells from fully developed limb tissues back into earlier, less specialized progenitor cells. At the same time, the peripheral nervous system fires up stem cells throughout the salamander’s body. This would be impossible for most multicellular organisms, whose stem cells typically lose their regenerative capacity with age. But when salamander stem cells near the injury get the right signal, they reactivate and start multiplying.

Frequently Occurring Word Combinations


ngrams of length 2

collocation frequency
stem cells 5
limb buds 2
blood vessels 2
progenitor cells 2
blastema cells 2


Important Words


  1. age
  2. animals
  3. axolotls
  4. body
  5. called
  6. capacity
  7. cells
  8. dedifferentiation
  9. develop
  10. developed
  11. earlier
  12. epidermis
  13. established
  14. fires
  15. fully
  16. impossible
  17. including
  18. injury
  19. layer
  20. limb
  21. limbs
  22. lose
  23. multicellular
  24. multiplying
  25. nearby
  26. nervous
  27. organisms
  28. peripheral
  29. process
  30. progenitor
  31. quickly
  32. reactivate
  33. regenerative
  34. reverts
  35. salamander
  36. salamanders
  37. signal
  38. signals
  39. skin
  40. specialized
  41. start
  42. stem
  43. stump
  44. surface
  45. surge
  46. surrounding
  47. system
  48. time
  49. tissues
  50. typically
  51. undergo
  52. underlying
  53. wound