Counting Electric Eels: teacher key

Electric Eels, grade 7 edition, written for 7th grade. For about 250 years scientists counted one kind of electric eel. Now they know of at least three, and each one breathes air and hunts with pulses.

Read the book. Print this page for the key.

Questions and answers

1. For about how long did scientists count only one kind of electric eel?
   • About 25 years
   • About 250 years (answer)
   • About 2,500 years
2. What inspired the design of the first battery, in 1799?
   • Electric eels (answer)
   • A kite
   • A mountain
3. What do two quick pulses called a doublet do?
   • Make hidden fish twitch (answer)
   • Put the eel to sleep
   • Lift the eel out of water
4. An eel must come to the surface at least every ten minutes. What does that tell you?
   • It cannot live without air (answer)
   • It sleeps on land
   • It has no gills
5. What does an eel at rest give off?
   • Very little electricity (answer)
   • A great deal of electricity
   • Light
6. How often must an eel come to the surface for a breath?
   • At least every ten minutes (answer)
   • Once a year
   • Never

Words

• species: kind of animal
• doublet: two quick pulses
• suction: pulling force
• electrocytes: power cells
• poraque: Brazilian name