What the Genomes Show: teacher key

American Alligators, grade 12 edition, written for 12th grade and up. Read about alligator genomes, how touch and bite studies work, why survey counts are hard to compare, and how an alligator's life begins in the nest.

Read the book. Print this page for the key.

Questions and answers

1. What did genomes show about alligators in the Pleistocene epoch?
   • They grew wings
   • They declined in number (answer)
   • They left North America
2. Where do the most heavily wired sensory spots sit?
   • In the mouth near the teeth (answer)
   • On the tail
   • On the feet
3. In Everglades surveys, what happened as water got deeper?
   • Detection rose
   • Nothing changed
   • Detection fell (answer)
4. Why are alligator surveys generally not comparable from place to place?
   • Alligators look alike
   • Effort and methods differ (answer)
   • Every place has the same counts
5. What does epoch mean here?
   • A span of time (answer)
   • A kind of survey
   • A tooth
6. What can bite-force values from captive alligators be used for?
   • Counting nests
   • Sensing water ripples
   • Modeling wild alligators when matched to body mass (answer)

Words

• genomes: full gene sets
• epoch: span of time
• hertz: vibrations per second
• invertebrates: animals without backbones
• fractured: cracked or broken