Hiccups, Sneezes, Yawns: The Open Questions: teacher key

Hiccups, Sneezes and Yawns, grade 9 edition, written for 9th grade. Scientists can describe a hiccup, a sneeze and a yawn, but each still has puzzles. See the theories about why we yawn, what is unknown about hiccups, and what is still being tested.

Read the book. Print this page for the key.

Questions and answers

1. What do we know about why we hiccup?
   • Hiccups clear the lungs of dust
   • Hiccups have no obvious purpose (answer)
   • Hiccups wake up the brain
2. What did studies find about the idea that yawning brings in more oxygen?
   • They did not support it (answer)
   • They proved it true
   • They never tested it
3. Why do researchers doubt the oxygen idea?
   • Adults yawn too rarely
   • Yawns last too long
   • A fetus gets oxygen through the cord yet still yawns (answer)
4. What does the communication theory say a yawn may do?
   • Pull in cool air
   • Tell people around you that you are bored or stressed (answer)
   • Wake up the legs
5. How sure are scientists about how light makes people sneeze?
   • Not sure (answer)
   • Completely sure
   • It has been ruled out
6. What does empathy mean?
   • Being very tired
   • Breathing deeply
   • Understanding and sharing another's feelings (answer)

Words

• reflex: automatic body action
• theory: possible explanation
• oxygen: breathing gas
• empathy: sharing feelings
• photic: about light