The Switch at Birth: teacher key

Belly Buttons, grade 8 edition, written for 8th grade. In the first seconds after birth, a baby's circulation changes. Follow the blood to learn what the cord did, what it left behind and why belly buttons differ.

Read the book. Print this page for the key.

Questions and answers

1. What does Wharton's jelly do?
   • It acts as a shock absorber for the vessels (answer)
   • It feeds the baby
   • It closes the stump
2. What starts the switch-off at birth?
   • The stump drying
   • The first breaths (answer)
   • The cord twisting
3. How long does ACOG advise waiting before cutting the cord for healthy babies?
   • At least 30 to 60 seconds (answer)
   • At least 30 minutes
   • No waiting at all
4. Why is the cause of an outie described as unknown?
   • Nobody has looked at belly buttons
   • Scientists only know it may depend on healing and body space (answer)
   • It is chosen at birth
5. What does the word monotremes mean?
   • Mammals with pouches
   • Mammals that lay eggs (answer)
   • Mammals without hair

Words

• umbilical: of the cord
• Wharton's: cord cushion
• placenta: baby's supply organ
• marsupial: pouch mammal
• Monotremes: egg-laying mammals