Proof, Step by Step: teacher key

Germs, grade 11 edition, written for 11th grade. From a cloth merchant's lenses to two Vienna hospital clinics, follow how people learned what germs do and how handwashing was tested, then read the dated numbers on drug-resistant infections.

Read the book. Print this page for the key.

Questions and answers

1. How did patients end up in the two Vienna clinics?
   • They chose the one they liked
   • They went on alternate days (answer)
   • Doctors picked the sickest for one clinic
2. How many births were counted from 1840 to 1846?
   • 42,795 (answer)
   • 12,700
   • 98,400
3. Why does the alternate-day schedule make the comparison strong?
   • It let doctors choose patients
   • It removed all germs
   • It acted like a controlled trial without anyone planning it (answer)
4. Why could Semmelweis not explain why handwashing worked?
   • He did not wash his own hands
   • No one knew about germs in 1847 (answer)
   • The clinics closed
5. In this passage, what does a postulate do?
   • Counts births
   • Kills bacteria
   • Gives a rule to test an idea (answer)

Words

• postulates: required criteria
• controlled: carefully compared
• antisepsis: germ prevention
• phagocytosis: cell swallowing germs
• resistance: drug immunity