Counting the Unseen: teacher key

Germs, grade 12 edition, written for 12th grade and up. From a cloth merchant's lenses to dated estimates of drug-resistant infections, the science of germs is a record of careful measurement, revised numbers and honest open questions. Read how evidence was built and where it still runs thin.

Read the book. Print this page for the key.

Questions and answers

1. What did Pasteur's experiments support?
   • That mold makes wine
   • That germs cause disease, against miasma theory (answer)
   • That air creates life
2. What is the most common type of virus, by number?
   • Rhinoviruses
   • Cowpox viruses
   • Phages (answer)
3. Why is the usual story that Semmelweis was ignored too simple?
   • He refused to publish for years and insisted on one cause (answer)
   • He was never a doctor
   • Nobody had tried handwashing
4. Why do the estimates of resistance deaths change from report to report?
   • Bacteria stop being counted
   • They are estimates that new data revises (answer)
   • Deaths are recorded once
5. In this passage, what does the word postulates describe?
   • Types of microscopes
   • Vaccines
   • Criteria for judging a cause (answer)

Words

• microbiome: body's microbe community
• postulates: required criteria
• phages: bacteria-infecting viruses
• pasteurization: heat treatment
• antisepsis: germ prevention