One germ grips the lung lining and its cousin grips the gut. Which diseases result?

• The same disease from both, since sticking changes nothing
• Breathing illness from the lung gripper and diarrhoea from the gut gripper
• Diarrhoea from both, since the two germs are cousins

Which order do the four gates of infection run in?

• Reach a surface, stick, push past defences, secure iron
• Secure iron, stick, reach, push past defences
• Reach a surface, secure iron, stick, push past defences

Which toolkit item steals iron for the germ?

• Enzymes that dissolve tissue barriers
• Capsules that shield germs from phagocytes
• Siderophores that steal iron from the host

A mutant grows normally in a dish yet causes far weaker disease. What does that gap tell you?

• The deleted gene is a true virulence factor
• The deleted gene only controls growth speed
• The test failed, since growth and disease always match

A pathogen loses its adhesion gene but still grows in a dish. What happens at its usual site?

• It infects as usual, since growth in a dish is normal
• It fails to grip and infect its usual site
• It switches to a new tissue entirely on its own

You want the cheapest place to stop an infection. Where do you block it?

• At the toxins, after the germ has settled in
• At feeding, by adding extra iron for the germ
• At sticking, since every later gate needs the grip

A gene that slows growth in a dish but leaves disease unchanged marks a true virulence factor.

A new strain tests positive for gripping lung tissue. A friend claims it will cause diarrhoea. What is wrong with that claim?

• Nothing is wrong; tissue grip cannot predict disease
• New strains never follow the sticking rule
• Lung grippers cause breathing illness, so diarrhoea needs gut grippers