Bacteriophages as Predators and as Laboratory Tools · seed 1 · A4, ink-friendly. The answer key prints on its own page for grown-ups.

Hunters that read surfaces

Science · Microbiology · ages 19-21
Name ______________________   Date ____________

  1. You count 30 clear zones on the lawn. How many starters landed?

    Answer: ______________

  2. What decides which bacteria a hunter virus can dock with?

    • Colour of the dish
    • Size of the colony
    • Matching surface spots

  3. A famous hunter experiment proved DNA carries the genes.

    Circle one:   True   False

  4. How do hunters act as predators in the wild?

    • They feed all strains equally
    • They prune whichever strain grows common
    • They ignore dense blooms

  5. How would you type an unknown bacterium with hunters?

    • Drip a panel of known viruses and watch which one bursts it
    • Weigh the dish
    • Smell the culture

  6. A bacterium changes its surface spot. What happens to its hunter?

    • It can no longer dock
    • It docks even better
    • Nothing changes

  7. A friend says sloppy hunters proved genes are DNA. Is that right?

    • Yes, sloppy hunters prove most
    • No, strict matching gives clean answers
    • Yes, specificity plays no role

  8. A strain turns resistant though the hunter is fine. Where is the change?

    • The hunter widens its menu
    • The dish runs out of food
    • The surface spot changed
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Answer key

For grown-ups. Fold this page away before handing over the rest.

Hunters that read surfaces W1-mt_vOnjSpXjrj-s1

  1. 30 · One starter particle carves one zone, so 30 zones means 30 starters landed.
  2. Matching surface spots · Tail fibres read the surface like a hand reads a glove, and only matches dock.
  3. True · Marked coats stayed outside while marked genes entered, proving genes are DNA.
  4. They prune whichever strain grows common · Strict hunters crop the common strain the way predators crop one prey.
  5. Drip a panel of known viruses and watch which one bursts it · Because killing is precise, bursting marks the exact strain present.
  6. It can no longer dock · No matching spot means no docking, which is one route to resistance.
  7. No, strict matching gives clean answers · Tiny genomes plus ruthless matching made the cleanest system for watching genes.
  8. The surface spot changed · Range comes from spot matching, so escape points to the spot, not the hunter.
Worksheet · LightMySky