Selective Breeding and Genetic Engineering · seed 1 · A4, ink-friendly. The answer key prints on its own page for grown-ups.

Shaping life slowly or in one jump

Science · Genetics & Evolution · ages 15-16
Name ______________________   Date ____________

  1. Why does selective breeding take generations?

    • Genes refuse to pass to offspring
    • Breeders wait for permission yearly
    • Each round shifts traits only a little

  2. What do breeders repeat each generation?

    • Pick the best and breed them
    • Move genes across species
    • Clone the whole genome

  3. What is the danger of long inbreeding for one trait?

    • Genes jump to other species
    • Hidden flaws surface in the stock
    • The trait spreads too widely

  4. Why could selective breeding never have made bacteria brew human insulin?

    • Bacteria carry no human genes to select from
    • Insulin kills all bacteria
    • Bacteria divide too slowly

  5. A pest resistant crop is needed in one season. Which route fits, and why?

    • Selective breeding, since it is natural
    • Genetic engineering, since one moved gene acts at once
    • Inbreeding, since it is fastest

  6. A debate over an engineered crop should weigh what?

    • Nothing, since all crops are identical
    • Only the speed of the lab work
    • One benefit against one objection for that crop

  7. A herd bred only for speed now falls ill easily. What happened, and what fixes it?

    • Inbreeding surfaced flaws, so outcross to refresh variation
    • Genes wore out, so rest the herd
    • A virus evolved, so vaccinate the herd

  8. A student says prize wheat crossed with wild wheat is genetic engineering. What is the error?

    • Wild wheat has no genes
    • Crossing stays inside breeding, since no gene was moved in a lab
    • Wheat cannot be bred at all
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Answer key

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

Shaping life slowly or in one jump W1-mt_a3zTtiYrR2-s1

  1. Each round shifts traits only a little · Small shifts per round need many rounds to pile up.
  2. Pick the best and breed them · Choosing parents with wanted traits each round slowly shifts the stock.
  3. Hidden flaws surface in the stock · Close relatives pair faulty copies that outcrossing would have masked.
  4. Bacteria carry no human genes to select from · Selection only reshuffles genes a species already holds.
  5. Genetic engineering, since one moved gene acts at once · A single inserted gene gives the trait in one generation.
  6. One benefit against one objection for that crop · Power demands care: test benefits against risks case by case.
  7. Inbreeding surfaced flaws, so outcross to refresh variation · Narrow breeding for one trait cost the herd its hidden health.
  8. Crossing stays inside breeding, since no gene was moved in a lab · Crossing and selecting is breeding, even when the parents differ.
Worksheet · LightMySky