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IGCSEBiology
Trial Class

Original practice · 5 questions · 15 marks · about 17 minutes

Selective Breeding Practice Questions

Biology editorial review is supported by the named review panel. Reviewer participation may vary by guide. Checked against Cambridge IGCSE Biology 0610 (2026–2028); last reviewed August 2026.

These questions test your understanding of how humans use selective breeding to develop organisms with desired characteristics.

Before you open the answers

  • Attempt every question without notes.
  • Show working for calculations and write complete biological statements.
  • Use the suggested time as a guide, not a strict limit on the first attempt.

These are original practice questions. They do not reproduce an official Cambridge paper or official mark scheme.

  1. Question 1

    Paper 4 Both 4 marks Difficulty 3/5

    Describe the steps involved in selective breeding to produce cows that give more milk.

    Show model answer and marking guidance
    1. Select cows that produce the most milk from the herd.
    2. Breed these high-yielding cows with a bull from high-yielding stock.
    3. From the offspring, select those that give the most milk and breed them.
    4. Repeat over many generations: the herd's average milk yield increases.

  2. Question 2

    Paper 4 Extended 3 marks Difficulty 3/5

    State two advantages and one disadvantage of selective breeding.

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    1. Advantage: can produce organisms with desired characteristics (e.g. Higher yield, disease resistance).
    2. Advantage: no need for expensive technology: has been done for thousands of years.
    3. Disadvantage: reduces genetic diversity: inbreeding can lead to health problems / increased susceptibility to disease.

  3. Question 3

    Paper 4 Extended 3 marks Difficulty 4/5

    Explain why reduced genetic variation from selective breeding can be dangerous for a population.

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    1. All individuals become genetically similar.
    2. If a new disease appears, all individuals may be equally susceptible.
    3. The population lacks the variation needed for natural selection to act: could be wiped out.

  4. Question 4

    Paper 2 Core 2 marks Difficulty 1/5

    Define selective breeding (artificial selection).

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    1. Humans choose organisms with desirable characteristics to breed together.
    2. Over many generations, the desired characteristic becomes more common in the population.

  5. Question 5

    Paper 4 Both 3 marks Difficulty 3/5

    Give two examples of selective breeding in plants or animals.

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    1. Breeding wheat for higher grain yield / disease resistance.
    2. Breeding dogs for specific traits (size, temperament, working ability).
    3. Breeding chickens for larger eggs or faster growth.

Mark the set consistently

Award a point only when the idea is clearly present in the written answer. Correct any missed point in a complete sentence, then test the same skill on a different question several days later.

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