18.3

Selection

Cambridge IGCSE Biology (0610)  · Unit 18: Variation and selection  · 12 flashcards

Selection is topic 18.3 in the Cambridge IGCSE Biology (0610) syllabus , positioned in Unit 18 — Variation and selection , alongside Variation and Adaptive features.  In one line: Natural selection is the process where organisms with advantageous traits are more likely to survive and reproduce. These traits, determined by alleles, are then passed to offspring, increasing their frequency in the population over generations.

This topic is examined in Paper 1 (multiple-choice) and Papers 3/4 (theory), plus Paper 5 or Paper 6 (practical / alternative to practical). Past papers from 2022 to 2025 record 3 explicit questions on this topic — though the concept underpins many adjacent topics, so it is tested far more often than that figure suggests.

The deck below contains 12 flashcards — 3 definitions, 5 key concepts, 2 process cards and 2 application cards — covering the precise wording mark schemes reward.  Use the 3 definition cards to lock down command-word answers (define, state), then move on to the concept and application cards to handle explain, describe and compare questions.

Key definition

Natural selection

Natural selection is the process where organisms with advantageous traits are more likely to survive and reproduce. These traits, determined by alleles, are then passed to offspring, increasing their frequency in the population over generations.

Example: Peppered moths evolving darker coloration during industrial revolution.

What the Cambridge 0610 syllabus says

Official 2026-2028 spec

These are the exact learning objectives Cambridge sets for this topic. Match the command word (Describe, Explain, State, etc.) in your answer to score full marks.

  1. Describe Describe natural selection with reference to: (a) genetic variation within populations (b) production of many offspring (c) struggle for survival, including competition for resources (d) a greater chance of reproduction by individuals that are better adapted to the environment than others (e) these individuals pass on their alleles to the next generation
  2. Describe Describe selective breeding with reference to: (a) selection by humans of individuals with desirable features (b) crossing these individuals to produce the next generation (c) selection of offspring showing the desirable features
  3. Outline Outline how selective breeding by artificial selection is carried out over many generations to improve crop plants and domesticated animals and apply this to given contexts
  4. Describe Describe adaptation as the process, resulting from natural selection, by which populations become more suited to their environment over many generations Supplement
  5. Describe Describe the development of strains of antibiotic resistant bacteria as an example of natural selection Supplement
  6. Outline Outline the differences between natural and artificial selection Supplement
Definition Flip

What is natural selection?

Answer Flip

Natural selection is the process where organisms with advantageous traits are more likely to survive and reproduce. These traits, determined by alleles, are then passed to offspring, increasing their frequency in the population over generations.

Example: Peppered moths evolving darker coloration during industrial revolution.
Key Concept Flip

Describe the role of genetic variation in natural selection.

Answer Flip

Genetic variation provides the raw material for natural selection. Differences in alleles within a population lead to varied traits. Some traits improve survival/reproduction, causing these alleles to become more common over time.

Example: Antibiotic resistance in bacteria arises from mutations.
Key Concept Flip

Explain the 'struggle for survival' in the context of natural selection.

Answer Flip

The 'struggle for survival' refers to competition for limited resources like food, water, and mates. Organisms best adapted to secure these resources are more likely to survive, reproduce, and pass on their genes.

Example: Lions competing for prey on the savanna.
Key Concept Flip

What is the role of reproduction in the process of natural selection?

Answer Flip

Successful reproduction allows advantageous alleles to be passed on to the next generation. Individuals with traits that enhance their ability to reproduce are more likely to contribute to the gene pool.

Example: Male peacocks with brighter plumage attracting more mates.
Definition Flip

What is selective breeding?

Answer Flip

Selective breeding, or artificial selection, involves humans choosing individuals with desirable traits to breed, aiming to enhance those traits in future generations. This process is repeated over many generations.

Example: Breeding cows for increased milk production.
Key Concept Flip

Describe the steps involved in selective breeding.

Answer Flip

Selective breeding involves selecting individuals with desired traits, crossing them to produce offspring, and then selecting offspring that exhibit the desired traits for further breeding. This process is repeated over many generations.

Example: Breeding disease-resistant wheat.
Key Concept Flip

How is selective breeding used to improve crop plants?

Answer Flip

Selective breeding can enhance crop yield, disease resistance, and nutritional content. Farmers select plants with the best traits, breed them, and repeat this process over generations.

Example: Developing larger and sweeter corn varieties.
Key Concept Flip

How is selective breeding used to improve domesticated animals?

Answer Flip

Selective breeding is used to enhance traits like milk production in cows, meat yield in chickens, and docility in dogs. Breeders select animals with the best traits and breed them repeatedly.

Example: Breeding thoroughbred horses for speed.
Definition Flip

What is adaptation?

Answer Flip

Adaptation is the process, driven by natural selection, by which populations become better suited to their environment over many generations. It involves inherited traits that enhance survival and reproduction.

Example: Camouflage in insects adapting to specific environments.
Key Concept Flip

Explain antibiotic resistance in bacteria as an example of natural selection.

Answer Flip

Antibiotic resistance arises when bacteria with resistance genes survive antibiotic treatment and reproduce. Over time, the proportion of resistant bacteria increases in the population.

Example: MRSA (Methicillin-resistant Staphylococcus aureus).
Key Concept Flip

Outline a key difference between natural and artificial selection.

Answer Flip

Natural selection is driven by environmental pressures, favouring traits that enhance survival and reproduction in a specific environment, whereas artificial selection is driven by human preference for specific traits.

Example: Natural selection favors camouflage in prey animals, while artificial selection favors high milk production in cows.
Key Concept Flip

Describe how 'production of many offspring' influences natural selection.

Answer Flip

Producing many offspring increases the likelihood that some individuals will possess advantageous mutations. Even with high mortality rates, some offspring are likely to survive and pass on beneficial traits.

Example: Fish laying thousands of eggs, but only a few surviving to adulthood.

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18.2 Adaptive features 19.1 Energy flow

Key Questions: Selection

What is natural selection?

Natural selection is the process where organisms with advantageous traits are more likely to survive and reproduce. These traits, determined by alleles, are then passed to offspring, increasing their frequency in the population over generations.

Example: Peppered moths evolving darker coloration during industrial revolution.
What is selective breeding?

Selective breeding, or artificial selection, involves humans choosing individuals with desirable traits to breed, aiming to enhance those traits in future generations. This process is repeated over many generations.

Example: Breeding cows for increased milk production.
What is adaptation?

Adaptation is the process, driven by natural selection, by which populations become better suited to their environment over many generations. It involves inherited traits that enhance survival and reproduction.

Example: Camouflage in insects adapting to specific environments.

Tips to avoid common mistakes in Selection

More topics in Unit 18 — Variation and selection

Selection sits alongside these Biology decks in the same syllabus unit. Each uses the same spaced-repetition system, so progress in one informs the next.

18.1 Variation

12 flashcards
18.2 Adaptive features

9 flashcards

Cambridge syllabus keywords to use in your answers

These are the official Cambridge 0610 terms tagged to this section. Mark schemes credit responses that use the exact term — weave them into your answers verbatim rather than paraphrasing.

natural selection evolution survival of the fittest Darwin selective breeding artificial selection antibiotic resistance mutation advantage disadvantage

Key terms covered in this Selection deck

Every term below is defined in the flashcards above. Use the list as a quick recall test before your exam — if you can't define one of these in your own words, flip back to that card.

Natural selection
Selective breeding
Adaptation

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How to study this Selection deck

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