Science (086) — AI-generated practice question

Environmental conditions determine which variations are preserved. Individuals with variations suited to the current environment survive and reproduce, passing those traits to the next generation — a process called natural selection.

Over time, this leads to accumulation of beneficial variations, gradually changing the species. For example, heat-resistant bacteria survive a heat wave and multiply, while others die out.

Source: Chapter 8, Section 8.1 — Accumulation of Variation During Reproduction

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• The key phrase examiners look for is "selection of variants by environmental factors" — this is directly from the textbook.
• Mention a concrete example (heat-resistant bacteria) to secure both marks.
• Avoid over-explaining heredity or DNA copying — the question is about which variations are preserved and the long-term effect on the species.
• Two clear points = 2 marks: (1) environment selects variants, (2) effect on species over time.