Science (086) — AI-generated practice question

The student's argument is flawed because DNA-copying errors alone generate variation very slowly — the mechanism is precise enough that major errors cause the new DNA copy to fail and the cell dies.

Sexual reproduction generates variation differently and more effectively by combining DNA from two different individuals, each already carrying its own accumulated variations. This creates new combinations of variants in every offspring. Since these variants come from living individuals, they are assured to be non-lethal. Thus, sexual reproduction speeds up the generation of useful variation — far beyond what DNA-copying errors alone can achieve — providing a significant advantage for the survival and evolution of species.

Source: Chapter 7, Section 7.3.1 – Why the Sexual Mode of Reproduction?

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Examiners look for two distinct points:

1. Why DNA-copying errors alone are insufficient — they are too slow/precise; major errors are lethal.
2. How sexual reproduction adds to variation — by combining pre-existing accumulated variations from two individuals, creating novel, non-lethal combinations.

Avoid just saying "sexual reproduction creates more variation" — you must explain the mechanism (combination of two individuals' DNA) and why asexual variation alone is limited (slow rate, lethal errors). Three marks = three clear ideas, so structure your answer around these distinct points.