In an annual plant population, deeper roots increase the chance of surviving a dry summer. Scientists compare Darwin's theory with the idea that characteristics developed during an organism's life can be inherited.
Which observation provides the strongest support for Darwin's theory rather than the alternative idea?
Before the dry summers, deep-rooted parents tended to produce deep-rooted offspring in moist soil.
Measurements of the same plants showed that their roots grew deeper as the soil dried.
Plants exposed to drought produced offspring with deeper roots than the parents had before exposure.
Measurements showed that mean root depth increased after several dry summers.
71 exam-style questions on AQA GCSE Biology 6.3 The development of understanding of genetics and evolution, covering 6.3.1 Theory of evolution, 6.3.2 Speciation, 6.3.3 The understanding of genetics, 6.3.4 Evidence for evolution, 6.3.5 Fossils, 6.3.6 Extinction, and 6.3.7 Resistant bacteria. Each one has a worked solution and a mark scheme showing where the marks go.