Giraffes have long necks. A student writes: 'Giraffes stretched their necks to reach leaves high up in trees. Their offspring were then born with longer necks.' Why is the student's explanation wrong?
Giraffes with longer necks cannot reach the leaves at the top of trees.
Changes during an animal's lifetime are not passed on to its offspring.
Giraffes evolved long necks so that they could run away from predators.
The necks of giraffes have stayed the same length for millions of years.
122 exam-style questions on OCR GCSE Biology 5.2 Natural selection and evolution, covering 5.2.1 Genetic variation within a population, 5.2.2 Developments in classification systems, 5.2.3 How evolution occurs through natural selection, 5.2.4 Evolution as change over time, 5.2.5 Evidence for evolution, and 5.2.6 Darwin and Wallace. Each one has a worked solution and a mark scheme showing where the marks go.