Dr. Vance is studying a pair of monozygotic twins who were reared apart. He notes that while both twins inherited the same genetic predisposition for high athletic ability, only the twin who underwent intensive physical training went on to become an elite marathon runner, while the other did not.
Which of the following statements best explains this outcome using concepts from the biological approach?
The twins have developed different genotypes because the intensive physical training directly altered the runner's inherited DNA sequence.
The twins have different phenotypes because monozygotic twins share only 50%50\%50% of their genetic material, meaning their genetic potentials were inherently different.
The twins share the same genotype, but have developed different phenotypes because environmental factors have influenced how their genetic makeup is expressed.
The twins share the same phenotype, but have developed different genotypes because physical exercise has modified their underlying biological systems.
48 exam-style questions on AQA A Level Psychology Biological approach. Each one has a worked solution and a mark scheme showing where the marks go.