Recent psychiatric research confirms that schizophrenia has a high heritability rate.
Leo's identical (monozygotic) twin brother, Oscar, has recently been diagnosed with schizophrenia. Leo believes that because they are identical twins and share 100% of their DNA, he is absolutely destined to develop the disorder as well.
With reference to the concepts of genotype and phenotype, explain why Leo is incorrect in assuming he will definitely develop schizophrenia.
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.