Some disorders are inherited. These disorders are caused by the inheritance of certain alleles.
- Polydactyly (having extra fingers or toes) is caused by a dominant allele.
- Cystic fibrosis (a disorder of cell membranes) is caused by a recessive allele.
- Students should make informed judgements about the economic, social and ethical issues concerning embryo screening, given appropriate information.
Explain why data is needed to answer scientific questions, and why it may be uncertain, incomplete or not available. Outline a simple ethical argument about the rights and wrongs of a new technology.