Inherited Disorders (OCR GCSE Biology A, Combined (Gateway Science Suite)): Revision Notes
📚 Revision Notes
6.1.7 Inherited Disorders
infoNote
Genetic disorders are caused by inheriting certain alleles.
Polydactyly: having extra fingers or toes
- Caused by a dominant allele
Cystic fibrosis: this is a disorder of the cell membranes, resulting in thick mucus in the airways and pancreas
- Caused by a recessive allele
- Both parents need to either be carriers (have one of the recessive alleles) or one must have CF themselves and the other is a carrier.
Embryonic screening allows scientists to observe whether the child will have a genetic condition or not.
- If the embryo is developed in the lab, cells can be taken from it and analysed
- DNA from embryos in the womb can also be extracted There are many economic, social and ethical issues surrounding embryonic screening.
| Arguments for embryonic screening | Arguments against embryonic screening |
|---|---|
| Reduces the number of people suffering (ethical). | Could encourage people to pick characteristics • creating designer babies (ethical). |
| Treating disorders is very expensive (economic). | It is expensive to carry out screening (economic). |
| There are many regulations in place to stop it getting out of hand (social). | May promote prejudice as it suggests that those with genetic disorders will not live a full life or are unwanted (social). |
| Decisions about terminating a pregnancy have to be made (social). | |
| The procedure can lead to a miscarriage (social). |