Cystic fibrosis is an inherited genetic condition.
It is caused by a mutation to a gene that codes for a protein regulating the movement of salt and water in and out of cells. This mutation produces a recessive allele.
Explain the meaning of these terms:
If a person has two mutated alleles for cystic fibrosis, they will suffer from symptoms including thick, sticky mucus in their lungs.
Why does a person need to inherit two mutated alleles to have cystic fibrosis?
Why does this condition cause breathing difficulties?
Two people are heterozygous carriers for cystic fibrosis and are expecting a baby.
Complete the Punnett square to work out the probability that the baby will have cystic fibrosis. Let FFF be the normal allele and fff be the mutated allele for cystic fibrosis.
| FFF | fff | |
|---|---|---|
| FFF | ||
| fff |
State the probability that the baby will develop cystic fibrosis.
Scientists are investigating the use of stem cells to treat cystic fibrosis in the lungs. Why might stem cells be able to repair damaged lung tissue?
State two reasons why medical treatments, such as new gene therapies or drugs, are tested on animals or laboratory-grown cells before being trialled on humans.