2.7.3 Genetic disorders

Question 1

What is polydactyly?

Answer 1

Polydactyly – having extra fingers or toes – is caused
by a dominant allele of a gene and can therefore
be passed on by only one parent who has the disorder.

Question 2

What is Cystic fibrosis?

Answer 2

Cystic fibrosis (a disorder of cell membranes) must
be inherited from both parents. The parents may be
carriers of the disorder without actually having the
disorder themselves. It is caused by a recessive
allele of a gene and can therefore be passed on
by parents, neither of whom has the disorder

Question 3

How do we know if a bay will have one of these disorders?

Answer 3

Embryos can be screened for the alleles that

cause these and other genetic disorders.