B6: Inherited Disorders Flashcards
What is cystic fibrosis?
A genetic disorder of the cell membranes. It results in the body producing an excessive amount of thick, sticky mucus in the air passages and in the pancreas.
Is cystic fibrosis dominant or recessive?
The allele which causes CF is recessive.
What is a carrier?
Someone who carries the recessive allele of the disorder and so is not affected by it.
How does a child get cystic fibrosis?
The parents must either both be carrying the recessive gene or both have the disorder themselves.
If both parents are carriers of CF, what the likelihood of their child having it?
It’s a one in four chance.
What is polydactyly?
A genetic disorder where a baby is born with extra fingers or toes. It usually doesn’t cause any other problems so it isn’t life-threatening.
Polydactyly disease is cause by what kind of allele?
A dominant allele ‘D’.
How can polydactyly be inherited?
It can be inherited if just one parent carries the defective allele.
During the hat treatment are embryos screened for genetic disorders?
IVF, but it’s also possible to test DNA straight from the womb too.
Why is embryo screening a controversial process?
It implies that people with genetic problems are ‘undesirable’ - could increase prejudice
May come a point where everyone wants to choose the most desirable characteristics for their children (eg. green eyes, red hair)
What’s one pro and one con of embryonic screening?
Help to stop people suffering
Screening is expensive
