Genetic dissorders

Question 1

What is cystic fibrosis?

Answer 1

This is a genetic dissorder that affects the respiratory and digestive systems where the air passages in lungs are coated with thicker and stickier mucus than normal.

Question 2

What two alleles are needed to inherit Cystic Fibrosis?

Answer 2

Two recessive alleles

Question 3

If both parents have one dominant and one recessive cystic fibrosis gene (Cc) work out the ratio of not inheriting the disease, the chance of the offspring inheriting the disease and chance of being a carrier of the disease.

Answer 3

75%
25%
50%

Question 4

Why can you be a carrier of Cystic Fibrosis?

Answer 4

Being a carrier implies that you have the allele for a disease but you do not have the disease because you only have one recessive allele.

Question 5

What is huntingdon’s disease?

Answer 5

This is a genetic dissorder that damages nerve cells in the brain and affects movement, cognition and mental health.

Question 6

If a dominant allele is needed to inherit Huntingdon’s disease, why can’t people with the disease be a carrier?

Answer 6

Being a carrier implies that you have the allele for a disease but you do not have the disease because you only have one recessive allele. If you have a dominant allele, it will be expressed and you will have the disease.