Cystic fibrosis (CF) is an inherited condition. A dominant allele (FFF) results in normal mucus production. A recessive allele (fff) results in the build-up of thick, sticky mucus, causing cystic fibrosis.
What is meant by the term dominant?
What are the two different genotypes of people who do not have symptoms of cystic fibrosis?
State the genotypes of both parents, and all possible genotypes of their offspring, for a cross between a heterozygous father and a heterozygous mother. Use the symbols FFF and fff.
What is the probability of these parents producing a child with cystic fibrosis?
What is the phenotype ratio of healthy children (non-sufferers) to children with cystic fibrosis?
Cystic fibrosis leads to thick, sticky mucus blocking the airways in the lungs. Suggest how this might affect the body's ability to perform aerobic respiration in muscle cells.
66 exam-style questions on Edexcel IGCSE Biology Inheritance. Each one has a worked solution and a mark scheme showing where the marks go.