Casey has blood group B. One of Casey's parents has blood group O.
Morgan has blood group AB. Casey and Morgan are expecting a child.
Explain how the blood groups of Casey and Casey's parent can be used to determine Casey's genotype.
Calculate the probability that a child of Casey and Morgan will have blood group A.
Show your working.
71 exam-style questions on Edexcel GCSE Biology 3.3 Inheritance, covering 3.3.1 Gregor Mendel and the basis of genetics, 3.3.2 Alleles and inherited characteristics, 3.3.3 Monohybrid inheritance, 3.3.4 Determination of sex at fertilisation, 3.3.5 Outcomes from monohybrid crosses, 3.3.6 Inheritance of ABO blood groups, 3.3.7 Inheritance of sex-linked disorders, and 3.3.8 Multiple genes and phenotypic features. Each one has a worked solution and a mark scheme showing where the marks go.