(a)[3]
Describe the cause of each of these conditions: Down’s syndrome; sickle cell anaemia.
(b(i))[4]
Complete the genetic diagram to show the possible blood groups of the second child of these parents.
(b(ii))[2]
State the probability of each of the following for the second child of these parents: being the same sex as the first child; having the same blood group as the first child.
(b(iii))[1]
Name the type of inheritance shown by the alleles that produce the blood group AB.