Which of the following causes colour blindness?

(a) E is the gene for brown eye colour and e is the gene for blue eye colour. Which gene is (i) recessive, and (ii) dominant?

(b) Both father and mother have the genes Ee in their cells. What colour are their eyes?

(c) Which combination of genes in the zygote will produce children with blue eyes?

(d) Which combination of genes in the zygote will produce children with brown eyes?