A man with red-green colour blindness has a daughter with normal colour vision. This daughter has children with a man with normal colour vision. The condition is caused by a recessive X-linked allele.
What percentage of the daughter’s children is expected to be girls who carry the colour-blindness allele?
25%25\%25%
0%0\%0%
50%50\%50%
75%75\%75%
43 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.