A-Level Biology OCR B H422

patterns of monogenic (monohybrid) inheritance

To include the correct usage of the terms gene, allele (gene variant), locus, phenotype, genotype, dominant and recessive, heterozygous and homozygous and codominant.

gene mutations

To include cystic fibrosis, sickle cell anaemia, phenylketonuria (PKU) and Huntington’s disease.

patterns of inheritance which show codominance and multiple gene variants (alleles)

To include the inheritance of blood groups and HLA antigens in humans.

patterns of inheritance which show sex linkage and autosomal linkage

To include haemophilia (sex linkage) and ABO blood group and nail patella syndrome (autosomal linkage).

the use of model organisms to investigate patterns of inheritance

To include Drosophila melanogaster AND patterns of inheritance to include dihybrid inheritance AND the use of the chi-squared ($\chi^2$) test to analyse various patterns of inheritance.

chromosome mutations in humans

To include non-disjunction and translocations in the context of Turner’s syndrome, Klinefelter’s syndrome and Down’s syndrome.

the role of the genetic counsellor and the ethical issues involved in advising families where a genetic disease has been identified

To include pedigree analysis to predict the probability of genetic disease AND the use of genetic testing.