Monohybrid inheritance

Learning objectives

Define genotype, phenotype, homozygous, heterozygous, dominant and recessive, and explain that a heterozygous individual is not pure-breeding

Use genetic diagrams and Punnett squares to predict the results of monohybrid crosses and calculate phenotypic ratios, including 1:1 and 3:1 ratios

Interpret pedigree diagrams showing the inheritance of a characteristic and explain the results of monohybrid crosses

Explain how a test cross with a homozygous recessive individual is used to identify an unknown genotype (Extended)

Describe codominance, including the inheritance of ABO blood groups with the alleles IA, IB and IO, and use genetic diagrams to predict the results of crosses involving codominance (Extended)

Describe sex-linked characteristics as those whose gene is on a sex chromosome, making the feature more common in one sex, use red–green colour blindness as an example and predict the results of sex-linked crosses (Extended)