Sex-linkage (CIE IGCSE Biology SUPPLEMENT)

This fully-resourced lesson has been designed to cover the specification points about sex-linked characteristics as detailed in the supplement section of topic 17 (inheritance) of the CIE IGCSE Biology specification This resource consists of an engaging and detailed PowerPoint and an accompanying worksheet, which has been differentiated two ways so students who find the tasks difficult are given assistance to result in good outcomes. The lesson builds on the knowledge from earlier in the topic on monohybrid crosses and sex determination to show students how to draw genetic diagrams to calculate offspring outcomes when the gene is carried on the sex chromosomes. Step by step guides are used to demonstrate how to write the genotypes and gametes in these disorders by including the sex chromosomes to show gender. The lesson focuses on red-green colour blindness and haemophilia and builds up to questions on a pedigree tree to challenge the students to apply their new knowledge.

This lesson has been designed for GCSE-aged students who are studying the CIE IGCSE Biology course but is suitable for A-level students who are looking at these types of genetic disorders.