Biology Unit 2 – Sickle Cell Inheritance


Genetic inheritance explored through the prevalence of Sickle Cell Anaemia in a family.

Program Overview

Students use real family history data to take on the role of a genetic counsellor and interrogate Sickle Cell Anaemia through two branches of a family tree.

Students will use patient interviews and review medical information to construct a pedigree, then run DNA samples through gel electrophoresis to determine genotype. Students will explore the advantages to being heterozygous for this co-dominant trait and construct Punnett squares to predict chances of future offspring having either the trait (heterozygous) or the disease (homozygous for Sickle Cell allele).

As the genetic counsellor they will also advise on lifestyle choices and their impacts on living with the disease.

Curriculum Focus

VCE Biology Unit 1 – AOS 1: How is inheritance explained?

The program will address the following study design dot points:

  • Genotypes and phenotypes
    • the use of symbols in the writing of genotypes for the alleles present at a particular gene locus 
    • the expression of dominant and recessive phenotypes, including codominance and incomplete dominance 
    • proportionate influences of genetic material, and environmental and epigenetic factors, on phenotypes 
  • Patterns of inheritance
    • pedigree charts and patterns of inheritance, including autosomal and sex-linked inheritance 
    • predicted genetic outcomes for a monohybrid cross and a monohybrid test cross 
    • predicted genetic outcomes for two genes that are either linked or assort independently. 

Students will also be shown the location of the Sickle Cell allele on chromosome 11, touching on karyotypes as a visual representation of chromosomes.

Additionally, it gives students a good introduction into gel electrophoresis as a preview of what they can expect in Unit 3 Biology.