Pedigree Chart

Key Stage 4

A pedigree chart is a family tree showing particular heritable traits as they are passed down for one generation to the next.

Pedigree charts can be used to determine the alleles present in members of a family using the phenotype of other members.


This pedigree chart shows in the first generation a blue eyed female and a brown eyed male. Their offspring all have brown eyes. Since the brown eyed allele is dominant and blue eyed allele is recessive then each offspring in the second generation is heterozygous.	This pedigree chart shows the first generation has brown eyes. The second generation has 1 brown eyed offspring and two blue eyed offspring. Since blue eyes is the result of a recessive allele then both blue eyed people must be homozygous blue. The 2nd generation brown eyed offspring could be either heterozygous or homozygous.