Traits and Inheritance Have you wondered why you resemble the other people in your family?

Genes Mendel identified two sets of instructions for each characteristic. These instructions for an inherited trait are known as Genes.

Genes Each parent gives one set of genes. The offspring then has two forms of the same gene – one from each parent. These different forms are called Alleles The allele is either Dominant or Recessive Alleles are represented with letters – Capital for Dominant and lower case for recessive.

Phenotype The way in which your alleles are expressed is known as Phenotype. It’s what you look like.

Genotype When both alleles are shown together for the offspring – this is your Genotype. Genotype is always represented by two letters – the same letter.

Genotype Homozygous – Having two identical alleles for a trait. Heterozygous – Having two different alleles for a trait.

Quick Review Phenotype – the way you look. Genotype – written combination of alleles. Alleles – letters used to represent genes. Genes – instructions for trait.

Punnett Squares A graphic organizer to show all possible combinations of offspring from parents.