We will show a Monohybrid cross and a Dihybrid cross along with the technique to determine what the outcomes of a certain cross.

Let us define some terms:

• Monohybrid - one trait, or sets of alleles
• Dihybrid - two traits
• Phenotype - What something looks like, or its physical appearance.
• Genotype - The genes it carries.
• Dominate - Only 1 gene needed for trait to be expressed.
• Recessive - Two genes needed for trait to be expressed.
• Heterozygous - Genes different, one dominate and one recessive.
• Homozygous - Both of the genes the same, two dominate, or two recessive, pure.

Monohybrid Cross

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• Homozygous Dominant with a Homozygous Recessive
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• Heterozygous with a Heterozygous
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• Heterozygous with a Homozygous

These three examples are all the types of problems that you will see for a monohybrid cross. The type of genes might change and with them the phenotypes. However the pattern will remain the same.

Dihybrid Cross

First I am not going to show you all the possible types of dihybrid crosses, it takes too much space. What I will show you is the most difficult type and the methods that you need to solve the problems.

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• Heterozygous with a heterozygous