Predict and interpret patterns of inheritance Genetics Unit Predict and interpret patterns of inheritance

Probability The likelihood that a particular event will occur. The principle of probability can be used to predict the outcome of genetic crosses.

Punnett Square Punnett squares can be used to predict and compare the genetic variations that will result from a cross. Homozygous – Organisms that have two identical alleles for a particular trait. TT or tt Heterozygous – Organisms that have two different alleles for the same trait. Phenotype – physical characteristics Genotype – genetic makeup

Punnett Square (Monohybrid)

Punnett Squares (Dihybrid)

Incomplete Dominance One allele is not completely dominant over the other allele. The heterozygous phenotype is somewhere between the dominant and the recessive trait.

Codominance Both alleles are dominant and show up in the phenotype.

Multiple Alleles A gene with more than two alleles. This only means that there are more than two forms of the trait.

Traits controlled with two or more genes. Polygenic Traits

Characteristics of any organism are a result of an interaction between genes and environment. Genes provide a blueprint, but environmental factors can alter the finished product.