AP Biology Unit 5: Heredity — Tips & Strategies

Incomplete dominance (blending), codominance (both expressed), multiple alleles (e.g., blood type), polygenic inheritance (continuous variation), and epistasis (gene interaction).

Chi-square tests whether observed results differ significantly from expected Mendelian ratios. If the chi-square value exceeds the critical value, reject the null hypothesis.

Genes on the same chromosome tend to be inherited together (linked). Crossing over can separate them. Recombination frequency indicates distance: higher frequency = farther apart on the chromosome.

Always define alleles, write parental genotypes, then set up the cross. For dihybrid crosses, use FOIL or a 4x4 grid. Show all work on FRQs for full credit.