Loading...
Loading...
Unit 5 is the genetics-of-inheritance unit, and it is the most math-driven part of AP Biology after evolution. It covers meiosis as the source of genetic variation, Mendelian and non-Mendelian patterns, sex linkage, linked genes, pedigrees, and the chi-square test. Probability and careful Punnett-square reasoning earn the points here.
For US students. Live online coaching in your time zone (ET / CT / MT / PT), USD pricing.
How meiosis halves chromosome number and produces genetically unique gametes. The three sources of variation: crossing over (recombination) in prophase I, independent assortment of homologous pairs in metaphase I, and random fertilization. Contrasting meiosis with mitosis.
The law of segregation and the law of independent assortment. Monohybrid and dihybrid crosses, predicted phenotypic and genotypic ratios, and using probability rules (the rule of multiplication and the rule of addition) instead of large Punnett squares.
Incomplete dominance, codominance, multiple alleles (such as ABO blood type), pleiotropy, epistasis, and polygenic traits. How environment interacts with genotype to produce a phenotype.
X-linked inheritance and why recessive X-linked traits appear more often in males. Linked genes that travel together because they are on the same chromosome, and how recombination frequency reveals the distance between them.
Reading pedigrees to determine whether a trait is dominant, recessive, autosomal, or sex-linked. Using the chi-square test to decide whether observed offspring ratios differ significantly from expected ratios — a required quantitative skill in this unit.
Unit 5 is calculation-heavy. MCQs ask for offspring probabilities, blood-type outcomes, and recombination frequencies. The chi-square test appears in both sections and students must show the full reasoning, not just the number. FRQs typically give a cross or a pedigree and ask you to determine the inheritance pattern, predict ratios, and justify your conclusion — and at least one quantitative FRQ on the exam often draws on this unit’s statistics.
We treat Unit 5 as a problem-solving unit, not a memorization unit. Students learn to solve dihybrid and conditional-probability problems with the multiplication and addition rules so they are fast and accurate under time pressure. We drill the chi-square test as a repeatable five-step procedure and run pedigree after pedigree until pattern recognition is instant. Live online, US time zones.
AP Biology Unit 5 Heredity covers meiosis and the sources of genetic variation, Mendelian inheritance, non-Mendelian patterns such as incomplete dominance and codominance, sex linkage, linked genes and recombination, pedigree analysis, and the chi-square test.
Yes. Unit 5 is one of the most quantitative AP Biology units. It requires probability calculations for crosses, recombination frequency, and the chi-square statistical test, so strong arithmetic and a clear procedure are essential.
The College Board CED lists Unit 5 at approximately 8 to 11 percent of the multiple-choice section. This is published as a range, so treat it as approximate.
Tell us where you are stuck in Heredity and we will reply with a quick answer plus how we would coach it. No commitment.
WhatsApp is free from the US — no international call needed. Live online classes in your US time zone (ET/CT/MT/PT).
We teach this unit live online and grade your practice against the real College Board rubric. Faculty trained at AIIMS (All India Institute of Medical Sciences, India's top medical school).