OAT Natural Sciences study guide
OAT Natural Sciences · Work through your exam, one topic at a time.
The Optometry Admission Test (OAT) Natural Sciences section is a multiple-choice component used by optometry programs to gauge readiness in biology, general chemistry, and organic chemistry. It is intended for applicants preparing for admission to professional optometry school, typically after completing prerequisite coursework. The section emphasizes reasoning with core concepts rather than isolated trivia: cell and molecular biology, genetics, physiology; stoichiometry, equilibrium, thermodynamics, acids and bases, electrochemistry; and organic structure, bonding, stereochemistry, functional-group reactivity, and spectroscopy. Because the three disciplines differ in style, strong preparation usually means cycling between them rather than finishing one before starting another, using timed practice to build stamina and accuracy under pressure. Topics on this exam: Biology, General Chemistry, and Organic Chemistry. The OAT Natural Sciences study guide has 3 sections and about 1,051 words.
01Biology: Molecular and Systems Reasoning
The OAT Biology section tests molecular and cellular biology, genetics, microbiology, and human anatomy and physiology, with smaller amounts of evolution and ecology. Most items ask you to connect a structure to a function or predict the result of a perturbation, not just recall a definition. Central dogma: DNA to RNA to protein. Transcription uses RNA polymerase and a DNA template; translation uses ribosomes, mRNA, and tRNAs.
372 words, about 2 min02General Chemistry: Quantitative Relationships
The OAT General Chemistry section tests stoichiometry, atomic structure and periodic trends, bonding, gases, solutions, thermodynamics, kinetics, equilibrium, acids and bases, redox, and electrochemistry. Many questions are calculation-based, so keep units consistent and track significant figures. Mole map: balance the equation first; convert mass to moles, apply mole ratios, and convert back. The limiting reagent is the reactant that produces the least product.
324 words, about 2 min03Organic Chemistry: Structure Controls Reactivity
The OAT Organic Chemistry section tests bonding and hybridization, nomenclature, stereochemistry, substitution and elimination, addition, aromaticity, carbonyl chemistry, and spectroscopy by IR and NMR. The exam rewards predicting products and identifying functional groups from data. Hybridization: carbon with four sigma bonds is sp3 and tetrahedral; three sigma bonds is sp2 and trigonal planar; two is sp and linear. Aromatic rings are planar, cyclic, conjugated, and follow Huckel's 4n+2 pi-electron rule.
355 words, about 2 min