The Survey of the Natural Sciences is the largest section of the Dental Admission Test, and it is a test of breadth. This article walks through its content outline as published in the American Dental Association's DAT 2026 Candidate Guide (updated December 2025). For the whole exam in one view, see What to Expect on the DAT.
Size and time
The guide describes the section as 100 items drawn from Biology, General Chemistry, and Organic Chemistry, and its administration schedule gives it 90 minutes. It is the first timed section of the test day. The item counts by discipline are:
- Biology: 40 items
- General Chemistry: 30 items
- Organic Chemistry: 30 items
Some questions on the DAT are experimental and unscored; the guide says they look the same as scored questions, and that candidates are not penalized for guessing. Both U.S. customary and metric units appear on the exam.
Biology (40 items)
The guide groups biology into five areas, each of which also includes "integrated relationships" among topics:
- Cell and Molecular Biology: cell metabolism (including photosynthesis and enzymology), cellular processes such as membrane transport and signal transduction, thermodynamics, mitosis and meiosis, cell structure and function, experimental cell biology, and biomolecules.
- Diversity of Life: viruses, Archaebacteria, Eubacteria, Fungi, Protista, Plantae, and Animalia.
- Structure and Function of Systems: integumentary, skeletal, muscular, circulatory, lymphatic and immune, digestive, respiratory, urinary, nervous and sensory, endocrine, and reproductive.
- Genetics: molecular, human, classical, and chromosomal genetics, genetic technology, developmental mechanisms, genomics, gene expression, and epigenetics.
- Evolution and Ecology: natural selection, population genetics and speciation, animal behavior, and population, community, and ecosystem ecology.
The guide does not give item counts for these five areas, so any study plan that assigns each a fixed number of questions is an estimate, not an official figure.
General Chemistry (30 items)
The general chemistry outline has twelve topics: stoichiometry and general concepts; gases (kinetic molecular theory and the Dalton, Boyle, Charles, and ideal gas laws); liquids and solids; solutions; acids and bases; chemical equilibria, including Le Chatelier's principle; thermodynamics and thermochemistry; chemical kinetics (rate laws, activation energy, half-life); oxidation-reduction reactions; atomic and molecular structure; periodic properties; and nuclear reactions. A thirteenth entry, Laboratory, covers basic techniques, equipment, error analysis, safety, and data analysis.
The guide states that a periodic table image is available to candidates during the General Chemistry portion, so memorizing it is not the goal. Knowing how to use periodic trends is. The outline also names calculations repeatedly: concentration, pH, electrochemical calculations, and calculations from balanced equations. The guide lists calculating devices as prohibited in the testing area and shows an on-screen calculator only for the Quantitative Reasoning section, so practice the chemistry arithmetic by hand.
Organic Chemistry (30 items)
The guide includes a notice that the organic chemistry specifications were to be updated, starting in April 2026, with simpler topic names and a more detailed list of subtopics, and that this was not meant to change the content in a major way. It tells candidates to follow the specifications in effect on their test date and to check the DAT website. The version printed in the guide after the update lists these groups:
- Mechanisms: curved arrows, single mechanisms (resonance, free radical, proton transfer, addition, elimination, substitution, rearrangements, and others such as Diels-Alder), combined mechanisms, and reaction coordinate diagrams.
- Chemical Synthesis: one-step reactions (SN1, SN2, E1, E2, alkenes and alkynes, alcohols, ethers and epoxides, radical reactions, aromatics, carboxylic acids and derivatives, ketones and aldehydes, alpha-carbonyl compounds), two-step and multi-step synthesis, and reactivity across several functional groups.
- Acid-Base Chemistry: ranking acidity and basicity, structure analysis (charge, size, electronegativity, resonance, inductive effect, hybridization, sterics), and prediction of products and equilibria.
- Chemical and Physical Properties of Molecules: polarity, intermolecular forces, solubility, melting and boiling points; laboratory techniques such as chromatography, extraction, recrystallization, and distillation; and spectroscopy (1H NMR, 13C NMR, infrared, and multi-spectra).
- Structural Evaluation: nomenclature (functional groups, IUPAC rules), stereochemistry (conformations, isomer relationships, chirality), and structure and bonding (aromaticity, hybridization, resonance, orbitals, bond angles and lengths).
What the outline suggests about preparation
Because the section mixes three disciplines in one 90-minute block, the outline rewards steady coverage over deep specialization. About 40 percent of the items are biology, and the other 60 percent are chemistry, so a student who is strong in biology but weak in organic mechanisms is leaving a large share of the section at risk. Read the guide's topic lists as a checklist and mark each line as confident, shaky, or untouched. Spectroscopy, mechanisms, and equilibria all appear by name and are good candidates for repeated practice.
Scores on the DAT are reported on a scale of 200 to 600 in 10-point increments, and the guide notes there is no official passing score; each dental program decides what it considers acceptable.
Practice DAT questions with explanations and timed practice tests.