The DAT at a Glance
The Survey of Natural Sciences
Your understanding of biological and chemical concepts, as well as your proficiency in solving science problems, will be tested to its limits on the DAT. It's a science-intensive to say the least. On the Survey of Natural Sciences, you will have 90 minutes to answer 100 multiple-choice questions, subdivided into three science areas: Biology, Inorganic Chemistry, and Organic Chemistry.
Biology on the DAT
The Biology subsection contains 40 questions. Concepts tested include: Cell and Molecular Biology, including origin of life, cell processes, and more; Diversity of Life, Vertebrate Anatomy, Developmental Biology, Evolution, Ecology, and more.
Inorganic Chemistry on the DAT
Sometimes called General Chemistry, inorganic chemistry accounts for 30 questions on the survey. Concepts include: Acids and bases; atomic structure; periodic properties; gases; liquids and solids; nuclear reactions; and more.
Organic Chemistry on the DAT
Often thought the most difficult subsection, organic chemistry also accounts for 30 questions. Concepts include: Mechanisms, organic analysis, properties of molecules, stereochemistry; bonding; reactions; and nomenclature.
Try a sample question for DAT Biology:
The P680 chlorophyll A molecule of photosystem II:
- oxidizes glucose.
- oxidizes water.
- best absorbs light with a wavelength of 700nm.
- provides electrons that reduce NADH+.
- more than one of the above.
Answer & Explanation:
The answer is B.
The P680 molecule is involved in noncyclic electron flow. Light striking P680 excites electrons which rush off to fill the electron "holes" in the P700 chlorophyll. The P680 with its electron "holes" is a strong enough oxidizing agent to oxidize water, filling its electron holes and producing O2.
Choice A is incorrect because glucose is oxidized in cellular respiration. Photosynthesis is a reductive process. Choice C is incorrect because P680 is named according to its preferred absorption wavelength, namely 680nm. P700 absorbs best at 700nm. Choice D is incorrect because P700, when excited by light, provides the electrons that reduce NADH+. Choice E is incorrect because only choice B is correct.