The TEAS Science section is 50 questions in 60 minutes, and roughly half of them are anatomy and physiology. That single fact should shape how you study: if your time is limited, body systems earn more marks than anything else on this list. This guide condenses the whole section into the facts examiners actually test, with the wrong-answer traps flagged as you go. Last updated July 2026.
High-yield notes covering exactly what the TEAS Science questions test. Colored words are the ones exam writers swap into wrong answers — learn those cold.
The Cell
| Organelle | One-line job |
|---|---|
| Nucleus | Control center — holds DNA |
| Mitochondrion | “Powerhouse” — makes ATP |
| Ribosome | Builds proteins |
| Golgi apparatus | Modifies, packages & ships proteins |
| Lysosome | Digests waste |
| Cell membrane | Controls entry/exit — in ALL cells |
Cell Processes & Transport
- Cellular respiration: glucose + O₂ → ATP + CO₂ + water.
- Photosynthesis: light + CO₂ + water → glucose + O₂ (chloroplasts).
- Diffusion: high → low (no energy). Osmosis = diffusion of water.
- Active transport: low → high, against the gradient — needs ATP.
Genetics & DNA
- DNA pairs A–T, G–C. RNA swaps T for U (uracil) and is single-stranded.
- Strands are antiparallel: complement of 5′ AGC 3′ is 3′ TCG 5′.
- Transcription = DNA → RNA. Translation = RNA → protein (ribosome, tRNA brings amino acids).
- Gene = DNA coding one protein. Genotype = alleles you carry; phenotype = trait shown.
Body Systems — must-know
| System | Key fact |
|---|---|
| Cardiovascular | Arteries away, veins back. Pulmonary VEIN = oxygen-rich; pulmonary ARTERY = oxygen-poor. |
| Respiratory | Gas exchange in the alveoli. Diaphragm drives breathing. |
| Digestive | Most absorption in the small intestine. Stomach = most acidic. |
| Urinary | Kidneys filter blood & remove urea. |
| Nervous | Dendrites receive, axon sends. Threshold ~−55 mV. |
| Endocrine | Insulin lowers blood sugar; glucagon raises it. |
| Musculoskeletal | Tendon = muscle→bone; ligament = bone→bone. Calcium triggers contraction. |
| Integumentary | Skin = largest organ. Melanin blocks UV; UV makes vitamin D. |
| Immune | Innate = fast/nonspecific; adaptive = specific/learned. |
Chemistry Essentials
- Atomic number = # protons (= electrons if neutral). Mass number = protons + neutrons.
- Cation = + (lost e−, metals). Anion = − (gained e−, nonmetals). Isotopes differ in neutrons.
- Ionic bond = electrons transferred; covalent = shared.
- Physical change = same substance (melt, dissolve, boil). Chemical change = new substance (rust, burn).
Scientific Reasoning
- Independent variable = what you change; dependent = what you measure; control = untreated comparison.
- Correlation ≠ causation. Best evidence = controlled comparison with a control group.
- Most credible source = peer-reviewed research (not blogs/ads/social posts).
Frequently asked questions
How many questions are on the TEAS Science section?
The Science section has 50 questions with a 60-minute time limit. Human anatomy and physiology makes up the largest share, followed by biology, chemistry, and scientific reasoning.
What is the hardest part of TEAS Science?
Most students find anatomy and physiology hardest because of the sheer volume of terms. The fix is systematic: study one body system per day and focus on function rather than memorising every structure.
Do I need to memorise the periodic table?
No. You need atomic number versus mass number, how ions form, the difference between ionic and covalent bonds, and how to read the table - not to memorise it.
How long should I study for TEAS Science?
Plan around three to four weeks for Science alone if you are starting from scratch, studying one body system per day and finishing with mixed practice questions.
Keep going
- TEAS Reading Study Guide — main idea, inference, text structure
- TEAS Math Study Guide — formulas, conversions, word problems
- TEAS Science Study Guide — A&P, chemistry, scientific reasoning
- TEAS English Study Guide — grammar, punctuation, usage
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