Science Diagnostic Test
Test your ATI TEAS 7 knowledge with real exam-style questions and get instant feedback.
The TEAS 7 Science section is the largest section on the exam. You get 50 questions in 60 minutes, which works out to about 72 seconds per question. The content spans four areas: human anatomy and physiology, biology, chemistry, and scientific reasoning. Anatomy and physiology alone accounts for 18 of the scored questions, so it deserves the bulk of your study time[reference:0].
This page gives you five of the hardest Science questions we have on record, step-by-step explanations for each one, a skills checklist, and a study plan you can start today.
What the TEAS 7 Science Section Covers
Every question falls into one of four content areas.
| Content Area | Scored Questions | What It Tests |
|---|---|---|
| Human Anatomy and Physiology | 18 | Body systems, organs, tissues, homeostasis, and how structure relates to function |
| Biology | 9 | Macromolecules, cell structure, DNA and protein synthesis, cell division, genetics, and metabolism |
| Chemistry | 8 | Atomic structure, the periodic table, chemical bonds, reactions, acids and bases, and solutions |
| Scientific Reasoning | 9 | The scientific method, experimental design, variables, data interpretation, and evaluating evidence |
Of the 50 total questions, 44 are scored and 6 are unscored pretest items that ATI uses to trial future questions. You will not know which are which, so treat every question as if it counts[reference:1].
How to Use This Practice Test
Do not just read the questions and scroll to the answers. Follow this order instead:
- Set a timer. Give yourself 6 minutes for all five questions. That matches the real exam pace.
- Write down your answer before checking. Commit to a choice so you can see your actual reasoning later.
- Read the explanation even when you are right. A lucky guess and a correct answer look identical on a score report but they are not the same thing.
- Log your misses by topic. If three of your five misses are chemistry, that is your study target for the week.
- Retake the set after 48 hours. Spaced repetition is what moves material into long term memory.
TEAS Science Skills Checklist
Before test day, you should be able to do each of the following without hesitation.
- Name the major organs and primary functions of the cardiovascular, respiratory, nervous, digestive, renal, and endocrine systems
- Explain how the body maintains homeostasis through feedback loops
- Identify the four tissue types and give an example of where each is found
- Describe the structure and function of the cell membrane, mitochondria, ribosomes, and nucleus
- Explain the roles of DNA, RNA, and proteins in gene expression
- Distinguish between mitosis and meiosis
- Identify the four macromolecules and their building blocks
- Read a periodic table and determine atomic number, mass number, and valence electrons
- Distinguish between ionic, covalent, and hydrogen bonds
- Balance a simple chemical equation and identify the type of reaction
- Explain the difference between acids and bases using the pH scale
- Identify the independent variable, dependent variable, and control group in an experiment
- Interpret data from a graph, table, or chart and draw a valid conclusion
- Distinguish between correlation and causation
Top 5 Most Challenging TEAS Science Questions
We pulled answer data from nearly 15,000 test takers who worked through our question bank. The five questions below were missed by 70% to 80% of them. That is not a sign the questions are unfair. It is a sign that these five skills are the ones most students skip.
Question 1: Cell Organelle Function
Which organelle is primarily responsible for producing ATP during aerobic cellular respiration?
A. Ribosome B. Mitochondrion C. Lysosome D. Golgi apparatus
Answer: B
Explanation: Mitochondria generate most of a cell's ATP through aerobic cellular respiration. Ribosomes synthesize proteins, lysosomes digest cellular materials, and the Golgi apparatus modifies and packages proteins[reference:2].
Question 2: Gas Exchange in the Lungs
Which structure is the primary site of gas exchange in the lungs?
A. Bronchi B. Alveoli C. Trachea D. Pleura
Answer: B
Explanation: Alveoli are tiny air sacs surrounded by capillaries. Their thin walls allow oxygen to diffuse into the blood while carbon dioxide diffuses from the blood into the alveolar air. The bronchi and trachea conduct air, and the pleura is the membrane that surrounds the lungs[reference:3].
Question 3: DNA and RNA Bases
Which of the following bases is found in RNA but is absent from DNA?
A. Adenine B. Uracil C. Cytosine D. Thymine
Answer: B
Explanation: RNA uses uracil in place of the thymine found in DNA. Adenine, cytosine, and guanine are found in both molecules. This is a common trap question because students often remember that thymine pairs with adenine and assume it appears in both nucleic acids[reference:4].
Question 4: Chemical vs. Physical Change
Which of the following is an example of a chemical change?
A. Ice melting into water B. Sugar dissolving in tea C. Iron rusting D. Glass shattering
Answer: C
Explanation: Iron rusting is oxidation, which produces new substances called iron oxides. That makes it a chemical change. Melting, dissolving, and shattering are physical changes because the chemical composition of the substance does not change[reference:5].
Question 5: Scientific Reasoning and Experimental Design
A researcher wants to determine whether increasing fertilizer affects plant growth. Which variable should the researcher manipulate?
A. Plant height B. Amount of fertilizer C. Type of measuring ruler D. Number of measurements recorded
Answer: B
Explanation: The independent variable is the factor deliberately changed by the researcher. Here, that factor is the amount of fertilizer. Plant growth would be the dependent variable because it is what the researcher measures in response to the change. The type of ruler and number of measurements are controlled or procedural details, not variables being tested[reference:6].
Score Your Practice Set
| Correct | What It Means | Next Step |
|---|---|---|
| 5 of 5 | Science is a strength | Move to timed full length practice |
| 4 of 5 | Solid, one weak spot | Review the topic you missed and drill 20 questions |
| 3 of 5 | Gaps are showing | Reread the explanations, then retake in 48 hours |
| 0 to 2 of 5 | Fundamentals need work | Start with the skills checklist before more practice |
Nursing programs set their own minimum Science scores, and the range is wide. Some schools require as low as 45.8%, while others require 55% or higher. Most competitive programs want a total TEAS score in the 60% to 70% range. Check your program's requirements directly rather than guessing[reference:7].
Build a Four Week Science Plan
Week 1: Foundations and scientific reasoning. Take a diagnostic practice test to find your weak systems. Review the scientific method, independent and dependent variables, and how to read graphs and tables. These skills apply across every other science topic.
Week 2: High yield anatomy and physiology. Cardiovascular, respiratory, nervous, and renal systems show up most often. Study two systems per day using diagrams and flowcharts. Draw each system from memory and list the structure, function, and one common failure scenario for each organ.
Week 3: Biology and chemistry. Drill macromolecules, DNA to RNA to protein, mitosis versus meiosis, atomic structure, the periodic table, chemical bonds, and acids and bases. These topics are smaller in question count but easy to forget if you skip them.
Week 4: Review only. No new material. Rework every question you missed across the previous three weeks and confirm you can explain why the wrong answers are wrong. Take one full timed Science section under exam conditions.
Ready for Full Length Practice?
Five questions is a diagnostic, not a preparation plan. If you want structured review with video lessons, a full question bank, and progress tracking, our TEAS 7 course covers all four sections and includes over 2,650 practice questions, 300 digital flashcards, and 200 instructional videos. It comes with a money back guarantee and works on mobile.