12,241 verified 4-option questions Double-checked by independent solution

TEAS 7 Science: Scientific Reasoning practice questions

4 questions · answers open · no sign-up

These are original practice items written to the TEAS 7 blueprint (4 options, no penalty for wrong answers), not actual exam questions. Try each one before you open the answer.

What this topic covers

Science: Scientific Reasoning sits inside the Science section of the TEAS 7. Our bank holds 49 verified items tagged to it, and the 4 below are a fixed sample so the page stays the same every time you open it. Each one shows the reasoning, not just the letter.

The topic tag comes from our own items rather than from a published syllabus, so treat it as a map of what we cover. For the official section breakdown see the TEAS 7 page.

Science: Scientific Reasoning sample questions

Question 1

A researcher wants to test the effect of different amounts of sunlight on the growth of bean plants. She places three groups of plants under 2 hours, 6 hours, and 12 hours of sunlight per day, while keeping water, soil, and temperature constant. Which variable is the independent variable?

  1. A Water amount
  2. B Plant growth
  3. C Temperature
  4. D Amount of sunlight
Show the answer and explanation

Correct answer: D

The independent variable is the factor that the researcher manipulates. Here, the amount of sunlight is deliberately changed across groups.

Why the other options are wrong:
A: Water amount is a controlled variable, kept constant.
B: Plant growth is the dependent variable, measured as an outcome.
C: Temperature is a controlled variable, kept constant.

Question 2

A researcher designs an experiment to test the effect of temperature on the activity of an enzyme. She sets up three test tubes with identical substrate and enzyme concentrations, then incubates them at 20°C, 37°C, and 60°C. After 10 minutes, she measures the product concentration. She observes the highest product concentration at 37°C and very low product at 60°C. To improve the conclusion that temperature affects enzyme activity, which additional control should she include?

  1. A A test tube with boiled enzyme and substrate at 37°C
  2. B A test tube with enzyme but no substrate at 37°C only
  3. C A test tube with twice the substrate concentration at 37°C
  4. D A test tube with substrate but no enzyme at each temperature
Show the answer and explanation

Correct answer: D

Including a control without enzyme at each temperature accounts for any spontaneous substrate breakdown due to temperature, ensuring that the product measured originates from enzyme activity.

Why the other options are wrong:
A: Boiled enzyme is denatured but still tests for non‑enzymatic reaction at one temperature only; it lacks controls at other temperatures.
B: Testing enzyme without substrate at one temperature checks for enzyme autolysis but does not control for non‑enzymatic product formation at all temperatures.
C: Changing substrate concentration alters the reaction rate and does not serve as a control for temperature effects.

Question 3

A researcher wants to test whether a new drug reduces blood pressure. Which study design best controls for the placebo effect?

  1. A Open-label study where all participants receive the drug
  2. B Double-blind, placebo-controlled study
  3. C Observational study comparing drug users to non-users
  4. D Single-blind study with a placebo group
Show the answer and explanation

Correct answer: B

A double-blind, placebo-controlled design minimizes bias: neither participants nor researchers know who receives the drug or placebo, effectively controlling for the placebo effect and experimenter bias.

Why the other options are wrong:
A: Open-label studies have no blinding, so placebo effect is not controlled.
C: Observational studies lack randomization and control, making them prone to confounding variables and placebo effects.
D: Single-blind only blinds participants; researchers' knowledge can still introduce bias.

Question 4

A researcher wants to test the effect of a new fertilizer on plant growth. She applies the fertilizer to 10 plants and gives 10 other plants only water. All plants receive the same amount of sunlight and soil. What is the independent variable in this experiment?

  1. A Water
  2. B Amount of sunlight
  3. C Plant growth
  4. D Type of fertilizer (or no fertilizer)
Show the answer and explanation

Correct answer: D

The independent variable is the factor that is manipulated by the researcher. Here, the presence or absence of the new fertilizer is changed between the two groups.

Why the other options are wrong:
A: Water is part of the control condition but is not the variable being tested; the key manipulation is fertilizer.
B: Sunlight is a controlled variable, kept constant for all plants.
C: Plant growth is the dependent variable, measured as the outcome.

The whole TEAS 7 bank

4,659 verified questions with explanations, timed section tests with the real item counts and time limits, a review pool that brings back what you missed until you get it right, and an AI tutor that explains why. One payment per exam, or one bundle for all of them.

Get full access → About the TEAS 7

Related pages

All TEAS 7 sample questions 4 sections All Science questions 4 topics Science - Human Anatomy and Physiology with explanations Science: Biology with explanations Science: Chemistry with explanations HESI A2 sample questions with explanations NCLEX-RN sample questions with explanations

TEAS is a registered trademark of Assessment Technologies Institute, LLC; HESI is a registered trademark of Elsevier Inc. NCLEX and NCLEX-RN are registered trademarks of the National Council of State Boards of Nursing, Inc. (NCSBN). AdmitNurse is an independent practice service, not affiliated with or endorsed by any of these organizations.