TEAS Science: Scientific Reasoning — Questions and Answers
Question 1: A researcher wants to test whether a new fertilizer increases plant growth. She grows 50 plants with the fertilizer and 50 plants without it under identical conditions. What is the control group?
- The 50 plants grown with the new fertilizer
- The 50 plants grown without the new fertilizer (Correct answer)
- The researcher observing the plants
- The type of soil used in the experiment
Correct answer: The 50 plants grown without the new fertilizer
The control group receives no treatment and serves as the baseline for comparison. The plants grown without fertilizer are the control; those with fertilizer are the experimental group.
Question 2: Which of the following BEST describes a scientific hypothesis?
- A proven scientific fact supported by multiple independent studies
- A testable, falsifiable prediction made before an experiment is conducted (Correct answer)
- A summary of data collected and analyzed during an experiment
- A universal law derived from decades of repeated observation
Correct answer: A testable, falsifiable prediction made before an experiment is conducted
A hypothesis is a testable, falsifiable prediction about the outcome of an experiment. It is proposed before data is collected, and it must be possible to prove it wrong.
Question 3: A student measures the volume of a liquid three times and records 45 mL, 46 mL, and 45 mL. These results BEST demonstrate which quality of measurement?
- Accuracy, because the measurements agree with each other
- Validity, because the experiment was repeated three times
- Precision, because the results are consistently close to each other (Correct answer)
- Reliability of the hypothesis, because similar results were obtained
Correct answer: Precision, because the results are consistently close to each other
Precision refers to the reproducibility of measurements — how closely repeated measurements agree with each other. Accuracy describes how close measurements are to the true value, which cannot be determined here without a known standard.
Question 4: On a graph displaying experimental results, the independent variable is plotted on which axis?
- The y-axis (vertical axis)
- The x-axis (horizontal axis) (Correct answer)
- Both axes equally, depending on the experiment
- Neither axis — the independent variable belongs only in a data table
Correct answer: The x-axis (horizontal axis)
By scientific convention, the independent variable — the one deliberately manipulated by the researcher — is plotted on the x-axis. The dependent variable (what is measured) goes on the y-axis.
Question 5: A study finds that cities with higher ice cream sales also have higher drowning rates. Which conclusion is MOST scientifically valid?
- Ice cream consumption directly increases the risk of drowning
- Drowning incidents cause an increase in ice cream sales
- A third variable, such as hot weather, likely influences both rates simultaneously (Correct answer)
- The dataset is invalid and should be completely discarded
Correct answer: A third variable, such as hot weather, likely influences both rates simultaneously
Correlation does not imply causation. A confounding variable — warm summer weather — independently increases both ice cream consumption and swimming activity (and thus drowning risk), explaining the correlation without any direct causal link.
Question 6: Which of the following is an example of qualitative data?
- A patient's body temperature recorded as 38.5°C
- The mass of a chemical sample measured in grams
- The color of a solution after a chemical reaction occurs (Correct answer)
- The number of bacterial colonies counted on a culture plate
Correct answer: The color of a solution after a chemical reaction occurs
Qualitative data describes non-numerical characteristics such as color, texture, smell, or appearance. Options A, B, and D are all numerical (quantitative) measurements.
TEAS Science: Scientific Reasoning
A researcher wants to test whether a new fertilizer increases plant growth.
She grows 50 plants with the fertilizer and 50 plants without it under identical conditions.
What is the control group?