Praxis General Science Practice Test
Praxis General Science (5436) practice addresses core ideas from biology, chemistry, physics, and Earth and space science. The question bank samples topics such as water transport in plants, cell membranes, natural selection, ecosystem responses, solution concentration, density, forces, climate, and Earth's seasons. These examples connect scientific principles with measurements and observable phenomena.
Exam overview
About the Praxis General Science Exam
Questions call for selecting a suitable scientific explanation, interpreting conditions in a scenario, and applying quantitative relationships. Biology examples involve osmosis, plant water movement, adaptation across generations, and interactions between organisms and resources. Chemistry and physical science items use concentration, molarity, density, mass, volume, and force; solving them requires choosing the relevant relationship and keeping units consistent. Earth and space science examples ask learners to distinguish long-term atmospheric trends from other processes and relate seasonal patterns to Earth's orientation and motion. These skills reflect science teaching tasks such as explaining cause and effect, using evidence from observations, and checking whether a numerical result is physically reasonable. Practice across these areas can help identify concepts that need clearer explanations or more work with units and calculations.
Sample Practice Questions
Review a selection from this exam's published US Practice Tests practice bank.
Which process moves water from a plant's roots to its leaves as water evaporates from leaf surfaces?
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Correct answer: BEvaporation from leaf surfaces creates tension that helps pull a continuous column of water upward through xylem vessels. This process is commonly called transpiration pull.
A metal cube has a mass of 156 grams and a volume of 20 cubic centimeters. What is its density?
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Correct answer: BDensity is mass divided by volume: 156 g ÷ 20 cm³ = 7.8 g/cm³.
A long-term increase in the average temperature of Earth's lower atmosphere is most directly associated with which process?
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Correct answer: AGreenhouse gases absorb some infrared radiation emitted by Earth's surface and re-emit it in multiple directions, reducing the rate at which energy escapes to space and warming the lower atmosphere.
A red blood cell is placed in a solution with the same effective solute concentration as its interior. What is the expected net movement of water across its membrane?
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Correct answer: CIn an isotonic solution, water molecules move across the membrane in both directions at comparable rates. There is no net water movement, so the cell's volume is generally stable.
A solution is made by dissolving 10 grams of salt and adding water until the total solution volume is 2 liters. What is its concentration in grams per liter?
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Correct answer: BConcentration in grams per liter is solute mass divided by solution volume: 10 g ÷ 2 L = 5 g/L.
A solution contains 0.20 moles of glucose in 0.50 liters of solution. What is its molarity?
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Correct answer: CMolarity is the number of moles of solute divided by the volume of solution in liters: 0.20 mol ÷ 0.50 L = 0.40 mol/L, or 0.40 M.
A population of bacteria becomes resistant to an antibiotic over many generations. Which explanation best describes this change?
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Correct answer: CNatural selection increases the frequency of heritable resistance when resistant bacteria survive treatment and leave more offspring than susceptible bacteria. The antibiotic selects among variations; it does not cause all individuals to adapt deliberately.
How to use this practice test
The free US Practice Tests practice session presents up to 20 randomly selected questions from its 50-question Praxis General Science bank. Submit your answers to see results after the session, then use missed items to pinpoint concepts or calculations to revisit, such as molarity, density, osmosis, or force.
Preparation tips
- Practice calculating density and solution concentration; write the units at each step and distinguish grams per liter from moles per liter.
- For osmosis questions, compare effective solute concentrations on each side of the membrane before predicting net water movement.
- Explain biological cause-and-effect sequences, including how inherited variation and antibiotic exposure can change a bacterial population over generations.
- Review force diagrams for objects at rest, identifying weight and the normal force and applying the condition of zero vertical acceleration.
- Connect Earth science observations to mechanisms: distinguish a long-term atmospheric temperature trend from the axial tilt that produces seasonal changes.