GED Science Practice Test
Updated October 27, 2026
The GED Science test takes 90 minutes. Like Social Studies, most questions give you a short passage, a table, a graph or a description of an experiment, then ask what it shows. You can use the on-screen calculator on this test. Try the free questions below.
What GED Science covers
- Life science: cells, the human body, genetics, ecosystems and evolution.
- Physical science: matter, chemical reactions, energy, forces and motion.
- Earth and space science: the Earth’s systems, weather and climate, natural resources, and the solar system.
- Scientific practices: designing experiments, identifying variables, reading data and judging conclusions.
Free GED Science practice questions
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A student tests whether the amount of fertilizer affects tomato plant growth. Which is the dependent variable?Answer: CThe dependent variable is what is measured as a result: plant height. Fertilizer is the independent variable, and soil and water should be kept the same.
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Which organelle contains a cell's DNA?Answer: AIn plant and animal cells, DNA is stored in the nucleus. Mitochondria release energy, and ribosomes make proteins.
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In a food chain of grass, grasshopper, frog and hawk, which organism is the producer?Answer: DProducers make their own food through photosynthesis. Grass is the producer; the others are consumers.
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A car travels 120 kilometers in 2 hours. What is its average speed?Answer: BAverage speed = distance ÷ time = 120 km ÷ 2 h = 60 km/h.
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Water boils, turning from a liquid into a gas. This is an example of:Answer: CBoiling changes the state of water but not what it is made of, so it's a physical change. A chemical change makes a new substance.
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Which gas do plants take in from the air for photosynthesis?Answer: APlants take in carbon dioxide and water and use light energy to make sugar, releasing oxygen.
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A study finds that people who drink more coffee also sleep fewer hours. Which conclusion is best supported?Answer: BA correlation shows two things change together, but not which one causes the other, or whether something else causes both.
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Which structure in the human body exchanges oxygen and carbon dioxide with the blood?Answer: CGas exchange happens across the thin walls of the alveoli, the tiny air sacs in the lungs, which are surrounded by capillaries.
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In humans, the allele for brown eyes (B) is dominant over blue eyes (b). What fraction of children from a Bb × bb cross are expected to have blue eyes?Answer: CThe cross gives Bb, Bb, bb and bb, so half the offspring (bb) are expected to have blue eyes.
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A 2-kilogram object accelerates at 3 m/s². What net force acts on it?Answer: DForce = mass × acceleration = 2 × 3 = 6 newtons.
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What is the density of an object with a mass of 50 grams and a volume of 10 cubic centimeters?Answer: BDensity = mass ÷ volume = 50 ÷ 10 = 5 g/cm³.
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Which energy source is renewable?Answer: DWind is renewable because it's naturally replenished. Coal, natural gas and petroleum are fossil fuels that form over millions of years.
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In an ecosystem, decomposers such as fungi and bacteria mainly:Answer: ADecomposers break down dead plants and animals, recycling nutrients back into the ecosystem.
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Which layer of Earth is made of liquid metal and creates Earth's magnetic field?Answer: CThe outer core is liquid iron and nickel. Its movement generates Earth's magnetic field. The inner core is solid.
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A chemical equation shows 2H₂ + O₂ → 2H₂O. How many hydrogen atoms are on each side?Answer: B2H₂ has 2 × 2 = 4 hydrogen atoms, and 2H₂O also has 2 × 2 = 4. The equation is balanced.
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A vaccine helps protect against disease mainly by:Answer: BVaccines expose the immune system to a harmless form or part of a pathogen, so it can recognize and fight the real one faster later.
Tips for GED Science
For experiment questions, find what was changed on purpose (the independent variable), what was measured (the dependent variable) and what was kept the same. Then only accept a conclusion the data supports. See also the GED Math practice test.
Pass the GED test, one subject at a time
- All 171 questions across Math, Language Arts, Social Studies and Science
- An explanation for every answer, with the working shown for math
- Unlimited practice tests for each of the four subjects