Science Practice Test 6 Welcome to your full GED practice test! You’ll face Science section, just like in the real exam. Stay focused and simulate real test conditions. You’ve got this! ⏰ Time’s up! Your responses have been automatically submitted. Check your score and review your mistakes carefully — each test makes you stronger. Science Practice Test 6 1 / 40 Which type of rock forms from cooled magma beneath Earth’s surface? A) Extrusive igneous B) Sedimentary C) Intrusive igneous D) Metamorphic Correct Answer: C Explanation: Intrusive igneous rocks cool slowly underground, forming large crystals. Correct Answer: C Explanation: Intrusive igneous rocks cool slowly underground, forming large crystals. 2 / 40 Which organ in the human body filters waste from the blood? A) Heart B) Kidney C) Liver D) Lungs Correct Answer: B Explanation: The kidneys remove waste products and excess water to form urine. Correct Answer: B Explanation: The kidneys remove waste products and excess water to form urine. 3 / 40 Which gas is most responsible for trapping heat in Earth’s atmosphere? A) Oxygen B) Nitrogen C) Carbon dioxide D) Helium Correct Answer: C Explanation: Carbon dioxide is a major greenhouse gas that absorbs heat energy. Correct Answer: C Explanation: Carbon dioxide is a major greenhouse gas that absorbs heat energy. 4 / 40 Which phase of the Moon occurs when the Moon is completely dark from Earth’s view? A) Full Moon B) New Moon C) First Quarter D) Third Quarter Correct Answer: B Explanation: A New Moon occurs when the Moon is positioned between Earth and the Sun. Correct Answer: B Explanation: A New Moon occurs when the Moon is positioned between Earth and the Sun. 5 / 40 The solid outer layer of Earth is called the . Check Correct Answer: crust Explanation: The crust is Earth’s thin, rocky outer surface. Correct Answer: crust Explanation: The crust is Earth’s thin, rocky outer surface. 6 / 40 The force that opposes motion between two touching surfaces is called . Check Correct Answer: friction Explanation: Friction slows down or stops moving objects. Correct Answer: friction Explanation: Friction slows down or stops moving objects. 7 / 40 The process of liquid water changing to gas is . Check Correct Answer: evaporation Explanation: Heat causes water molecules to move faster and become vapor. Correct Answer: evaporation Explanation: Heat causes water molecules to move faster and become vapor. 8 / 40 The green pigment in plant leaves that absorbs sunlight is called . Check Correct Answer: chlorophyll Explanation: Chlorophyll allows plants to capture light energy for photosynthesis. Correct Answer: chlorophyll Explanation: Chlorophyll allows plants to capture light energy for photosynthesis. 9 / 40 The smallest unit of an element that retains its properties is an . Check Correct Answer: atom Explanation: Atoms are the basic building blocks of all matter. Correct Answer: atom Explanation: Atoms are the basic building blocks of all matter. 10 / 40 The process by which plants lose water through their leaves is called . Check Correct Answer: transpiration Explanation: Transpiration moves water through the plant and releases it as vapor into the air. Correct Answer: transpiration Explanation: Transpiration moves water through the plant and releases it as vapor into the air. 11 / 40 Which organisms are decomposers? A) Fungi B) Earthworms C) Bacteria D) Oak trees Check Correct Answer: A, B, C Explanation: Decomposers break down dead matter. Oak trees are producers. FILL IN THE BLANK Correct Answer: A, B, C Explanation: Decomposers break down dead matter. Oak trees are producers. FILL IN THE BLANK 12 / 40 Which factors affect the speed of a chemical reaction? A) Temperature B) Surface area C) Concentration D) Color of reactants Check Correct Answer: A, B, C Explanation: Higher temperature, larger surface area, and higher concentration speed reactions. Color does not. Correct Answer: A, B, C Explanation: Higher temperature, larger surface area, and higher concentration speed reactions. Color does not. 13 / 40 Which situations involve potential energy? A) A stretched bowstring B) A book on a shelf C) A rolling skateboard D) A car speeding down a hill Check Correct Answer: A, B Explanation: Potential energy is stored energy. Rolling objects have kinetic energy. Correct Answer: A, B Explanation: Potential energy is stored energy. Rolling objects have kinetic energy. 14 / 40 Which processes are part of the carbon cycle? A) Photosynthesis B) Respiration C) Erosion D) Combustion Check Correct Answer: A, B, D Explanation: Plants absorb carbon dioxide, organisms release it, and burning fuels adds carbon dioxide. Correct Answer: A, B, D Explanation: Plants absorb carbon dioxide, organisms release it, and burning fuels adds carbon dioxide. 15 / 40 Which actions help protect biodiversity? A) Preserving forests B) Reducing pollution C) Overfishing D) Creating wildlife reserves Check Correct Answer: A, B, D Explanation: These actions protect species and ecosystems. Overfishing harms biodiversity. Correct Answer: A, B, D Explanation: These actions protect species and ecosystems. Overfishing harms biodiversity. 16 / 40 Which materials are good conductors of electricity? A) Copper B) Rubber C) Aluminum D) Glass Check Correct Answer: A, C Explanation: Metals conduct electricity well. Rubber and glass are insulators. Correct Answer: A, C Explanation: Metals conduct electricity well. Rubber and glass are insulators. 17 / 40 Which factors influence climate in a region? A) Latitude B) Altitude C) Ocean currents D) Color of local soil Check Correct Answer: A, B, C Explanation: Latitude, altitude, and ocean currents affect temperature and precipitation patterns. Correct Answer: A, B, C Explanation: Latitude, altitude, and ocean currents affect temperature and precipitation patterns. 18 / 40 Which signs indicate a chemical reaction has occurred? A) Change in temperature B) Formation of a gas C) Dissolving sugar in water D) New color appears Check Correct Answer: A, B, D Explanation: Heat changes, gas formation, and new colors are evidence of chemical change. Correct Answer: A, B, D Explanation: Heat changes, gas formation, and new colors are evidence of chemical change. 19 / 40 Which conditions can cause erosion? A) Wind B) Flowing water C) Acid rain D) Plant root growth Check Correct Answer: A, B, C Explanation: Wind, water, and acid rain contribute to erosion. Roots help prevent erosion. Correct Answer: A, B, C Explanation: Wind, water, and acid rain contribute to erosion. Roots help prevent erosion. 20 / 40 Which organisms are producers in an ecosystem? A) Oak trees B) Grass C) Bears D) Frogs Check Correct Answer: A, B Explanation: Producers make their own food using sunlight. Animals are consumers. Correct Answer: A, B Explanation: Producers make their own food using sunlight. Animals are consumers. 21 / 40 Which statement describes an effect of deforestation? A) Increased biodiversity B) Decreased soil erosion C) Loss of habitat for many species D) Higher oxygen production Correct Answer: C Explanation: Cutting trees destroys habitats and reduces biodiversity. MULTIPLE SELECT Correct Answer: C Explanation: Cutting trees destroys habitats and reduces biodiversity. MULTIPLE SELECT 22 / 40 Which tool is used to measure mass? A) Thermometer B) Balance C) Stopwatch D) Ruler Correct Answer: B Explanation: A balance measures mass in grams or kilograms. Correct Answer: B Explanation: A balance measures mass in grams or kilograms. 23 / 40 Which process forms clouds in the water cycle? A) Condensation B) Evaporation C) Precipitation D) Runoff Correct Answer: A Explanation: Condensation turns water vapor into droplets that form clouds. Correct Answer: A Explanation: Condensation turns water vapor into droplets that form clouds. 24 / 40 Which element is essential for forming proteins? A) Helium B) Carbon C) Nitrogen D) Neon Correct Answer: C Explanation: Proteins contain nitrogen, which is found in amino acids. Correct Answer: C Explanation: Proteins contain nitrogen, which is found in amino acids. 25 / 40 Which change is most clearly a chemical change? A) Breaking glass B) Burning paper C) Boiling water D) Melting ice Correct Answer: B Explanation: Burning creates new substances like ash and gases. The others are physical changes. Correct Answer: B Explanation: Burning creates new substances like ash and gases. The others are physical changes. 26 / 40 A student measures plant growth over four weeks. What type of graph is most appropriate? A) Pie chart B) Line graph C) Bar graph D) Diagram Correct Answer: B Explanation: A line graph shows changes over time clearly. Correct Answer: B Explanation: A line graph shows changes over time clearly. 27 / 40 Which type of energy transfer can occur through empty space? A) Radiation B) Conduction C) Convection D) Reflection Correct Answer: A Explanation: Radiation does not require matter, allowing sunlight to reach Earth. Correct Answer: A Explanation: Radiation does not require matter, allowing sunlight to reach Earth. 28 / 40 Which body system protects the body from harmful microorganisms? A) Muscular system B) Immune system C) Skeletal system D) Endocrine system Correct Answer: B Explanation: The immune system attacks and destroys harmful invaders. Correct Answer: B Explanation: The immune system attacks and destroys harmful invaders. 29 / 40 Which rock type forms from compacted sediment? A) Igneous B) Metamorphic C) Sedimentary D) Volcanic Correct Answer: C Explanation: Sedimentary rocks form when layers of sediment are pressed together over time. Correct Answer: C Explanation: Sedimentary rocks form when layers of sediment are pressed together over time. 30 / 40 What happens to the volume of a gas when temperature increases? A) It decreases B) It stays the same C) It increases D) It becomes zero Correct Answer: C Explanation: Gas particles move faster when heated, spreading out and increasing volume. Correct Answer: C Explanation: Gas particles move faster when heated, spreading out and increasing volume. 31 / 40 Which factor is most responsible for Earth’s seasons? A) Earth’s tilt B) Distance from the Sun C) Changing size of the Sun D) Moon phases Correct Answer: A Explanation: Earth’s tilt changes the amount of direct sunlight each hemisphere receives. Correct Answer: A Explanation: Earth’s tilt changes the amount of direct sunlight each hemisphere receives. 32 / 40 Which part of the cell is responsible for controlling cell activities? A) Mitochondria B) Nucleus C) Ribosomes D) Cytoplasm Correct Answer: B Explanation: The nucleus contains DNA, which directs all cell functions. Correct Answer: B Explanation: The nucleus contains DNA, which directs all cell functions. 33 / 40 Which type of heat transfer occurs when warm air rises and cool air sinks? A) Conduction B) Radiation C) Convection D) Fusion Correct Answer: C Explanation: Convection forms circular currents caused by temperature differences. Correct Answer: C Explanation: Convection forms circular currents caused by temperature differences. 34 / 40 Which planet has rings made mostly of ice and rock? A) Mars B) Saturn C) Venus D) Mercury Correct Answer: B Explanation: Saturn’s rings are the most visible and are mainly made of ice and rock particles. Correct Answer: B Explanation: Saturn’s rings are the most visible and are mainly made of ice and rock particles. 35 / 40 Which type of energy is found in food molecules? A) Mechanical B) Thermal C) Chemical D) Electrical Correct Answer: C Explanation: Food contains chemical energy that can be released through digestion. Correct Answer: C Explanation: Food contains chemical energy that can be released through digestion. 36 / 40 A student wants to test how salt affects the freezing point of water. What should be the dependent variable? A) Amount of salt B) Temperature at which water freezes C) Type of container D) Amount of stirring Correct Answer: B Explanation: The dependent variable is what is measured—in this case, the freezing point. Correct Answer: B Explanation: The dependent variable is what is measured—in this case, the freezing point. 37 / 40 What is the main source of energy that drives Earth’s weather? A) Earth’s core B) Moon’s gravity C) The Sun D) Earth’s rotation Correct Answer: C Explanation: The Sun heats Earth’s surface unevenly, causing wind, water movement, and weather patterns. Correct Answer: C Explanation: The Sun heats Earth’s surface unevenly, causing wind, water movement, and weather patterns. 38 / 40 Which process allows plants to release oxygen into the air? A) Digestion B) Photosynthesis C) Respiration D) Evaporation Correct Answer: B Explanation: Photosynthesis produces glucose and oxygen. Plants release oxygen through their leaves. Correct Answer: B Explanation: Photosynthesis produces glucose and oxygen. Plants release oxygen through their leaves. 39 / 40 What property of matter describes how much space an object takes up? A) Density B) Volume C) Mass D) Weight Correct Answer: B Explanation: Volume measures the amount of space a substance or object occupies. Correct Answer: B Explanation: Volume measures the amount of space a substance or object occupies. 40 / 40 Which organ system includes the lungs and trachea? A) Respiratory system B) Digestive system C) Circulatory system D) Endocrine system Correct Answer: A Explanation: The respiratory system allows the body to take in oxygen and remove carbon dioxide. Correct Answer: A Explanation: The respiratory system allows the body to take in oxygen and remove carbon dioxide. Your score isThe average score is 0%