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1In the human circulatory system, which chamber of the heart pumps oxygen-rich blood out to the body?
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Answer: Left ventricle
The left ventricle has the thickest muscular wall and pumps oxygenated blood through the aorta to the rest of the body. The right ventricle pumps deoxygenated blood to the lungs.
2The Greek words "homeo" and "stasis" together describe
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Answer: keeping a stable internal environment
Homeostasis is maintaining balance in the body.
3Why is it important for scientists to repeat an experiment multiple times before drawing a conclusion?
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Answer: Repeated trials help confirm that results are consistent and not due to chance or error
Running multiple trials allows scientists to check whether results are consistent and reliable rather than the product of random chance or measurement error, strengthening the validity of a conclusion.
4A mineral sample has a mass of 6 grams and a volume of 3 cubic centimeters. What is the density of the sample?
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Answer: 2 g/cm3
Density = mass / volume = 6 g / 3 cm3 = 2 g/cm3. Distractors come from adding or multiplying the values instead of dividing.
5Which body system is primarily responsible for breaking down food into nutrients the body can absorb?
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Answer: Digestive system
The digestive system mechanically and chemically breaks down food into nutrient molecules that can be absorbed into the bloodstream.
6What is the main function of the mitochondria?
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Answer: to release energy for the cell
Mitochondria carry out cellular respiration.
7A wave has a frequency of 5 Hz and a wavelength of 2 meters. Using the formula v = fλ, what is the wave's speed?
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Answer: 10 m/s
Wave speed = frequency × wavelength = 5 Hz × 2 m = 10 m/s. Distractors come from adding or subtracting the values instead of multiplying.
8Which is a renewable resource?
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Answer: solar energy
Sunlight is continuously available.
9Which organelle is the primary site of aerobic energy production in a cell?
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Answer: Mitochondrion
Mitochondria convert glucose and oxygen into usable chemical energy (ATP) through cellular respiration. Chloroplasts perform photosynthesis, the Golgi apparatus packages proteins, and vacuoles store materials.
10What causes the seasons on Earth?
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Answer: Earth's tilted axis as it orbits the Sun
Tilt changes how directly sunlight hits each hemisphere.