ASVAB General Science Practice Test

Chloroplasts contain chlorophyll, which captures light energy to make sugar from carbon dioxide and water. The nucleus holds the cell's DNA, and the vacuole mainly stores water and other substances.

Blood returns from the lungs to the left atrium, passes into the left ventricle, and the thick-walled left ventricle pumps it through the aorta to the body. The right ventricle pumps oxygen-poor blood to the lungs, not to the body.

The body needs vitamin C to build collagen, a protein that holds tissues together, so a long-term shortage leads to scurvy. A lack of vitamin D causes weak bones (rickets in children), and too little iron causes anemia.

The small intestine is lined with millions of tiny folds called villi that absorb most nutrients. The stomach breaks food down but absorbs little, and the large intestine mainly absorbs water.

Mushrooms and yeasts are fungi: they cannot make their own food and instead absorb nutrients from their surroundings. Unlike plants, they have no chlorophyll and do not carry out photosynthesis.

The troposphere is the lowest layer and holds nearly all of the atmosphere's water vapor, so clouds, rain and storms form there. The stratosphere above it contains the ozone layer.

Igneous rocks such as granite and basalt form from cooled molten rock. Sedimentary rock forms from layers of pressed sediment, and metamorphic rock forms when existing rock is changed by heat and pressure.

Earth's core is a dense ball of iron and nickel, with a liquid outer core and a solid inner core. Silicon and oxygen are the most common elements in the crust, not the core.

Resistance is measured in ohms (Ω). Volts measure voltage, amperes measure current and watts measure power; Ohm's law links them as voltage = current × resistance.

On the pH scale, 7 is neutral, values below 7 are acidic and values above 7 are basic. A pH of 2 is far below 7, so the solution is strongly acidic, like lemon juice or stomach acid.

Every atom of an element has the same number of protons, and that number is its atomic number. Protons plus neutrons give the mass number, which can differ between isotopes of the same element.

Sound is a vibration passed from particle to particle, and it moves fastest through solids such as steel, slower through liquids and slowest through gases. It cannot travel through a vacuum at all, because there are no particles to vibrate.

Newton's third law says that for every action there is an equal and opposite reaction: the engines push the gases down, and the gases push the rocket up. The first law describes inertia, an object's tendency to keep doing what it is doing.

Lightning and thunder happen at the same moment, but light reaches you almost instantly while sound covers only about a kilometer every three seconds. The delay grows the farther away the strike is.

Na comes from natrium, the Latin name for sodium. Nitrogen is N, nickel is Ni and neon is Ne.