ASVAB General Science Practice Test 2

Answer: B

Correct answer: Meiosis. Meiosis has two rounds of division after a single round of DNA copying, so one diploid cell yields four haploid cells, each with one set of chromosomes. It also shuffles chromosomes and allows crossing over, which makes each gamete genetically unique. Mitosis is the tempting distractor because it is also cell division, but it makes two cells identical to the parent cell, as needed for growth and tissue repair.

• A: Mitosis usually preserves chromosome set rather than creating haploid gametes.
• B (correct): Meiosis reduces chromosome sets during formation of reproductive cells.
• C: Photosynthesis captures light energy, not chromosome reduction.
• D: Osmosis is water movement across a semipermeable membrane.

Answer: B

Correct answer: condensation. When water vapor cools, its molecules slow down and cling together into liquid droplets. This is how clouds, fog and dew form, and it releases the energy absorbed during evaporation. Evaporation is the reverse process, liquid becoming vapor. A cold glass on a humid day shows condensation: droplets appear on the outside because vapor in the air cools against the glass, not because water leaks through.

• A: Evaporation converts liquid water into vapor.
• B (correct): Condensation converts vapor to liquid droplets, an important cloud-forming process.
• C: Infiltration moves water into soil or rock.
• D: Runoff moves water over land.

Answer: C

Correct answer: Meteor. The terms track the object's location: a meteoroid is a small rock in space, a meteor is the glowing streak when it rushes into the atmosphere and heats the air around it, and a meteorite is any piece that survives to land on the ground. A memory hook is that the meteorite reaches the earth's surface, ending in "-ite" like many rock names. Comets are icy bodies in orbit.

• A: Meteorite is a fragment that reaches the ground.
• B: An asteroid belt is a population in space, not a light streak.
• C (correct): Meteor refers to the visible atmospheric phenomenon.
• D: A comet is an icy object orbiting the Sun.

Answer: C

Correct answer: It turns red. Litmus is an indicator dye that changes color with acidity: acids turn blue litmus red, and bases turn red litmus blue. Lemon juice contains citric acid and has a pH of about 2, so the blue paper turns red. A common memory aid is BRA: blue to red means acid. Other indicators use colors such as green or pink, but litmus shows only red or blue.

• A: Blue litmus stays blue only in a neutral or basic liquid, and lemon juice is acidic.
• B: Green is the neutral color on universal indicator, not a litmus result.
• C (correct): Lemon juice contains citric acid, and acids turn blue litmus red.
• D: Pink is the color phenolphthalein shows in a fairly basic solution, not a litmus color for acid.

Answer: C

Correct answer: Twenty thousand square centimeters. 1 $m^2$ = ${\left(100cm\right)}^2$ = 10,000 cm²; 2 $m^2$ = 20,000 cm².

• A: 2,000 is ten times too small.
• B: 200 incorrectly applies a single length conversion without squaring.
• C (correct): Correct: 2 × 10,000 = 20,000 cm².
• D: 2,000,000 applies an additional factor of 100.

Answer: C

Correct answer: 130. Population size changes through four flows. Births and immigration add individuals, while deaths and emigration remove them. Write the change as births plus immigrants minus deaths minus emigrants, then add it to the starting size. Here the gains are 40 and the losses are 30, for a net gain of 10. The tempting mistakes come from adding only the gains or forgetting one of the losses, so list all four terms before calculating.

• A: This includes additions but ignores losses.
• B: This fails to subtract some departures.
• C (correct): 120 + 30 + 10 − 25 − 5 = 130.
• D: This misses some population flows.

Answer: A

Correct answer: Return excess tissue fluid toward the bloodstream. Blood pressure pushes some plasma out of capillaries into the spaces around cells, and not all of it seeps back. Lymphatic vessels collect this extra fluid, now called lymph, and carry it through lymph nodes, where immune cells screen it, before returning it to veins near the heart. If drainage fails, fluid builds up and causes swelling called edema. Lymphatics also absorb dietary fats from the small intestine.

• A (correct): Lymphatic vessels collect interstitial fluid and convey it back into circulation.
• B: Airways conduct air, not lymphatic vessels.
• C: Red blood cells develop mainly in bone marrow.
• D: The heart and arteries perform this blood-flow function.

Answer: D

Correct answer: 40 N. Weight is the force of gravity on a mass, found with W = mg: mass in kilograms times gravitational acceleration in meters per second squared. Multiplying kg by m/s² gives kg·m/s², which is the newton, so the units confirm the setup. Here 4 kg × 10 m/s² gives 40 N. The common slip is to report the mass, 4, as the weight; kilograms measure matter, while newtons measure force.

• A: Division by g would not give weight.
• B: Four is mass in kilograms, not force in newtons.
• C: Adding 4 and 10 is dimensionally wrong.
• D (correct): W=mg=4×10=40 N.

Answer: D

Correct answer: The rock contains carbonate minerals that release carbon dioxide. Fizzing on a rock is the classic sign of carbonate minerals, such as those in limestone or marble. The acid reacts with the carbonate to produce carbon dioxide gas.

• A: A rock at ordinary temperature cannot boil the acid; the bubbles come from a new gas.
• B: Gold does not react with dilute acid, and acid reactions with rock do not release oxygen.
• C: Silver is a less reactive metal that does not release hydrogen from dilute acid.
• D (correct): Acids react with carbonates to form carbon dioxide gas, water and a salt, which causes the fizzing.

Answer: D

Correct answer: His daughters, not his sons. A father has one X and one Y chromosome, and each sperm carries one or the other. A daughter must receive his X to be XX, while a son must receive his Y to be XY. So every daughter gets his X-linked variant, and no son gets it from him. The common error is assuming all children have equal odds, as with autosomal genes; an X-linked variant never passes directly from father to son.

• A: A son ordinarily receives the father’s Y rather than X.
• B: Daughters normally receive a paternal X.
• C: Paternal X inheritance differs from autosomal patterns.
• D (correct): Fathers generally transmit X to daughters and Y to sons.

Answer: A

Correct answer: Spinal cord. A withdrawal reflex uses a short pathway called a reflex arc: a sensory neuron carries the pain signal to the spinal cord, an interneuron relays it, and a motor neuron makes the muscle contract. Because the signal does not have to travel to the brain and back, the response is very fast. The brain still receives the information, which is why you feel pain a moment after your hand has already moved.

• A (correct): A reflex circuit in the spinal cord can activate motor neurons before full conscious awareness.
• B: It absorbs nutrients, not immediate neural reflex signals.
• C: The liver handles metabolism and bile production.
• D: It pumps blood, but is not the processing center of a withdrawal reflex.

Answer: A

Correct answer: Chloroplasts store light energy in carbohydrate, and mitochondria make ATP through respiration. Photosynthesis and respiration are distinct processes that may coexist in a green plant cell.

• A (correct): Photosynthesis and cellular respiration are distinct processes that both run in a green plant cell.
• B: Mitochondria work alongside chloroplasts in green plant cells and carry out respiration day and night.
• C: Carbon dioxide provides carbon in photosynthesis.
• D: Plant cells carry out cellular respiration, and in the dark it is their main source of ATP.

Answer: A

Correct answer: 25 m/s. One peak every 0.02 s at a fixed point means one full cycle passes each 0.02 s, so that is the period. Frequency is the reciprocal,

Wave speed then follows from v = fλ, 50 × 0.5. An equivalent shortcut is v = λ/T, since the wave moves one wavelength each period. Multiplying period by wavelength is the trap, and its units, m·s, are not a speed.

• A (correct): The period is 0.02 s, so f = 50 Hz and v = 50 × 0.5 = 25 $\frac{\mathrm{m}}{\mathrm{s}}$.
• B: Ten meters per second would be correct for a lower frequency of 20 Hz.
• C: 0.01 is a product of period and wavelength rather than speed.
• D: Two hundred fifty meters per second assumes a tenfold shorter period.

Answer: B

Correct answer: 50 J. Each transfer passes along only about 10% of the energy, because most of the rest is used for life processes and lost as heat. Multiply by 0.1 once per step: 50,000 J becomes 5,000 J, then 500 J, then 50 J after three transfers. Count the arrows carefully, because stopping one step early is the usual error. This steep loss explains why food chains rarely have more than four or five levels and why top predators are relatively few.

• A: 5,000 J corresponds to one transfer.
• B (correct): 50,000 × $0.1^3$ = 50 J.
• C: 500 J corresponds to two transfers.
• D: Energy transfers are not zero, and matter conservation does not imply no trophic transfer.

Answer: A

Correct answer: 8 protons and 10 neutrons. The nucleus holds only protons and neutrons, and gaining or losing electrons never changes it. Oxygen's atomic number fixes 8 protons, and mass number 18 leaves 18 minus 8, or 10, neutrons. The 2− charge tells you only that the ion has two more electrons than protons, 10 versus 8. The tempting mistake is to read the electron count of 10 as the proton count, which would turn the nucleus into neon's.

• A (correct): Oxygen has eight protons; neutron count is 18 − 8 = ten. The extra electrons produce the negative charge.
• B: Ten is electron count, not oxygen’s proton count.
• C: Eight protons plus eight neutrons would give mass number 16, not 18.
• D: This treats electrons as protons and produces the wrong nucleus.