ASVAB MEPS Practice Exam
130 Questions • Complete Answer Key • Detailed Rationales
Table of Contents
Section Questions Page
General Science (GS) 1–20 1
Arithmetic Reasoning (AR) 21–40 3
Word Knowledge (WK) 41–55 5
Paragraph Comprehension (PC) 56–70 6
Mathematics Knowledge (MK) 71–90 8
Electronics Information (EI) 91–105 10
Auto & Shop Information (AS/SI) 106–115 12
Mechanical Comprehension (MC) 116–125 13
Assembling Objects (AO) 126–130 14
GENERAL SCIENCE (GS)
Questions 1–20
1. Which of the following is the smallest unit of matter that retains the properties of an element?
A. Atom
B. Molecule
C. Proton
D. Electron
🔵 A. Atom
Rationale: An atom is the smallest unit of matter that retains the chemical properties of an element. Molecules are
combinations of atoms. Protons and electrons are subatomic particles that do not retain elemental properties on their
own.
2. The process by which plants convert light energy into chemical energy is called:
A. Cellular respiration
, B. Fermentation
C. Photosynthesis
D. Transpiration
🔵 C. Photosynthesis
Rationale: Photosynthesis is the process by which green plants and some other organisms use sunlight to synthesize
foods from carbon dioxide and water. Cellular respiration is the opposite process, releasing energy from food.
3. Which blood type is known as the universal donor?
A. Type A
B. Type B
C. Type AB
D. Type O
🔵 D. Type O
Rationale: Type O blood lacks A and B antigens on the surface of red blood cells, making it safe to transfuse to any
blood type in emergency situations. Type AB is the universal recipient.
4. The chemical symbol for gold is:
A. Go
B. Gd
C. Au
D. Ag
🔵 C. Au
Rationale: The chemical symbol Au comes from the Latin word aurum, meaning gold. Ag is silver, Gd is gadolinium, and
Go is not a valid chemical symbol.
5. Which of the following is a function of the skeletal system?
A. Producing hormones
B. Pumping blood
C. Protecting internal organs
D. Digesting food
🔵 C. Protecting internal organs
Rationale: The skeletal system provides structural support, protects vital organs (e.g., the skull protects the brain, the rib
cage protects the heart and lungs), produces blood cells, and stores minerals.
6. Water boils at which temperature at standard atmospheric pressure?
A. 100°C
B. 212°C
C. 32°F
, D. 0°C
🔵 A. 100°C
Rationale: Water boils at 100°C (212°F) at standard atmospheric pressure (1 atm). 32°F is the freezing point of water,
and 0°C is also the freezing point.
7. Any astronomical body that revolves around a larger body is called a:
A. Nova
B. Comet
C. Satellite
D. Asteroid
E. Meteoroid
🔵 C. Satellite
Rationale: A satellite is any object that orbits a larger body. This includes natural satellites like the Moon and artificial
satellites launched by humans. Novas are exploding stars, comets are icy bodies, asteroids are rocky bodies, and
meteoroids are small particles in space.
8. Which organ is responsible for filtering waste from the blood and producing urine?
A. Liver
B. Kidney
C. Heart
D. Lung
🔵 B. Kidney
Rationale: The kidneys filter waste products from the blood, regulate fluid balance, and produce urine. The liver
processes toxins, the heart pumps blood, and the lungs facilitate gas exchange.
9. The pH scale measures:
A. Temperature
B. Acidity or alkalinity
C. Pressure
D. Density
🔵 B. Acidity or alkalinity
Rationale: The pH scale ranges from 0 to 14 and measures the concentration of hydrogen ions in a solution. A pH of 7
is neutral, below 7 is acidic, and above 7 is basic (alkaline).
10. Which of the following is NOT a renewable energy source?
A. Solar power
B. Wind power
C. Nuclear power
, D. Hydroelectric power
🔵 C. Nuclear power
Rationale: Nuclear power relies on uranium, a finite resource, making it non-renewable. Solar, wind, and hydroelectric
power are renewable because they are continuously replenished by natural processes.
11. The human heart has how many chambers?
A. 2
B. 3
C. 4
D. 5
🔵 C. 4
Rationale: The human heart has four chambers: two atria (upper chambers) and two ventricles (lower chambers). This
structure allows for efficient separation of oxygenated and deoxygenated blood.
12. Which gas makes up the majority of Earth's atmosphere?
A. Oxygen
B. Carbon dioxide
C. Nitrogen
D. Argon
🔵 C. Nitrogen
Rationale: Nitrogen makes up approximately 78% of Earth's atmosphere. Oxygen comprises about 21%, with trace
gases making up the remainder.
13. If you place bean seeds between moist paper towels and watch the stem and leaves appear, you will see a
demonstration of:
A. Transpiration
B. Germination
C. Fertilization
D. Pollination
🔵 B. Germination
Rationale: Germination is the process by which a seed develops into a new plant. The appearance of a stem and leaves
from a seed is a clear demonstration of germination.
14. Which of the following is an example of a physical change?
A. Rusting iron
B. Burning wood
C. Melting ice
D. Digesting food
130 Questions • Complete Answer Key • Detailed Rationales
Table of Contents
Section Questions Page
General Science (GS) 1–20 1
Arithmetic Reasoning (AR) 21–40 3
Word Knowledge (WK) 41–55 5
Paragraph Comprehension (PC) 56–70 6
Mathematics Knowledge (MK) 71–90 8
Electronics Information (EI) 91–105 10
Auto & Shop Information (AS/SI) 106–115 12
Mechanical Comprehension (MC) 116–125 13
Assembling Objects (AO) 126–130 14
GENERAL SCIENCE (GS)
Questions 1–20
1. Which of the following is the smallest unit of matter that retains the properties of an element?
A. Atom
B. Molecule
C. Proton
D. Electron
🔵 A. Atom
Rationale: An atom is the smallest unit of matter that retains the chemical properties of an element. Molecules are
combinations of atoms. Protons and electrons are subatomic particles that do not retain elemental properties on their
own.
2. The process by which plants convert light energy into chemical energy is called:
A. Cellular respiration
, B. Fermentation
C. Photosynthesis
D. Transpiration
🔵 C. Photosynthesis
Rationale: Photosynthesis is the process by which green plants and some other organisms use sunlight to synthesize
foods from carbon dioxide and water. Cellular respiration is the opposite process, releasing energy from food.
3. Which blood type is known as the universal donor?
A. Type A
B. Type B
C. Type AB
D. Type O
🔵 D. Type O
Rationale: Type O blood lacks A and B antigens on the surface of red blood cells, making it safe to transfuse to any
blood type in emergency situations. Type AB is the universal recipient.
4. The chemical symbol for gold is:
A. Go
B. Gd
C. Au
D. Ag
🔵 C. Au
Rationale: The chemical symbol Au comes from the Latin word aurum, meaning gold. Ag is silver, Gd is gadolinium, and
Go is not a valid chemical symbol.
5. Which of the following is a function of the skeletal system?
A. Producing hormones
B. Pumping blood
C. Protecting internal organs
D. Digesting food
🔵 C. Protecting internal organs
Rationale: The skeletal system provides structural support, protects vital organs (e.g., the skull protects the brain, the rib
cage protects the heart and lungs), produces blood cells, and stores minerals.
6. Water boils at which temperature at standard atmospheric pressure?
A. 100°C
B. 212°C
C. 32°F
, D. 0°C
🔵 A. 100°C
Rationale: Water boils at 100°C (212°F) at standard atmospheric pressure (1 atm). 32°F is the freezing point of water,
and 0°C is also the freezing point.
7. Any astronomical body that revolves around a larger body is called a:
A. Nova
B. Comet
C. Satellite
D. Asteroid
E. Meteoroid
🔵 C. Satellite
Rationale: A satellite is any object that orbits a larger body. This includes natural satellites like the Moon and artificial
satellites launched by humans. Novas are exploding stars, comets are icy bodies, asteroids are rocky bodies, and
meteoroids are small particles in space.
8. Which organ is responsible for filtering waste from the blood and producing urine?
A. Liver
B. Kidney
C. Heart
D. Lung
🔵 B. Kidney
Rationale: The kidneys filter waste products from the blood, regulate fluid balance, and produce urine. The liver
processes toxins, the heart pumps blood, and the lungs facilitate gas exchange.
9. The pH scale measures:
A. Temperature
B. Acidity or alkalinity
C. Pressure
D. Density
🔵 B. Acidity or alkalinity
Rationale: The pH scale ranges from 0 to 14 and measures the concentration of hydrogen ions in a solution. A pH of 7
is neutral, below 7 is acidic, and above 7 is basic (alkaline).
10. Which of the following is NOT a renewable energy source?
A. Solar power
B. Wind power
C. Nuclear power
, D. Hydroelectric power
🔵 C. Nuclear power
Rationale: Nuclear power relies on uranium, a finite resource, making it non-renewable. Solar, wind, and hydroelectric
power are renewable because they are continuously replenished by natural processes.
11. The human heart has how many chambers?
A. 2
B. 3
C. 4
D. 5
🔵 C. 4
Rationale: The human heart has four chambers: two atria (upper chambers) and two ventricles (lower chambers). This
structure allows for efficient separation of oxygenated and deoxygenated blood.
12. Which gas makes up the majority of Earth's atmosphere?
A. Oxygen
B. Carbon dioxide
C. Nitrogen
D. Argon
🔵 C. Nitrogen
Rationale: Nitrogen makes up approximately 78% of Earth's atmosphere. Oxygen comprises about 21%, with trace
gases making up the remainder.
13. If you place bean seeds between moist paper towels and watch the stem and leaves appear, you will see a
demonstration of:
A. Transpiration
B. Germination
C. Fertilization
D. Pollination
🔵 B. Germination
Rationale: Germination is the process by which a seed develops into a new plant. The appearance of a stem and leaves
from a seed is a clear demonstration of germination.
14. Which of the following is an example of a physical change?
A. Rusting iron
B. Burning wood
C. Melting ice
D. Digesting food
