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**ASVAB GENERAL SCIENCE – 150+ PRACTICE
QUESTIONS WITH ANSWERS & RATIONALES
(SUMMER 2025 EDITION)**
# TABLE OF CONTENTS
| Section | Topic | Questions |
|---------|-------|-----------|
| 1 | Biology (Cells, Human Body, Life Sciences) | 1–35 |
| 2 | Chemistry (Matter, Reactions, Periodic Table) | 36–65 |
| 3 | Physics (Forces, Motion, Energy, Electricity) | 66–95 |
| 4 | Earth & Space Science (Geology, Astronomy, Weather) | 96–120 |
| 5 | Health & Nutrition (Human Health, Disease Prevention) | 121–140 |
| 6 | Environmental Science & Ecology | 141–150 |
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# SECTION 1: BIOLOGY (Cells, Human Body, Life Sciences) –
Questions 1–35
**1.** The basic structural and functional unit of all living organisms is
the:
A) Nucleus
B) Organ
C) Cell
D) Tissue
**Correct Answer:** C – Cell
**Rationale:** The cell is the smallest unit of life. All living things are
composed of cells, and cells carry out the essential processes of life
(metabolism, growth, reproduction).
**2.** Which organelle is known as the "powerhouse of the cell"
because it produces energy (ATP)?
A) Ribosome
B) Mitochondrion
C) Nucleus
D) Golgi apparatus
**Correct Answer:** B – Mitochondrion
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**Rationale:** Mitochondria convert glucose and oxygen into ATP
through cellular respiration. Ribosomes synthesize proteins; the nucleus
contains DNA; the Golgi apparatus modifies and packages proteins.
**3.** The process by which plants convert sunlight, carbon dioxide,
and water into glucose and oxygen is called:
A) Cellular respiration
B) Photosynthesis
C) Fermentation
D) Transpiration
**Correct Answer:** B – Photosynthesis
**Rationale:** Photosynthesis occurs in chloroplasts. The equation is
6CO₂ + 6H₂O + sunlight → C₆H₁₂O₆ + 6O₂. Cellular respiration is the
opposite process.
**4.** Which of the following is a function of the circulatory system?
A) Breaking down food
B) Transporting oxygen and nutrients to cells
C) Producing hormones
D) Filtering waste from blood
**Correct Answer:** B – Transporting oxygen and nutrients to cells
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**Rationale:** The circulatory system (heart, blood vessels, blood)
transports oxygen, nutrients, hormones, and waste products. The kidneys
filter waste; the digestive system breaks down food.
**5.** The largest organ in the human body is the:
A) Heart
B) Liver
C) Skin
D) Lungs
**Correct Answer:** C – Skin
**Rationale:** The skin is the largest organ by surface area and weight
(about 15-20% of body weight). It provides protection, temperature
regulation, and sensation.
**6.** Which blood cells are primarily responsible for fighting
infection?
A) Red blood cells
B) Platelets
C) White blood cells (leukocytes)
D) Plasma
**Correct Answer:** C – White blood cells (leukocytes)
**ASVAB GENERAL SCIENCE – 150+ PRACTICE
QUESTIONS WITH ANSWERS & RATIONALES
(SUMMER 2025 EDITION)**
# TABLE OF CONTENTS
| Section | Topic | Questions |
|---------|-------|-----------|
| 1 | Biology (Cells, Human Body, Life Sciences) | 1–35 |
| 2 | Chemistry (Matter, Reactions, Periodic Table) | 36–65 |
| 3 | Physics (Forces, Motion, Energy, Electricity) | 66–95 |
| 4 | Earth & Space Science (Geology, Astronomy, Weather) | 96–120 |
| 5 | Health & Nutrition (Human Health, Disease Prevention) | 121–140 |
| 6 | Environmental Science & Ecology | 141–150 |
,2|Page
# SECTION 1: BIOLOGY (Cells, Human Body, Life Sciences) –
Questions 1–35
**1.** The basic structural and functional unit of all living organisms is
the:
A) Nucleus
B) Organ
C) Cell
D) Tissue
**Correct Answer:** C – Cell
**Rationale:** The cell is the smallest unit of life. All living things are
composed of cells, and cells carry out the essential processes of life
(metabolism, growth, reproduction).
**2.** Which organelle is known as the "powerhouse of the cell"
because it produces energy (ATP)?
A) Ribosome
B) Mitochondrion
C) Nucleus
D) Golgi apparatus
**Correct Answer:** B – Mitochondrion
,3|Page
**Rationale:** Mitochondria convert glucose and oxygen into ATP
through cellular respiration. Ribosomes synthesize proteins; the nucleus
contains DNA; the Golgi apparatus modifies and packages proteins.
**3.** The process by which plants convert sunlight, carbon dioxide,
and water into glucose and oxygen is called:
A) Cellular respiration
B) Photosynthesis
C) Fermentation
D) Transpiration
**Correct Answer:** B – Photosynthesis
**Rationale:** Photosynthesis occurs in chloroplasts. The equation is
6CO₂ + 6H₂O + sunlight → C₆H₁₂O₆ + 6O₂. Cellular respiration is the
opposite process.
**4.** Which of the following is a function of the circulatory system?
A) Breaking down food
B) Transporting oxygen and nutrients to cells
C) Producing hormones
D) Filtering waste from blood
**Correct Answer:** B – Transporting oxygen and nutrients to cells
, 4|Page
**Rationale:** The circulatory system (heart, blood vessels, blood)
transports oxygen, nutrients, hormones, and waste products. The kidneys
filter waste; the digestive system breaks down food.
**5.** The largest organ in the human body is the:
A) Heart
B) Liver
C) Skin
D) Lungs
**Correct Answer:** C – Skin
**Rationale:** The skin is the largest organ by surface area and weight
(about 15-20% of body weight). It provides protection, temperature
regulation, and sensation.
**6.** Which blood cells are primarily responsible for fighting
infection?
A) Red blood cells
B) Platelets
C) White blood cells (leukocytes)
D) Plasma
**Correct Answer:** C – White blood cells (leukocytes)
