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# GED® SCIENCE PRACTICE TEST
## COMPLETE QUESTION BANK (250+
QUESTIONS WITH PASSAGES, ANSWERS &
RATIONALES)
### 2026-2027 EDITION | BASED ON GED
TESTING SERVICE & OFFICIAL TEST
SPECIFICATIONS
## SECTION 1: LIFE SCIENCE: BIOLOGY & HUMAN SYSTEMS
### Questions 1-40
**Question 1**
What is the basic unit of life?
A) The atom
B) The cell
C) The molecule
D) The tissue
**Correct Answer: B**
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**Rationale:** The cell is the basic structural and functional unit of all living
organisms. All living things are composed of one or more cells . This is a
foundational concept in life science.
---
**Question 2**
Which organelle is responsible for cellular respiration and ATP production?
A) Nucleus
B) Ribosome
C) Mitochondrion
D) Golgi apparatus
**Correct Answer: C**
**Rationale:** Mitochondria are responsible for cellular respiration, producing
ATP (energy) through the breakdown of glucose. They are often called the
"powerhouses of the cell."
---
**Question 3**
What is the function of the nucleus in a cell?
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A) To produce energy
B) To control cell activities and store genetic material
C) To synthesize proteins
D) To package proteins for transport
**Correct Answer: B**
**Rationale:** The nucleus contains DNA and controls cellular activities. It is the
command center of the cell.
---
**Question 4**
What is photosynthesis?
A) The process of breaking down glucose to release energy
B) The process by which plants convert sunlight, water, and CO₂ into glucose and
oxygen
C) The process of cellular reproduction
D) The process of protein synthesis
**Correct Answer: B**
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**Rationale:** Photosynthesis is the process plants use to convert light energy into
chemical energy, producing glucose and oxygen from carbon dioxide and water.
This is the foundation of most food chains.
---
**Question 5**
What is the formula for photosynthesis?
A) C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O
B) 6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂
C) CO₂ + H₂O → C₆H₁₂O₆ + O₂
D) C₆H₁₂O₆ + O₂ → CO₂ + H₂O
**Correct Answer: B**
**Rationale:** The formula for photosynthesis is 6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂.
This shows the conversion of carbon dioxide and water into glucose and oxygen
using light energy.
---
**Question 6**
What is cellular respiration?
# GED® SCIENCE PRACTICE TEST
## COMPLETE QUESTION BANK (250+
QUESTIONS WITH PASSAGES, ANSWERS &
RATIONALES)
### 2026-2027 EDITION | BASED ON GED
TESTING SERVICE & OFFICIAL TEST
SPECIFICATIONS
## SECTION 1: LIFE SCIENCE: BIOLOGY & HUMAN SYSTEMS
### Questions 1-40
**Question 1**
What is the basic unit of life?
A) The atom
B) The cell
C) The molecule
D) The tissue
**Correct Answer: B**
,2|Page
**Rationale:** The cell is the basic structural and functional unit of all living
organisms. All living things are composed of one or more cells . This is a
foundational concept in life science.
---
**Question 2**
Which organelle is responsible for cellular respiration and ATP production?
A) Nucleus
B) Ribosome
C) Mitochondrion
D) Golgi apparatus
**Correct Answer: C**
**Rationale:** Mitochondria are responsible for cellular respiration, producing
ATP (energy) through the breakdown of glucose. They are often called the
"powerhouses of the cell."
---
**Question 3**
What is the function of the nucleus in a cell?
,3|Page
A) To produce energy
B) To control cell activities and store genetic material
C) To synthesize proteins
D) To package proteins for transport
**Correct Answer: B**
**Rationale:** The nucleus contains DNA and controls cellular activities. It is the
command center of the cell.
---
**Question 4**
What is photosynthesis?
A) The process of breaking down glucose to release energy
B) The process by which plants convert sunlight, water, and CO₂ into glucose and
oxygen
C) The process of cellular reproduction
D) The process of protein synthesis
**Correct Answer: B**
, 4|Page
**Rationale:** Photosynthesis is the process plants use to convert light energy into
chemical energy, producing glucose and oxygen from carbon dioxide and water.
This is the foundation of most food chains.
---
**Question 5**
What is the formula for photosynthesis?
A) C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O
B) 6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂
C) CO₂ + H₂O → C₆H₁₂O₆ + O₂
D) C₆H₁₂O₆ + O₂ → CO₂ + H₂O
**Correct Answer: B**
**Rationale:** The formula for photosynthesis is 6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂.
This shows the conversion of carbon dioxide and water into glucose and oxygen
using light energy.
---
**Question 6**
What is cellular respiration?
