IB Biology Practice Test 2026
AI-generated IB Biology practice sets for Cell Biology, Molecular Biology, Genetics, Ecology, with scoring and explanations. Start with 30 free question credits on signup.
About the IB Biology exam
The International Baccalaureate - Biology (IB Biology) is a ib diploma examination administered in International 🌍. It is designed to assess candidates' knowledge and proficiency across 6 key subject areas including Cell Biology, Molecular Biology, Genetics, Ecology. This exam is widely recognized as an essential benchmark for students and professionals.
Use short IB Biology practice sets to identify topics to revisit. Choose a subject and difficulty, answer questions, then review the explanations. New accounts get 30 question credits; further new questions use paid credits. Retaking previously seen questions is free.
Whether you're a first-time candidate or retaking the IB Biology to improve your score, InfinityMock helps you identify your strengths and weaknesses through detailed performance analytics. Our platform covers Cell Biology, Molecular Biology, Genetics, Ecology, Evolution, Human Physiology, with questions available at Easy, Medium, and Hard difficulty levels. Track your progress, review detailed explanations, and build the confidence you need to pass on exam day.
IB Biology — quick answers
What is the IB Biology?
The International Baccalaureate - Biology (IB Biology) is a ib diploma examination taken in International 🌍. It assesses 6 subject areas: Cell Biology, Molecular Biology, Genetics, Ecology, Evolution, Human Physiology.
Where can I find free IB Biology practice questions?
This page carries 8 free IB Biology practice questions, each with a worked explanation. No account is needed to read them. Sign up for 30 free question credits to continue with a subject practice set.
What subjects does the IB Biology cover?
Cell Biology, Molecular Biology, Genetics, Ecology, Evolution, Human Physiology. On InfinityMock you can practise a single subject or take a mixed test across all 6.
How much does InfinityMock cost?
New accounts get 30 question credits free. After that, 30 credits cost $1 and 150 credits cost $5. One credit covers one new question; re-attempting a question you have already seen is always free.
IB Biology at a glance
| Exam | International Baccalaureate - Biology (IB Biology) |
|---|---|
| Category | IB Diploma |
| Country / region | International 🌍 |
| Subjects covered | 6 — Cell Biology, Molecular Biology, Genetics, Ecology, Evolution, Human Physiology |
8 free IB Biology practice questions (2026)
Answer these first — no signup, no card. Every answer is explained. For more practice, sign up for 30 free question credits and choose a subject above.
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Which of the following processes does NOT directly involve the plasma membrane?
- Active transport
- Facilitated diffusion
- DNA replication
- Exocytosis
Show answer & explanation
Answer: C. DNA replication
DNA replication occurs within the nucleus, not at the plasma membrane.
Topic: Cell Biology · easy
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What is the primary function of the Golgi apparatus?
- Protein synthesis
- Lipid synthesis
- Protein modification and sorting
- Energy production
Show answer & explanation
Answer: C. Protein modification and sorting
The Golgi apparatus modifies, sorts, and packages proteins and lipids for transport to other organelles or secretion.
Topic: Cell Biology · easy
-
A cell with a high concentration of ribosomes is most likely specialized for:
- Energy storage
- Protein synthesis
- Lipid metabolism
- Waste disposal
Show answer & explanation
Answer: B. Protein synthesis
Ribosomes are the sites of protein synthesis, so a cell with many ribosomes will be actively producing proteins.
Topic: Cell Biology · easy
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Which of the following structures is NOT found in prokaryotic cells?
- Ribosomes
- Cell wall
- Nucleus
- Plasma membrane
Show answer & explanation
Answer: C. Nucleus
Prokaryotic cells lack a membrane-bound nucleus; their DNA is located in the nucleoid region.
Topic: Cell Biology · easy
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What is the role of cholesterol in animal cell membranes?
- To provide rigidity and stability to the membrane.
- To facilitate the transport of water molecules across the membrane.
- To attach the membrane to the cytoskeleton.
- To act as a receptor for hormones.
Show answer & explanation
Answer: A. To provide rigidity and stability to the membrane.
Cholesterol helps maintain membrane fluidity and stability by preventing phospholipids from packing too tightly at low temperatures and reducing fluidity at high temperatures.
Topic: Cell Biology · medium
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What is the primary function of lysosomes?
- Protein synthesis
- Intracellular digestion
- ATP production
- Cellular respiration
Show answer & explanation
Answer: B. Intracellular digestion
Lysosomes contain enzymes that break down cellular waste and debris through intracellular digestion.
Topic: Cell Biology · easy
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Which of the following statements best describes the fluid mosaic model of the cell membrane?
- A rigid structure composed of phospholipids and proteins.
- A dynamic structure with proteins embedded in a phospholipid bilayer.
- A static structure with proteins attached to the outer surface of the phospholipid bilayer.
- A single layer of phospholipids with proteins on the inner surface.
Show answer & explanation
Answer: B. A dynamic structure with proteins embedded in a phospholipid bilayer.
The fluid mosaic model describes the cell membrane as a dynamic structure where proteins are embedded within a fluid phospholipid bilayer, capable of lateral movement.
Topic: Cell Biology · medium
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Which of the following transport mechanisms requires energy input from the cell?
- Osmosis
- Facilitated diffusion
- Active transport
- Simple diffusion
Show answer & explanation
Answer: C. Active transport
Active transport moves substances against their concentration gradient, requiring energy, typically in the form of ATP.
Topic: Cell Biology · medium
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Why Practice with InfinityMock's IB Biology Mock Test?
- Fresh practice questions — Use credits for new questions; retake seen questions free
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- Independent practice — Use alongside current official IB Biology materials
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IB Biology Exam Subjects
Available practice subjects: Cell Biology, Molecular Biology, Genetics, Ecology, Evolution, Human Physiology. Select a subject for focused preparation. Coverage is not a guarantee of the complete official syllabus.
📖 IB Biology Study Guide
Read our comprehensive How to Pass the IB Biology in 2026 — Complete Study Guide for expert preparation tips, study plans, and strategies.
🔗 Related Exams
Students preparing for IB Biology also practice for:
Frequently Asked Questions
Is this IB Biology practice test free?
Yes! InfinityMock offers free IB Biology practice tests with 30 complimentary credits on signup. Each AI-generated question costs 1 credit, and previously seen questions are always free to retake.
How many IB Biology practice questions are available?
InfinityMock offers AI-generated practice in Cell Biology, Molecular Biology, Genetics, Ecology, Evolution, Human Physiology. One new question costs one credit; new accounts receive 30 free credits. These are independent practice questions, not official exam questions.
What subjects does the IB Biology practice test cover?
Our IB Biology mock test covers: Cell Biology, Molecular Biology, Genetics, Ecology, Evolution, Human Physiology. You can choose specific subjects or take a comprehensive test across all areas.
Does this reproduce the official IB Biology exam?
No. InfinityMock provides multiple-choice practice sets with explanations and progress tracking. Question types, timing, syllabus coverage, and scoring can differ from the official exam. Use your exam body's current syllabus and official practice materials alongside these sets.
How does the AI-powered IB Biology mock test work?
Simply select IB Biology from our exam list, choose your subject and difficulty level, and our AI instantly generates a custom mock test. After completing the test, you get detailed explanations, performance analytics, and a grade.
Can I retake the IB Biology practice test?
Absolutely! You can retake any IB Biology mock test as many times as you want. Previously seen questions are always free, so retakes cost no credits. You can also generate completely new questions each time.
What is the best way to prepare for the IB Biology?
The most effective strategy is consistent practice with realistic questions. Use InfinityMock to take regular mock tests, review your wrong answers with detailed explanations, track your progress over time, and focus on your weakest subjects. Start with easy difficulty and gradually increase to hard.
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