CLEP Practice Test

CLEP Biology is a College Board exam that people take to earn college credit without sitting a full course. This page gives you the verified exam facts, free practice sets grouped by topic, worked explanations for sample questions, and a study plan that uses these sets alongside the official College Board material.

CLEP Exam at a Glance

What the CLEP is and how it works

According to College Board, “The exam contains approximately 115 questions to be answered in 90 minutes. Some of these are pretest questions that will not be scored.”^[1]

The CLEP Biology exam is a College Board credit-by-examination test. A qualifying score can earn college credit. The ACE recommendation is 6 semester hours at a credit-granting score of 50 on the 20–80 scale. Whether your college accepts that score, and how much credit it gives, is decided by the college, so check its CLEP policy before you register.

The exam contains approximately 115 questions to be answered in 90 minutes. Some are pretest questions that are not scored, and you cannot tell which ones they are, so treat every item as if it counts.

You can test at a test center or by remote proctoring. Remote proctoring uses Proctortrack on a Windows PC with a human proctor, and it has the same timing, content, format and on-screen experience as a test center. The exam fee is $97, and remote proctoring adds $30. Exams are offered year-round on a flexible schedule.

If you need to retake, you must wait 3 months from the test date, and you pay for the retest yourself. Scores for exams taken on or after July 1, 2022 stay available for 10 years from the test date. Fees, policies and credit rules can change, so confirm them on the official College Board CLEP Biology page before you book.

CLEP content outline and where to practise each area

The content areas below are copied from the official CLEP content outline published by College Board, with the share of the exam each area carries. The right-hand column shows which of our practice sets covers it.

Worked examples: how to reason through CLEP questions

These are practice questions written for this site, not questions from the real exam. Each explanation shows why the right answer is right and why the others are wrong.

Example 1

Question: The regulation of blood calcium levels involves the parathyroid hormone (PTH), which raises calcium levels, and calcitonin, which lowers them. This is a primary example of:

1. A positive feedback loop
2. Antagonistic hormonal action
3. Gene amplification
4. Coenzyme activation

Answer: B. Antagonistic hormonal action

Explanation:

The answer is antagonistic hormonal action. Parathyroid hormone raises blood calcium and calcitonin lowers it, so the hormones push in opposite directions and hold the level steady. A positive feedback loop is wrong because it amplifies a change instead of correcting it, and this system pulls the level back toward its set range. Gene amplification is wrong because it describes making extra copies of a gene, which is not what these hormones do. Coenzyme activation is wrong because it concerns helper molecules for enzymes, not the balance between hormones. Rule to remember: when hormones with opposite effects control the same variable, think antagonistic action and negative feedback.

Example 2

Question: Which cellular structure is found in plant cells but not in animal cells?

1. Nucleus
2. Mitochondrion
3. Cell wall
4. Plasma membrane

Answer: C. Cell wall

Explanation:

The answer is the cell wall. It is a rigid outer layer that gives plant cells support and protection, and animal cells do not have one. The nucleus is wrong because plant and animal cells are both eukaryotic and both contain a nucleus. The mitochondrion is wrong because plant cells and animal cells both use mitochondria for cellular respiration. The plasma membrane is wrong because every cell has one, and in plants it sits just inside the wall. Rule to remember: when a question asks what is unique to plants, look for the cell wall, chloroplasts and the large central vacuole, not for structures that all eukaryotes share.

Example 3

Question: During which phase of mitosis do chromosomes align at the cell's equatorial plate (metaphase plate)?

1. Prophase
2. Metaphase
3. Anaphase
4. Telophase

Answer: B. Metaphase

Explanation:

The answer is metaphase. In metaphase, spindle fibers attached to the kinetochores move the chromosomes to the middle of the cell and line them up on the metaphase plate. Prophase is wrong because chromosomes condense and the spindle begins to form, but they have not yet lined up. Anaphase is wrong because the sister chromatids are pulled apart toward opposite ends of the cell. Telophase is wrong because the separated chromosomes have arrived at the poles and nuclei begin to re-form. Rule to remember: the phase names describe what the chromosomes are doing, so metaphase means middle, anaphase means apart.

How to use these practice tests

Start with the official College Board CLEP Biology page, so you know the content areas and the question format before you practise. Then take the practice set for each area, starting with the one you feel least sure about: Molecular and Cellular Biology, Organismal Biology and Physiology, and Ecology and Evolutionary Processes.

1. Answer a set without notes, then read the explanation for every miss and for every guess that happened to be right.
2. Keep a short list of the topics you missed, such as DNA replication, Mendelian inheritance or cellular respiration and photosynthesis, and use the focused sets to drill them.
3. Return to a set after a few days and see whether the same topics still trip you up.
4. Near test day, practise at the exam pace of approximately 115 questions in 90 minutes, so the timing feels familiar.

Our questions are written by us and are not real exam questions, so use them to find gaps and then fill those gaps from your textbook or course notes.

Sources & last verified

1. College Board — number of questions, time limit, exam fee, passing score (official source). “The exam contains approximately 115 questions to be answered in 90 minutes. Some of these are pretest questions that will not be scored.” Verified Oct 28, 2026.
2. College Board — exam fee (official source). “In addition to the CLEP exam fee, you'll be charged $30 for remote proctoring.” Verified Oct 26, 2026.
3. College Board — retake fee, retake policy (official source). “Any retest attempts for the same examination title must be funded directly by the test taker.” Verified Oct 26, 2026 · source checked Oct 26, 2026.
4. College Board — validity (official source). “CLEP scores for exams taken on or after July 1, 2022, will be available for 10 years from the test date.” Verified Oct 26, 2026 · source checked Oct 16, 2026.
5. College Board — delivery (official source). “Each CLEP exam taken with remote proctoring has the same timing, content, format, and on-screen experience as the test you would take at a CLEP…” Verified Oct 26, 2026.
6. College Board — testing window (official source). “CLEP exams are administered year-round on a flexible schedule.” Verified Oct 26, 2026 · source checked Oct 16, 2026.

How we verify: editorial & fact-checking policy. Report an error: contact us.