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WAEC Biology: practice questions.
12 free questions with answers and explanations, plus the topics to revise.
Below are free WAEC Biology practice questions with answers and explanations. They are original eZine questions, written and reviewed by teachers in the style of the WAEC WASSCE; we do not publish past questions. eZine's published WAEC Biology bank holds 393 questions across 54 topics (counted 29 October 2026); the largest topics are Basic Ecological Concepts, Classification of Living Organisms, Nutrition: Plants.
eZine's WAEC subject mock uses 50 questions in 60 minutes estimated. WAEC sets the objective paper's length per subject and publishes it in each subject's syllabus; eZine holds no WAEC paper figures yet, so this is a practice default.
WAEC Biology practice questions
Choose an option to check it, or open the answer. Each is an eZine practice question (original, teacher-reviewed).
Question 1 · Adaptation and Evolution
The forelimbs of a human, a bat and a whale have the same basic arrangement of bones but are used for different functions. Such structures are described as
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Answer: D. homologous structures
Homologous structures share the same basic structure and origin but are modified for different functions, which is evidence of descent from a common ancestor. Analogous structures (for example the wing of a bird and of a butterfly) do the same job but have different structures and origins; vestigial structures are reduced and have little or no function.
eZine practice question (original, teacher-reviewed)
Question 2 · Introduction to Bioethics
A pharmaceutical company wants to test a new antimalarial drug on volunteers in Kaduna. Which action is MOST important ethically?
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Answer: A. Obtaining informed consent from each volunteer after explaining the risks
Informed, voluntary consent is the core principle of ethical research on humans. Hiding side effects removes informed consent; using people who cannot refuse is coercion; hiding failed results is dishonest and endangers future patients.
eZine practice question (original, teacher-reviewed)
Question 3 · Microscopy and Staining Techniques
When preparing a temporary mount of onion epidermis, a cover slip is lowered at an angle using a mounted needle. This is done to
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Answer: C. avoid trapping air bubbles under the cover slip
Lowering slowly at an angle pushes air out ahead of the liquid. Air bubbles look like dark-edged circles and hide cells. The technique does not stain, cut or magnify.
eZine practice question (original, teacher-reviewed)
Question 4 · Conservation
Which practice in a hostel helps to prevent the breeding of houseflies?
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Answer: D. Covering refuse bins and disposing of refuse regularly
Flies breed in uncovered decaying refuse, so covering and regular disposal stops breeding. Uncovered food attracts flies; stagnant water breeds mosquitoes; piled refuse provides breeding sites.
eZine practice question (original, teacher-reviewed)
Question 5 · Conservation of Natural Resources
What is the main purpose of a protected wildlife area such as Yankari National Park in Bauchi State?
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Answer: B. To protect wild animals, plants and their habitats
National parks and game reserves conserve wildlife and their natural habitats, for example by banning hunting and clearing. Farming, logging and dumping all destroy the habitats such areas are set up to protect.
eZine practice question (original, teacher-reviewed)
Question 6 · Reproductive System - Plants
In a flowering plant such as the hibiscus, pollen grains are produced in the
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Answer: A. anther
The anther, at the tip of the filament in the stamen, contains pollen sacs in which pollen grains are produced. The stigma receives pollen, the ovary contains the ovules, and the filament only supports the anther.
eZine practice question (original, teacher-reviewed)
Question 7 · Science in Media and Misinformation
A WhatsApp message claims that drinking salt water cures Ebola. The best FIRST step to check this claim is to
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Answer: B. verify it from an official source such as the NCDC or WHO and look for published evidence
Claims should be checked against credible sources and evidence. Forwarding spreads misinformation; self-testing is dangerous (excess salt can harm, as happened in 2014); popularity is not evidence.
eZine practice question (original, teacher-reviewed)
Question 8 · Pollution
Which measure would best reduce noise pollution from generators in a residential area of Lagos?
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Answer: D. Housing generators in soundproof enclosures and enforcing permitted hours
Soundproofing and regulating hours reduce noise at source. Burning refuse adds air pollution; more generators add more noise; insecticide has nothing to do with noise.
eZine practice question (original, teacher-reviewed)
Question 9 · Homeostasis Organs
After playing football for two hours in the sun without drinking water, a student's pituitary gland releases more antidiuretic hormone (ADH). What is the effect on the kidneys?
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Answer: B. More water is reabsorbed from the distal tubules and collecting ducts, so a small volume of concentrated urine is produced
ADH makes the walls of the distal convoluted tubules and collecting ducts more permeable to water, so more water is reabsorbed into the blood and a small volume of concentrated urine is passed. Less ADH gives the opposite. ADH does not affect glucose reabsorption and does not stop filtration.
eZine practice question (original, teacher-reviewed)
Question 10 · Types of Nutrition: Heterotrophic Nutrition
The dental formula of a dog is i 3/3, c 1/1, pm 4/4, m 2/3. The total number of teeth in the dog is
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Answer: D. 42
One side: upper 3+1+4+2 = 10, lower 3+1+4+3 = 11, total 21. Both sides: 21 × 2 = 42. 21 counts only one side; 20 and 40 wrongly treat the lower molars as 2.
eZine practice question (original, teacher-reviewed)
Question 11 · Excretory System
The main nitrogenous waste product removed in the urine of mammals is
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Answer: D. urea
In mammals, the liver converts excess amino acids by deamination into urea, which the kidneys excrete in urine. Ammonia is the main nitrogenous waste of many aquatic animals such as most bony fish; uric acid is excreted by birds, reptiles and insects; carbon dioxide is not a nitrogenous waste.
eZine practice question (original, teacher-reviewed)
Question 12 · Cell Structure and Functions
In which organelle of a cell does aerobic respiration release most of the cell's energy?
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Answer: D. Mitochondrion
The mitochondrion is the site of the Krebs cycle and the electron transport chain, where most of the ATP of aerobic respiration is produced. Ribosomes make proteins, the Golgi apparatus packages and secretes materials, and chloroplasts carry out photosynthesis (they trap energy rather than release it).
eZine practice question (original, teacher-reviewed)
Want more Biology questions, timed, with every mistake explained?
Practise free on eZine →Topics in eZine's WAEC Biology practice bank
- Basic Ecological Concepts (31)
- Classification of Living Organisms (27)
- Nutrition: Plants (18)
- Cell Structure and Functions (17)
- Reproductive System - Plants (16)
- Nervous Systems (15)
- Types of Nutrition: Heterotrophic Nutrition (14)
- Variation in Populations and Heredity (14)
- Supporting Systems: Animals (13)
- Animal Nutrition: Balanced Diet (12)
- The Circulatory System (11)
- Cellular Respiration (10)
- Conservation of Natural Resources (10)
- Endocrine System-Animals (10)
- Excretory System (10)
- Homeostasis Organs (10)
- Transport System (10)
- Digestive System (8)
- Micro-organisms Around Us (8)
- Feeding Relationships Among Organisms (7)
- Microscopy and Staining Techniques (7)
- Respiratory System - Animals (7)
- Common Diseases and Mode of Transmission (6)
- Plants Hormones (6)
Published questions per topic, counted 29 October 2026. eZine does not reproduce WAEC's own Biology syllabus here; check the official syllabus with your school or at the WAEC website.