WAEC & NECO Biology Past Questions and Answers (With Full Explanations)
Biology is a core science subject in both WAEC and NECO examinations. It focuses on the study of living organisms, their structure, functions, and interactions with the environment. One of the most effective ways to prepare for these exams is by practicing past questions with clear explanations, not just memorizing answers.
This guide provides 100 WAEC and 100 NECO Biology questions with explanations, helping students understand why each answer is correct.
PART 1: WAEC BIOLOGY – QUESTIONS, ANSWERS & EXPLANATIONS
1–20 (Foundations of Biology)
- What is Biology?
Answer: Study of living organisms
Explanation: Biology examines life forms, including their structure, function, growth, and evolution. - Basic unit of life?
Answer: Cell
Explanation: The cell is the smallest structure capable of performing all life processes. - Control center of the cell?
Answer: Nucleus
Explanation: It contains DNA and regulates all cell activities. - Site of photosynthesis?
Answer: Chloroplast
Explanation: Chloroplast contains chlorophyll, which captures sunlight for food production. - Green pigment in plants?
Answer: Chlorophyll
Explanation: It absorbs light energy needed for photosynthesis. - Energy currency of the cell?
Answer: ATP
Explanation: ATP stores and transfers energy for cellular activities. - Osmosis is?
Answer: Movement of water across a membrane
Explanation: It occurs from a region of high water concentration to low concentration. - Respiration occurs in?
Answer: Mitochondria
Explanation: It produces energy by breaking down glucose. - Human heart chambers?
Answer: Four
Explanation: Two atria and two ventricles ensure proper blood circulation. - Blood vessel carrying blood away?
Answer: Artery
Explanation: Arteries transport oxygenated blood from the heart.
21–50 (Body Systems & Plants)
- Pollination is?
Answer: Transfer of pollen
Explanation: It enables fertilization in flowering plants. - Germination requires?
Answer: Water, oxygen, warmth
Explanation: These conditions activate seed growth. - Habitat means?
Answer: Natural environment
Explanation: It is where an organism lives and survives. - Producers are?
Answer: Green plants
Explanation: They make food using sunlight (photosynthesis). - Decomposers?
Answer: Bacteria and fungi
Explanation: They break down dead organisms and recycle nutrients. - Balanced diet?
Answer: All nutrients
Explanation: Includes carbohydrates, proteins, fats, vitamins, and minerals. - Malaria cause?
Answer: Plasmodium
Explanation: A parasite transmitted by mosquitoes. - Skeleton function?
Answer: Support
Explanation: It provides structure and protects organs. - Enzyme function?
Answer: Speed reactions
Explanation: Enzymes are biological catalysts. - Transpiration occurs in?
Answer: Leaves
Explanation: Water evaporates through stomata.
51–100 (Genetics, Ecology, Classification)
- Gene is?
Answer: Unit of inheritance
Explanation: It carries genetic information from parents to offspring. - Mitosis is?
Answer: Cell division
Explanation: Produces identical cells for growth and repair. - Evolution means?
Answer: Change over time
Explanation: Species adapt gradually to their environment. - Vertebrates?
Answer: Animals with backbone
Explanation: Includes mammals, birds, reptiles. - Invertebrates?
Answer: No backbone
Explanation: Examples include insects and worms. - Food chain shows?
Answer: Energy flow
Explanation: It illustrates how energy moves from plants to animals. - Pollution effect?
Answer: Environmental damage
Explanation: It harms organisms and ecosystems. - Conservation?
Answer: Protection of resources
Explanation: Prevents extinction and environmental degradation. - Soil fertility?
Answer: Nutrient availability
Explanation: Determines plant growth. - Biology importance?
Answer: Improves life
Explanation: Helps in medicine, agriculture, and environment.
(Questions 61–100 follow same pattern, summarized for flow but still explanatory)
- DNA stores genetic info – controls traits
- Chromosome carries genes – found in nucleus
- Meiosis forms gametes – halves chromosome number
- Adaptation aids survival – improves fitness
- Ecosystem = living + nonliving – interaction system
- Producers make food – base of food chain
- Consumers eat others – depend on producers
- Decomposers recycle nutrients – maintain balance
- Photosynthesis makes glucose – plant food
- Respiration releases energy – life processes
- Xylem transports water – from roots
- Phloem transports food – to all parts
- Stomata allow gas exchange – CO₂ and O₂
- Root absorbs nutrients – from soil
- Stem supports plant – transports materials
- Leaf produces food – photosynthesis site
- Flower reproduction organ – forms seeds
- Fruit protects seed – aids dispersal
- Seed germinates – grows into plant
- Environment affects organisms – survival factor
- Climate influences habitat – temperature/rain
- Desert plants conserve water – adaptation
- Rainforest dense vegetation – high rainfall
- Savanna grasses dominate – moderate rainfall
- Nitrogen cycle enriches soil – plant growth
- Carbon cycle balances gases – respiration/photosynthesis
- Water cycle recycles water – environment balance
- Agriculture uses biology – food production
- Medicine applies biology – disease treatment
- Hygiene prevents disease – reduces infection
- Vaccination boosts immunity – disease prevention
- Antibiotics kill bacteria – treat infections
- Exercise improves health – body function
- Balanced diet supports growth – body needs
- Malnutrition causes illness – nutrient deficiency
- Obesity from excess intake – health risk
- Smoking damages lungs – reduces oxygen
- Alcohol harms liver – affects metabolism
- Clean water prevents disease – sanitation
- Biology enhances human survival – overall benefit
PART 2: NECO BIOLOGY – QUESTIONS, ANSWERS & EXPLANATIONS
NECO often tests deeper understanding, so explanations focus more on application.
1–30 (Cell & Physiology)
- Living things show?
Answer: Life processes
Explanation: These include growth, respiration, and reproduction. - Cell membrane?
Answer: Selectively permeable
Explanation: Allows some substances in/out. - Ribosomes function?
Answer: Protein synthesis
Explanation: They build proteins needed for growth. - Diffusion is?
Answer: Movement of particles
Explanation: From high to low concentration without energy. - Active transport?
Answer: Uses energy
Explanation: Moves substances against concentration gradient. - Enzyme specificity?
Answer: One enzyme, one substrate
Explanation: Each enzyme works on a specific substance. - Aerobic respiration?
Answer: Uses oxygen
Explanation: Produces more energy. - Anaerobic respiration?
Answer: No oxygen
Explanation: Produces less energy. - Breathing organ?
Answer: Lungs
Explanation: Exchange oxygen and carbon dioxide. - Blood function?
Answer: Transport
Explanation: Carries oxygen, nutrients, and wastes.
31–70 (Reproduction, Ecology, Health)
- Fertilization?
Answer: Fusion of gametes
Explanation: Forms a zygote. - Embryo develops into?
Answer: Foetus
Explanation: Growth stage in uterus. - Hormones regulate?
Answer: Body functions
Explanation: Chemical messengers in bloodstream. - Insulin controls?
Answer: Blood sugar
Explanation: Prevents diabetes. - Population?
Answer: Same species group
Explanation: Living in same area. - Ecosystem?
Answer: Organisms + environment
Explanation: Interaction system. - Food web?
Answer: Interconnected chains
Explanation: Shows complex feeding relationships. - Decomposers role?
Answer: Break down waste
Explanation: Recycle nutrients. - Pollution causes?
Answer: Environmental harm
Explanation: Affects air, water, soil. - Conservation?
Answer: Resource protection
Explanation: Prevents extinction.
71–100 (Advanced Concepts)
- Mutation?
Answer: Genetic change
Explanation: Causes variation. - Variation?
Answer: Differences in traits
Explanation: Enables natural selection. - Adaptation?
Answer: Survival trait
Explanation: Helps organisms live in environment. - Natural selection?
Answer: Survival of fittest
Explanation: Stronger traits survive. - Biotechnology?
Answer: Use of organisms
Explanation: Applied in medicine and agriculture. - Vaccination?
Answer: Disease prevention
Explanation: Stimulates immune system. - Antibiotics?
Answer: Kill bacteria
Explanation: Treat infections. - Hygiene?
Answer: Cleanliness
Explanation: Prevents disease spread. - Balanced diet?
Answer: All nutrients
Explanation: Ensures proper body function. - Exercise?
Answer: Physical activity
Explanation: Improves health. - Smoking effect?
Answer: Lung damage
Explanation: Reduces oxygen intake. - Alcohol effect?
Answer: Liver damage
Explanation: Affects metabolism. - Pathogens?
Answer: Disease-causing organisms
Explanation: Include bacteria and viruses. - Immunity?
Answer: Body defense
Explanation: Protects against infection. - Antibodies?
Answer: Fight pathogens
Explanation: Produced by immune system. - Epidemic?
Answer: Disease spread
Explanation: Affects many people. - Clean water?
Answer: Essential
Explanation: Prevents diseases. - Air quality?
Answer: Affects breathing
Explanation: Pollution harms lungs. - Environment?
Answer: Surroundings
Explanation: Affects organism survival. - Biology importance?
Answer: Improves life
Explanation: Applied in all life aspects.
91–100 follow same logic:
91. Health education prevents disease – awareness
92. First aid saves lives – emergency care
93. Agriculture feeds population – food supply
94. Fertilizers improve soil – nutrients
95. Crop rotation prevents depletion – soil health
96. Irrigation supplies water – farming
97. Pest control protects crops – yield
98. Forestry manages trees – sustainability
99. Fisheries provide food – protein source
100. Biology supports development – global impact
Final Conclusion
Understanding Biology goes beyond memorizing answers—it requires grasping the concepts behind each question. WAEC and NECO exams often repeat patterns, so practicing with explanations gives you a strong advantage.
Final Exam Tips:
- Focus on understanding processes
- Practice past questions regularly
- Study diagrams and labeling
- Revise weak topics daily
