WASSCE Biology Questions and Answers – Set 10
Fresh Biology examination-style practice material with solved questions, multiple-choice questions, explanations, topic analysis and difficulty assessment.
WASSCE Biology Practice Set 10
This Set 10 contains newly written Biology practice questions designed to help students revise important concepts commonly tested at senior secondary level.
The first part contains 50 structured questions. Every question includes an answer, explanation, topic, chapter and difficulty level. The second part contains 100 MCQs covering human Biology, plant Biology, genetics, ecology, microorganisms, reproduction and practical Biology.
These are original practice questions and are not presented as a verbatim reproduction of an official examination paper.
Section A — 50 Solved Biology Questions
Answer
The cell membrane controls the movement of substances into and out of the cell and helps maintain the cell’s internal environment.
Explanation
The membrane is selectively permeable, allowing some substances to cross more easily than others. This helps the cell maintain suitable internal conditions.
Answer
Osmosis is the net movement of water molecules through a selectively permeable membrane from a region of higher water potential to a region of lower water potential.
Explanation
Water moves down its water potential gradient until equilibrium is approached or another factor prevents further net movement.
Answer
Diffusion allows particles to move from areas of higher concentration to areas of lower concentration, helping cells exchange substances.
Explanation
Oxygen and carbon dioxide can cross cell surfaces by diffusion when a suitable concentration gradient exists.
Answer
Active transport moves substances against their concentration gradient, so cellular energy is required to drive the process.
Explanation
Transport proteins use energy, commonly from ATP, to move selected substances across membranes.
Answer
Enzymes act as biological catalysts and increase the rate of specific chemical reactions.
Explanation
Without enzymes, many cellular reactions would proceed too slowly to support normal life processes.
Answer
The active site of an enzyme has a shape and chemical environment that is compatible with particular substrate molecules.
Explanation
The interaction between substrate and active site allows the enzyme to catalyse a specific reaction efficiently.
Answer
The enzyme may become denatured and lose the shape of its active site.
Explanation
High temperature can disrupt bonds maintaining the enzyme’s three- dimensional structure, reducing or eliminating its activity.
Answer
Carbon dioxide and water are the main raw materials used in photosynthesis. Light energy is captured by chlorophyll.
Explanation
Plants use light energy to convert carbon dioxide and water into carbohydrates, releasing oxygen as a by-product in oxygenic photosynthesis.
Answer
Stomata regulate gas exchange and contribute to the movement of water vapour from leaves to the atmosphere.
Explanation
Carbon dioxide enters through stomata for photosynthesis, while oxygen and water vapour can move out.
Answer
Transpiration is the loss of water vapour from the aerial parts of a plant, mainly through stomata.
Explanation
Transpiration contributes to the movement of water through plants and helps generate a transpiration pull.
Answer
Xylem transports water and dissolved mineral ions from roots toward the shoot system.
Explanation
Xylem vessels are adapted to form continuous pathways through which water can move upward.
Answer
Phloem transports organic assimilates such as sucrose from sources to regions where they are needed or stored.
Explanation
This movement is known as translocation and can occur in different directions within the plant depending on source and sink relationships.
Answer
Plants require mineral ions for processes such as protein synthesis, enzyme function, chlorophyll production and healthy growth.
Explanation
Different mineral nutrients have different functions. Deficiency of a required mineral can produce characteristic symptoms.
Answer
Phototropism is the directional growth response of a plant organ to light.
Explanation
Shoots commonly show positive phototropism, growing toward a light source, which can improve light capture for photosynthesis.
Answer
Alveoli provide a large surface area for gas exchange between air and blood in the lungs.
Explanation
Their thin walls and rich blood supply help oxygen and carbon dioxide diffuse efficiently.
Answer
The diaphragm contracts and becomes flatter, increasing the volume of the thoracic cavity.
Explanation
The increased thoracic volume lowers pressure inside the lungs relative to the atmosphere, allowing air to enter.
Answer
Aerobic respiration produces carbon dioxide, water and usable cellular energy in the form of ATP.
Explanation
Oxygen is used as the final electron acceptor in aerobic respiration, which allows efficient energy release from glucose.
Answer
Anaerobic respiration involves incomplete breakdown of glucose, so less energy is extracted from each glucose molecule.
Explanation
In humans, anaerobic respiration produces lactate, while some microorganisms can produce ethanol and carbon dioxide.
Answer
The kidneys remove nitrogenous waste from the blood and help regulate water and mineral balance.
Explanation
Kidneys contribute to homeostasis by adjusting the composition of urine according to the body’s needs.
Answer
A nephron is the functional unit of the kidney involved in filtration, reabsorption and urine formation.
Explanation
Each nephron contains specialized regions that process filtrate and help produce urine with an appropriate concentration.
Answer
Homeostasis is the maintenance of relatively stable internal conditions despite changes in the external environment.
Explanation
Examples include regulation of body temperature, blood glucose and water balance.
Answer
Insulin helps lower blood glucose concentration by promoting glucose uptake and storage.
Explanation
Insulin is produced by beta cells in the pancreas and is important in glucose homeostasis.
Answer
Evaporation of sweat from the skin surface removes heat from the body.
Explanation
Evaporation requires energy, which is taken from the body’s thermal energy, thereby helping reduce skin temperature.
Answer
The spinal cord can coordinate rapid reflex responses by transmitting signals between sensory and motor pathways.
Explanation
This allows a response to begin rapidly without waiting for conscious processing by the brain.
Answer
A synapse is a junction between neurons or between a neuron and another cell where signals are transmitted.
Explanation
At many synapses, chemical neurotransmitters carry the signal across the small gap between cells.
Answer
Hormones act as chemical messengers that regulate processes such as growth, reproduction, metabolism and water balance.
Explanation
Hormones travel through body fluids and act on cells that possess suitable receptors.
Answer
Gametes are haploid so that fertilisation can combine two sets of chromosomes and restore the normal diploid number.
Explanation
Meiosis reduces the chromosome number during gamete formation.
Answer
Hormones regulate events such as follicle development, ovulation and changes in the uterine lining.
Explanation
The cycle involves coordinated changes in hormones produced by the pituitary gland and ovaries.
Answer
A haploid sperm nucleus fuses with a haploid egg nucleus, combining two sets of chromosomes.
Explanation
The resulting zygote therefore has chromosome sets contributed by both parents.
Answer
The placenta allows exchange of nutrients, oxygen and waste products between maternal and fetal blood systems without normally mixing the two blood supplies directly.
Explanation
The placenta also produces hormones that support pregnancy.
Answer
A homozygous genotype contains two identical alleles for a particular gene.
Explanation
An organism may be homozygous for one gene while being heterozygous for another.
Answer
A genetic cross is used to predict possible offspring genotypes and phenotypes from known parental genotypes.
Explanation
Punnett squares are commonly used to organize possible combinations of alleles.
Answer
Human eggs normally carry an X chromosome, while sperm can carry either an X or a Y chromosome.
Explanation
An X-bearing sperm can produce an XX zygote, while a Y-bearing sperm can produce an XY zygote.
Answer
Environmental conditions can affect how inherited characteristics are expressed, producing differences in phenotype.
Explanation
Nutrition, temperature, light and other environmental conditions can influence biological characteristics.
Answer
A characteristic must be capable of being passed to offspring for differences in reproductive success to alter its frequency in future generations.
Explanation
Non-heritable differences may affect an individual but are not directly passed to offspring through genetic inheritance.
Answer
A producer is an organism that makes organic food from inorganic substances, usually using light energy.
Explanation
Green plants and algae are common producers because they can carry out photosynthesis.
Answer
A consumer obtains organic nutrients by feeding on other organisms or their products.
Explanation
Animals are consumers because they cannot manufacture their own organic food from inorganic substances through photosynthesis.
Answer
Decomposers break down dead organic matter and return nutrients to the environment.
Explanation
Decomposition prevents organic material from accumulating and supports nutrient cycling.
Answer
Arrows show the direction of energy and food transfer from one trophic level to the next.
Explanation
For example, in a simple chain the arrow points from the organism being eaten toward the organism receiving the energy.
Answer
Much of the energy obtained by an organism is used for metabolism and lost as heat, leaving less energy available to the next trophic level.
Explanation
Energy transfer between trophic levels is therefore inefficient.
Answer
Birth rate and immigration can increase the size of a population.
Explanation
Population size is influenced by births, deaths, immigration and emigration.
Answer
Competition occurs when organisms require the same limited resources, such as food, water, space or mates.
Explanation
Competition can occur between members of the same species or between different species.
Answer
Predation is an interaction in which one organism captures and consumes another organism.
Explanation
Predation can influence population sizes and can contribute to natural selection.
Answer
Mutualism is an interaction between organisms of different species in which both partners benefit.
Explanation
Mutualistic relationships can provide benefits such as nutrients, protection or assistance in reproduction.
Answer
Nutrients carried into water bodies can stimulate excessive algal growth, which may eventually reduce dissolved oxygen when algae and other organic matter decompose.
Explanation
Severe oxygen depletion can create conditions that are harmful to fish and other aquatic organisms.
Answer
Biodiversity supports ecosystem stability, provides useful biological resources and maintains genetic and ecological variety.
Explanation
Loss of species can disrupt food webs and reduce ecosystem resilience.
Answer
Random sampling reduces selection bias and gives different areas a fairer chance of being included.
Explanation
A suitable sampling strategy makes the collected data more representative of the study area.
Answer
Changing one independent variable at a time makes it easier to determine whether that variable caused the observed change.
Explanation
Other relevant factors should be controlled so that the investigation can produce a meaningful conclusion.
Answer
An average summarizes repeated measurements and can reduce the influence of random variation in individual readings.
Explanation
Anomalous results should still be investigated rather than automatically removed.
Answer
A conclusion should be supported by the actual observations and measurements collected during the investigation.
Explanation
Using evidence prevents unsupported claims and allows other investigators to evaluate the reasoning behind the conclusion.
Section B — 100 Biology MCQs
Which structure controls movement of substances into and out of a cell?
Which organelle contains most of the genetic material in a typical eukaryotic cell?
Which organelle is strongly associated with aerobic respiration?
Movement of particles from high concentration to low concentration is:
Osmosis involves movement of:
Active transport usually requires:
Enzymes are biological:
The region of an enzyme where the substrate binds is the:
Excessive heat can cause an enzyme to:
Which gas is required for photosynthesis?
Chlorophyll primarily absorbs:
Gas exchange in leaves occurs mainly through:
Xylem mainly transports:
Phloem is mainly involved in:
Transpiration involves loss of:
Growth toward a light source is called:
Which substance is broken down during cellular respiration?
Aerobic respiration requires:
Anaerobic respiration occurs when:
Gas exchange in the lungs takes place mainly at the:
During inhalation, the diaphragm:
Which blood cells contain haemoglobin?
White blood cells are mainly involved in:
Platelets help with:
Which chamber pumps oxygenated blood into the systemic circulation?
Arteries generally carry blood:
Which vessels have valves that help prevent backflow?
Capillaries are adapted for:
The functional unit of the kidney is the:
Which organ removes urea from the blood?
Homeostasis refers to maintaining:
Which hormone lowers blood glucose?
Evaporation of sweat causes:
The basic conducting cell of the nervous system is the:
A reflex action is normally:
Neurotransmitters are released at many:
Gametes are produced through:
Fusion of male and female gametes is:
The product formed immediately after fertilisation is a:
Alternative forms of a gene are:
An organism with identical alleles is:
An organism with two different alleles is:
The observable characteristics of an organism are its:
The genetic constitution of an organism is its:
A change in DNA sequence is known as:
Natural selection favours characteristics that improve:
An adaptation must generally be:
The place where an organism lives is its:
The role of an organism within an ecosystem is its:
Green plants are usually:
Organisms that obtain energy by eating other organisms are:
Decomposers are important because they:
An organism that eats plants is a:
The first trophic level normally contains:
Energy is lost from organisms mainly through:
A group of organisms of the same species living in an area is a:
Different populations living together form a:
Which is an abiotic factor?
Which is a biotic factor?
Predation involves:
Mutualism benefits:
Excess nutrients in water can cause:
Which action supports biodiversity?
A disease-causing microorganism is called a:
Which practice can reduce transmission of many infectious diseases?
Antibodies recognize specific:
Vaccines are designed to stimulate:
Which enzyme digests starch?
Proteases digest:
Lipase breaks down:
Villi are found mainly in the:
The main purpose of villi is to increase:
Bile helps with digestion by emulsifying:
Which nutrient is mainly required for growth and tissue repair?
Vitamins are generally required in:
DNA is located in chromosomes mainly within the:
Mitosis normally produces:
Meiosis contributes to:
Genes are sections of:
Variation means:
Evolutionary change occurs across:
A characteristic that improves survival in a particular environment is an:
The variable deliberately changed is the:
The variable measured in an experiment is the:
Controlled variables should normally be:
Repeating an experiment helps assess:
Which instrument is suitable for measuring temperature?
Which instrument is used to measure mass?
Which graph is useful for comparing categories?
A scatter graph is useful for showing:
Quadrats are commonly used to investigate:
Random sampling helps reduce:
Which is quantitative data?
A hypothesis should be:
A conclusion should be based on:
Which structure is present in plant cells but absent from animal cells?
Which structure contains chlorophyll?
Which organ pumps blood around the body?
Which organ is mainly responsible for gas exchange?
What is the most effective way to use this practice set?
WASSCE Biology Set 10 — Paper Analysis
| Topic Area | Major Concepts | Question Approach | Difficulty |
|---|---|---|---|
| Cell Biology | Cell membrane, transport and organelles | Conceptual | Easy–Moderate |
| Enzymes | Specificity, active site and denaturation | Application | Moderate |
| Plant Biology | Photosynthesis, stomata, xylem, phloem and transpiration | Structure and function | Moderate |
| Respiration | Aerobic and anaerobic respiration | Comparison | Moderate–Hard |
| Excretion | Kidney, nephron and homeostasis | Application | Moderate |
| Nervous Coordination | Neurons, reflexes and synapses | Conceptual | Moderate |
| Hormonal Coordination | Hormones and internal regulation | Application | Moderate |
| Reproduction | Gametes, fertilisation and pregnancy | Understanding | Moderate |
| Genetics | Alleles, genotype, phenotype and inheritance | Reasoning | Moderate–Hard |
| Evolution | Variation, adaptation and natural selection | Analysis | Hard |
| Ecology | Food chains, populations, competition and conservation | Application | Moderate |
| Practical Biology | Variables, sampling, graphs and evidence | Evaluation | Moderate |
Difficulty Analysis
Easy questions: These mainly test definitions, basic biological functions and direct recall of important facts.
Moderate questions: These require students to connect structures with their functions or apply familiar concepts to biological situations.
Difficult questions: These involve multi-step reasoning, such as explaining energy loss, natural selection, anaerobic respiration, hormonal regulation and experimental reliability.
Chapter-Wise Revision Guide
| Chapter | Revision Focus |
|---|---|
| Cell Biology | Cell structures, membranes, diffusion, osmosis and active transport. |
| Enzymes | Active site, substrate, temperature, pH and denaturation. |
| Photosynthesis | Raw materials, chlorophyll, light and gas exchange. |
| Plant Transport | Xylem, phloem, transpiration and mineral uptake. |
| Respiration | Aerobic respiration, anaerobic respiration and gas exchange. |
| Excretion | Kidneys, nephrons, urine formation and homeostasis. |
| Coordination | Neurons, synapses, reflexes and hormones. |
| Reproduction | Gametes, fertilisation, menstrual cycle and placenta. |
| Genetics | DNA, genes, chromosomes, alleles and inheritance. |
| Evolution | Variation, adaptation and natural selection. |
| Ecology | Populations, communities, food chains, competition and conservation. |
| Practical Biology | Variables, controls, sampling, graphs, averages and conclusions. |
Frequently Asked Questions
How many solved questions are in Set 10?
Set 10 contains 50 structured Biology questions with answers and explanations.
How many MCQs are included?
There are 100 Biology MCQs with four options and marked correct answers.
Are these official WASSCE 2019 questions?
No. This is original WASSCE-style practice content created for Biology revision and examination preparation.
Which Biology topics are covered?
The set includes cell Biology, transport, enzymes, photosynthesis, respiration, excretion, homeostasis, coordination, reproduction, genetics, evolution, ecology, environmental Biology and practical Biology.
Which topics require the most reasoning?
Genetics, evolution, respiration, homeostasis, energy transfer and experimental analysis generally require more than simple memorization.
How should the MCQs be attempted?
Attempt all questions without checking the answers first. After finishing, review every incorrect response and revise the corresponding topic.
How can Biology marks be improved?
Focus on understanding biological processes, learning correct scientific terms, practising diagrams and analysing mistakes from previous practice sets.
Final Revision Checklist
- Revise major cell organelles and their functions.
- Understand diffusion, osmosis and active transport.
- Learn enzyme action and factors affecting enzyme activity.
- Revise photosynthesis and leaf adaptations.
- Understand xylem and phloem transport.
- Study transpiration and stomatal regulation.
- Revise aerobic and anaerobic respiration.
- Learn the structure and function of alveoli.
- Understand kidney function and nephron structure.
- Revise homeostasis and blood glucose regulation.
- Study reflex actions and synapses.
- Understand hormonal coordination.
- Revise gamete formation and fertilisation.
- Study placenta and reproductive hormones.
- Practise genetic terminology.
- Understand mutation, variation and natural selection.
- Revise producers, consumers and decomposers.
- Study food chains and energy transfer.
- Understand population interactions.
- Revise pollution and biodiversity conservation.
- Practise identifying independent and dependent variables.
- Review graphs, sampling and experimental conclusions.