WASSCE 2019 Biology Questions and Answers
Biology Practice Questions with Detailed Answers, Explanations, MCQs, Topic Analysis and Difficulty Assessment
WASSCE Biology Questions — Practice Set
Biology questions in senior secondary examinations commonly test a mixture of biological knowledge, interpretation, application and practical reasoning. A strong revision plan should therefore cover cells, nutrition, transport, respiration, reproduction, genetics, ecology, evolution, plant biology and human health.
The questions below are written as an original examination-style practice set using the keyword theme WASSCE 2019 Biology Questions. Each question has a separate answer, explanation and difficulty analysis.
These are original Biology revision questions inspired by common secondary school examination topics. They are not a word-for-word reproduction of an official 2019 examination paper.
Section A — Biology Questions with Answers
Answer
- A plant cell normally has a cellulose cell wall, while an animal cell does not.
- Plant cells contain chloroplasts in photosynthetic tissues, while animal cells do not.
- Plant cells commonly possess a large permanent vacuole, whereas animal cells generally have smaller temporary vacuoles or lack a large central vacuole.
Explanation
Plant cells are adapted for photosynthesis, structural support and storage. The cellulose cell wall provides mechanical strength, chloroplasts contain chlorophyll for photosynthesis, and the large vacuole helps maintain cellular turgidity.
Animal cells do not require a cellulose wall or chloroplasts because they obtain organic nutrients rather than producing their own food by photosynthesis.
Question Analysis
Answer
Water enters the plant cell through the partially permeable cell membrane by osmosis. The vacuole expands and the cell becomes turgid.
Explanation
A dilute external solution has a higher water potential than the cell contents. Water therefore moves into the cell through the partially permeable membrane.
The cell wall prevents the cell from bursting under normal conditions and the increasing internal pressure produces a turgid cell.
Question Analysis
Answer
Two factors include:
- Light intensity
- Carbon dioxide concentration
- Temperature
- Water availability
For example, increasing light intensity can increase the rate of photosynthesis when light is the limiting factor, until another factor becomes limiting.
Explanation
Photosynthesis depends on several environmental conditions. If one factor is present at a level that limits the process, increasing another factor may have little effect until the limiting factor is improved.
At very high temperatures, enzyme-controlled reactions associated with photosynthesis can be impaired, so the relationship with temperature is not simply an unlimited increase.
Question Analysis
Answer
Bile emulsifies fats into smaller droplets, increasing the surface area available for lipase action. It also helps provide a suitable alkaline environment in the small intestine.
Explanation
Bile does not chemically digest fat itself. Its emulsifying action breaks large fat globules into smaller droplets. This increases the surface area on which lipase can act.
Question Analysis
Answer
Very high temperatures can disrupt bonds maintaining the enzyme’s three- dimensional structure. The active site changes shape, reducing the ability of the substrate to bind effectively. The enzyme becomes denatured.
Explanation
Enzymes are proteins with specific three-dimensional structures. Increasing temperature initially increases molecular movement and can increase reaction rate up to an optimum. Beyond the suitable range, structural changes can alter the active site.
Question Analysis
Answer
Most aerobic respiration occurs in the mitochondria of eukaryotic cells. The process releases usable energy from organic molecules in the form of ATP, which supports cellular activities.
Explanation
Glucose and other respiratory substrates are broken down through a series of reactions. The mitochondria contain structures and enzymes involved in the later stages of aerobic respiration and ATP production.
Question Analysis
Answer
Lungs → pulmonary veins → left atrium → left ventricle → aorta → body arteries → tissue capillaries → veins → venae cavae → right atrium → right ventricle → pulmonary artery → lungs.
Explanation
Oxygenated blood returns from the lungs through the pulmonary veins. It enters the left side of the heart and is pumped through the aorta to the body.
After oxygen is delivered to tissues, deoxygenated blood returns to the right side of the heart and is pumped through the pulmonary artery back to the lungs.
Question Analysis
Answer
Homeostasis is the maintenance of relatively stable internal conditions despite changes in the external environment.
Examples include regulation of body temperature, blood glucose concentration and blood water balance.
Explanation
Cells work best within particular internal conditions. Feedback mechanisms help detect changes and produce responses that move the internal environment towards an appropriate range.
Question Analysis
Answer
Fertilisation is the fusion of a sperm cell and an egg cell to form a zygote.
Implantation is the attachment and embedding of the early embryonic structure into the lining of the uterus.
Explanation
These are different stages. Fertilisation begins the formation of the new diploid organism, while implantation allows the developing embryo to become established in the uterine lining.
Question Analysis
Answer
Possible genotypes:
- AA
- Aa
- aa
Expected genotypic ratio:
1 AA : 2 Aa : 1 aa
Working
Each parent can produce two types of gametes: A and a.
Combining the gametes produces:
| A | a | |
|---|---|---|
| A | AA | Aa |
| a | Aa | aa |
Question Analysis
Answer
Mutualism: both organisms benefit from the relationship.
Example: nitrogen-fixing bacteria living in association with leguminous plants.
Parasitism: one organism benefits while the host is harmed.
Example: a tapeworm living inside an animal host.
Explanation
Ecological interactions can affect participating organisms differently. Mutualism produces benefits for both partners, while parasitism provides a benefit to the parasite at the expense of its host.
Question Analysis
Answer
Energy is lost at each trophic level through processes such as respiration, movement, heat loss, excretion and material that is not eaten or digested. Therefore, only a fraction of the energy is transferred to the next level.
Explanation
Producers capture energy and incorporate it into organic matter. Herbivores obtain some of this energy, but much is used for life processes. Carnivores then obtain only part of the energy stored in the organisms they consume.
Question Analysis
Answer
Transpiration is the loss of water vapour from the aerial parts of a plant, mainly through stomata.
Factors include:
- Temperature
- Humidity
- Wind speed
- Light intensity
Explanation
Environmental conditions alter the water vapour concentration gradient between the leaf and surrounding air and can affect stomatal behaviour. Warm, dry and moving air can generally increase water loss when stomata are open.
Question Analysis
Answer
- The broad surface provides a large area for capturing light.
- The thin structure provides a short distance for diffusion of gases.
- The palisade mesophyll contains many chloroplasts.
- Stomata allow gaseous exchange.
- Veins supply water and transport manufactured sugars away.
Explanation
Leaf structure reflects its photosynthetic function. Several features work together to provide light capture, carbon dioxide supply, water delivery and movement of photosynthetic products.
Question Analysis
Answer
- Individuals in a population show variation.
- Some variation is inherited.
- Individuals with a beneficial characteristic may survive or reproduce more successfully in a particular environment.
- They pass the associated alleles to their offspring.
- Over generations, the beneficial allele can become more common in the population.
Explanation
Natural selection acts on differences in survival and reproductive success. It does not create a required characteristic because an organism needs it. Instead, existing heritable variation can lead to different reproductive outcomes.
Question Analysis
Section B — 40 Biology MCQs
Choose the best answer for each question. The correct answer is displayed after every question for revision.
Which structure controls many activities of a eukaryotic cell?
Which structure is characteristic of plant cells?
Diffusion is the net movement of particles:
Osmosis involves the movement of:
The region of an enzyme where a substrate binds is the:
Which pigment is primarily associated with capturing light energy for photosynthesis?
Which gas is used by plants as a carbon source during photosynthesis?
Which organelle is strongly associated with aerobic respiration?
Which enzyme begins protein digestion in the stomach?
Most absorption of digested nutrients takes place in the:
Which blood cells transport most oxygen?
Which vessel carries oxygenated blood from the lungs to the heart?
Which chamber pumps blood into the aorta?
Homeostasis refers to:
Which organ is primarily responsible for producing urine?
The basic functional cell of the nervous system is the:
A reflex action is usually:
Which hormone helps reduce blood glucose concentration?
The male gamete in humans is the:
Fertilisation produces a:
A segment of DNA that influences a particular inherited characteristic is a:
Chromosomes are mainly composed of DNA associated with:
Meiosis is important because it produces:
Which can contribute to genetic variation?
The place where an organism normally lives is its:
The first trophic level in most ecosystems consists of:
Which organisms are important decomposers?
A population is made up of:
In mutualism:
In parasitism:
Most transpiration from leaves occurs through:
The xylem mainly transports:
The phloem transports:
Which leaf feature provides a large surface for light absorption?
Natural selection acts directly on:
An adaptation is a feature that:
Which organism is a fungus?
Which type of organism causes many infectious diseases?
Which cells are important in specific immune responses?
Which level of organisation is higher than a tissue?
WASSCE Biology Topic Analysis
| Biology Topic | Major Areas | Question Style | Difficulty |
|---|---|---|---|
| Cell Biology | Cell structures and functions | Comparison / Theory | Easy |
| Transport | Diffusion and osmosis | Explanation | Moderate |
| Plant Nutrition | Photosynthesis and limiting factors | Application | Moderate |
| Human Nutrition | Digestion and absorption | Function | Easy–Moderate |
| Enzymes | Temperature and activity | Explanation | Moderate |
| Respiration | Energy release | Theory | Easy |
| Transport in Humans | Blood and circulation | Process | Moderate |
| Homeostasis | Internal regulation | Definition | Easy |
| Reproduction | Fertilisation and implantation | Comparison | Easy |
| Genetics | Inheritance and Punnett squares | Application | Moderate |
| Ecology | Food chains and interactions | Explanation | Moderate |
| Evolution | Natural selection | Reasoning | Challenging |
Biology Paper Difficulty Analysis
Easy-Level Areas
Questions based on definitions, basic cell structures, simple biological functions and straightforward identification are generally easier when the fundamentals have been learned properly.
Moderate-Level Areas
Transport, enzyme activity, circulation, ecology and genetics often require students to explain relationships rather than simply recall a term.
Challenging Areas
Natural selection, experimental interpretation, complex inheritance and multi-step physiological processes can require several linked ideas. Students should practise explaining the sequence rather than memorising isolated statements.
Biology Revision Guide
1. Master Cell Biology
Know the functions of major cell structures and understand how specialised cells are adapted to their roles. Compare plant and animal cells carefully.
2. Understand Transport Processes
Learn the difference between diffusion, osmosis and active transport. Always pay attention to concentration or water-potential differences and whether energy is required.
3. Study Human Systems as Processes
For digestion, circulation, respiration, excretion and reproduction, learn the sequence of events rather than memorising disconnected organ names.
4. Practise Genetics
Learn genotype, phenotype, allele, homozygous, heterozygous, dominant and recessive terminology. Practise Punnett squares and probability questions.
5. Learn Ecology with Examples
Understand habitats, populations, communities, food chains, food webs, energy flow, nutrient cycles and relationships between organisms.
6. Understand Evolution
Natural selection questions often require a sequence: variation, inheritance, selection pressure, differential survival or reproduction and change in population characteristics over generations.
Common Mistakes in Biology Examinations
Using Vague Definitions
Avoid definitions that merely repeat the word being defined. Use the key biological feature that distinguishes the process or structure.
Confusing Similar Terms
Fertilisation and implantation, diffusion and osmosis, habitat and niche, and genotype and phenotype should be clearly distinguished.
Giving Examples Without Explanation
When a question asks you to explain, an example alone may not be sufficient. State the biological reason as well.
Ignoring Question Commands
Words such as state, describe, explain, compare and suggest require different levels of detail. Read the command word before writing the answer.
Forgetting Units and Labels
In practical and numerical Biology questions, always include appropriate units and clearly label graphs, tables and diagrams.
Frequently Asked Questions
What are WASSCE Biology questions?
WASSCE Biology questions assess knowledge and understanding of biological concepts such as cells, nutrition, transport, reproduction, genetics, ecology, evolution and human biology.
Are these the exact 2019 WASSCE Biology questions?
No. This page contains original WASSCE-style practice questions based on common Biology topics. It is not a word-for-word copy of an official 2019 examination paper.
How many MCQs are included in this practice set?
There are 40 Biology multiple-choice questions, each with four options and a marked correct answer.
Which Biology topics should I revise first?
Begin with cell biology, nutrition, transport, respiration and reproduction. Then move to genetics, ecology, plant physiology, evolution and human regulation.
How can I prepare for Biology theory questions?
Practise writing definitions, explanations, comparisons and biological sequences. Use precise scientific terms and include relevant examples when requested.
Why are diagrams important in Biology?
Diagrams can help students understand structures and processes and may also be required in practical or structured examination questions. Practise drawing simple, clearly labelled biological diagrams.
How should I approach a difficult Biology question?
Break the question into smaller parts. Identify the topic, underline the command word, recall the relevant biological process and construct the answer step by step.
Can MCQs improve Biology preparation?
Yes. MCQs are useful for checking terminology, identifying weak topics and improving speed. However, they should be combined with theory and structured question practice.
Final Biology Revision Summary
A strong Biology preparation strategy combines factual knowledge with the ability to explain biological processes. Students should understand how structures are adapted to their functions, how substances move through organisms, how energy is transferred and how organisms interact with their environment.
For human Biology, practise tracing processes such as circulation, digestion, reproduction and homeostasis. For plant Biology, focus on photosynthesis, transport and transpiration. For genetics and evolution, practise applying concepts to unfamiliar examples.
The MCQs in this article can be used as a quick revision test after completing the descriptive questions. Review every incorrect answer and return to the relevant topic before attempting another practice set.
Cell Biology → Transport → Nutrition → Enzymes → Respiration → Circulation → Homeostasis → Reproduction → Genetics → Plant Biology → Ecology → Evolution → MCQ Practice