WASSCE Biology Past Questions and Answers 2024

The West African Senior School Certificate Examination (WASSCE) Biology 2024 past questions and answers serve as a valuable resource for students preparing for the exam. By reviewing past questions, students gain insight into the exam format, commonly tested areas, and the types of questions they are likely to encounter. Detailed answers and explanations help in understanding key concepts, improving recall, and enhancing exam performance.

THEORY 

SECTION A

Answer Two Questions only from this Section

1. (a) Explain briefly the reason why a cell is considered a functional unit of life.

• A cell is considered the functional unit of life because it is the smallest structure capable of carrying out all the life processes, including metabolism, growth, and reproduction. All living organisms are made up of cells, and they perform the basic functions necessary for survival. Cells contain organelles that each have specific functions, contributing to the overall functioning of the organism.

(b) Outline the process of endocytosis in a cell.

• Endocytosis is a cellular process where a cell engulfs material from the external environment into the cell. It involves the plasma membrane folding inward to form a pocket around the material, which eventually pinches off to form a vesicle containing the ingested material. There are two main types of endocytosis: phagocytosis (ingestion of large particles) and pinocytosis (ingestion of fluids and solutes).

(c) State two functions of endocytosis in organisms.

1. Endocytosis allows cells to take in nutrients, which are essential for survival and cellular function.
2. It helps remove harmful substances or pathogens from the cell's external environment by engulfing them.

(d) Explain briefly the role of pheromones in insects.

• Pheromones are chemical signals released by insects that affect the behavior of other members of the same species. They are commonly used in communication for various purposes, such as attracting mates, marking territory, or signaling danger. For example, female insects may release pheromones to attract males for mating, while social insects like ants use pheromones to guide others to food sources.

(e) State two applications of pheromones in biological pest control:

• Used in insect traps to monitor pest populations.
• Disrupt mating patterns of pests to reduce reproduction rates.

(f) (i) Name the two components of the stoma of a plant:

• Guard cells
• Stomatal pore

(ii) Explain briefly the mechanism of opening of the stomata in plants:

• When guard cells absorb water, they become turgid, causing the stomatal pore to open. This occurs due to the active transport of potassium ions (K+) into the guard cells, lowering the water potential and resulting in water entering by osmosis.

2. (a) (i) Explain the term nutrition:

• Nutrition is the process by which organisms obtain and utilize food substances to maintain life, support growth, repair tissues, and provide energy.

(ii) Name the mode of nutrition in the following organisms:

• Fern: Autotrophic
• Plasmodium: Parasitic
• Tapeworm: Parasitic
• Toad: Heterotrophic
• Rhizopus: Saprophytic
• Chlamydomonas: Autotrophic
• Hibiscus: Autotrophic

(b) State four ways each by which the feeding habit of Euglena viridis is:

(i) Similar to that of humans:

• Both can absorb nutrients through food ingestion.
• Both use food for energy production.
• Both undergo metabolism to break down food.
• Both rely on external food sources.

(ii) Different from that of humans:

• Euglena can photosynthesize due to chloroplasts, while humans cannot.
• Euglena absorbs food through its body surface, while humans ingest it via the mouth.
• Euglena can switch between autotrophic and heterotrophic nutrition, whereas humans are strictly heterotrophic.
• Euglena lacks a digestive system, while humans have a complex digestive tract.

(c) Explain briefly how food swallowed by a patient lying flat on a hospital bed reaches the stomach of the patient:

• Food moves from the mouth to the stomach through the process of peristalsis. This is a wave-like muscle contraction in the esophagus that pushes food downwards, regardless of the body's position.

3. (a) (i) What is humidity?

• Humidity is the amount of water vapor present in the air, often expressed as a percentage of the maximum amount of moisture the air can hold at a given temperature.

(ii) List three abiotic factors that are affected by humidity:

• Temperature
• Soil moisture
• Rate of evaporation

(b) State two effects each of the following factors on Spirogyra in its habitat:

(i) Temperature:

• Higher temperatures can increase metabolic activities and growth.
• Extremely high temperatures may cause desiccation or cell damage.

(ii) Rainfall:

• Increases water availability, aiding growth.
• Can also cause dilution of nutrients in its habitat.

(iii) Light intensity:

• Higher light intensity promotes photosynthesis.
• Low light can limit energy production and growth.

(iv) pH:

• Optimal pH supports enzyme activity and cellular processes.
• Extremes in pH can disrupt cell functions and inhibit growth.

(c) Explain briefly the process of natural selection in a population.

• Natural selection is the process where individuals with favorable traits are more likely to survive and reproduce. Over time, these advantageous traits become more common in the population, while individuals with less favorable traits may not survive as easily.

(d) Name the causative organism of each of the following diseases:

(i) Cholera: Vibrio cholerae
(ii) Measles: Morbillivirus
(iii) Malaria: Plasmodium species (commonly Plasmodium falciparum, Plasmodium vivax)

4. (a) List two causes of diseases in humans.

1. Pathogenic microorganisms (such as bacteria, viruses, and fungi)
2. Genetic disorders (inherited diseases such as sickle cell anemia)

(b) (i) Complete the table below by naming two blood components that protect the body against diseases and explain one function of each.

Blood components	One function
White blood cells (leukocytes)	Fight infections by engulfing pathogens or producing antibodies
Platelets	Help in blood clotting, which prevents entry of pathogens through wounds

(ii) Distinguish between antibodies and antigens.

• Antibodies are proteins produced by the immune system in response to the presence of antigens. They recognize and neutralize foreign invaders like bacteria and viruses.

• Antigens are foreign substances or molecules (often proteins or polysaccharides) that induce an immune response, especially the production of antibodies.

(c) A man with homozygous Rhesus positive blood (RR) married a woman with homozygous Rhesus negative blood (rr) and had four offspring.

(i) With the aid of a genetic diagram, determine the Rhesus factors of their offspring.

	r	r
R	Rr	Rr
R	Rr	Rr

• All offspring will have the genotype Rr.

(ii) What is the phenotype of the offspring?

• All the offspring will be Rhesus positive (since the Rhesus positive trait is dominant).

(iii) What is the genotypic ratio of the offspring?

• The genotypic ratio is 100% Rr.

SECTION B

Answer All Questions in this Section

5. (a) List four processes by which substances are transported into the cells of mammals.

1. Diffusion
2. Osmosis
3. Active transport
4. Facilitated diffusion

(b) List four mineral salts that could be found in a soil sample.

Four mineral salts that could be found in a soil sample are:

1. Calcium carbonate (CaCO₃)
2. Potassium nitrate (KNO₃)
3. Magnesium sulfate (MgSO₄)
4. Sodium chloride (NaCl)

(c) Name three types of muscles found in mammals.

1. Skeletal muscle
2. Smooth muscle
3. Cardiac muscle

(d) Name two types of root modifications in plants found in swampy areas of Ghana.

1. Pneumatophores
2. Prop roots

(e) State one adaptation each of the root modifications named in 5(d).

1. Pneumatophores: These are specialized aerial roots that grow upwards to help with gas exchange in waterlogged soils.
2. Prop roots: These roots provide additional support to plants growing in unstable, waterlogged environments.

(f) Explain briefly the involvement of the Forestry Commission in Integrated Water Resources Management.
The Forestry Commission plays a critical role in managing and protecting watersheds through sustainable forest management practices. They help prevent deforestation and degradation, ensuring the protection of water sources. Their role includes regulating land use in forests to maintain water quality, managing afforestation programs, and collaborating with other organizations for integrated water management systems.

(g) (i) State four ways in which additives are important in food industries.

1. Preservation: Additives such as preservatives prevent spoilage and extend shelf life.
2. Flavor enhancement: Additives improve the taste of food products, such as using flavor enhancers like monosodium glutamate (MSG).
3. Color improvement: Food colorings are used to make food visually appealing.
4. Texture improvement: Additives like emulsifiers and stabilizers maintain the texture and consistency of food.

(ii) State two harmful effects of food additives to humans.

1. Allergic reactions or hypersensitivity in some individuals, especially to substances like sulfites or artificial colorings.
2. Long-term health risks such as potential carcinogenic effects from certain preservatives like nitrites.

(h) Outline four steps in the procedure of identifying iron in a soil sample.

1. Soil sample collection: Gather a representative soil sample from the field.
2. Soil digestion: Treat the soil sample with acid (usually hydrochloric acid) to dissolve the minerals, including iron.
3. Filtration: Filter the solution to remove solid particles, leaving behind the dissolved iron in the solution.
4. Testing with reagents: Use a reagent like potassium thiocyanate to react with the iron in the solution, producing a red color if iron is present.

OBJECTIVES

Answer All Questions in this Section

1.  Animals that can vary their body temperature in response to changes in their environments are
A. poikilothermic.
B. homoiothermic.
C. diploblastic.
D. triploblastic.
Answer: A. poikilothermic.

2.  The type of view of the drawing is
A. posterior.
B. ventral.
C. anterior.
D. lateral.
Correct Answer: D. lateral.

3. Prokaryotes belong to the Kingdom
A. Animalia.
B. Protista.
C. Fungi.
D. Monera.
Answer: D. Monera.

The diagram below is an illustration of a member of a Class in the Division Bryophyta. Study it and answer questions 4 to 6.

4.  The organism illustrated belongs to the Class
A. Musci.
B. Pteridopsida.
C. Hepaticae.
D. Dicotyledoneae.
Answer: C. Hepatiae

5.  The part labelled I is the
A. sporophyte.
B. apical notch.
C. rhizoid.
D. gemma cup.
Answer: D. Gemma cup.

6. The main function of the part labelled II is
A. for asexual reproduction.
B. production of multicellular reproductive bodies.
C. for absorption of light during photosynthesis.
D. to reduce transpiration from its body tissues.
Answer: C. for absorption of light during photosynthesis.

7.  During photosynthesis in green plants, the formation of ATP occurs in the
A. epidermis.
B. xylem.
C. bark.
D. chloroplast.
Answer: D. chloroplast.

The information below is on the stages of conjugation in Spirogyra. Use it to answer questions 8 to 10.

I - Conjugation tube is formed.
II - Protuberances from each cell go to meet each other.
III - Two filaments lie side by side.
IV - The male gamete passes through the conjugation tube into the opposite cell to form a zygote.

8.  The correct sequence of conjugation in Spirogyra is
A. I → II → III → IV.
B. II → III → IV → I.
C. III → II → I → IV.
D. IV → I → II → III.
Answer: C. III → II → I → IV.

9.  The biological importance of II is that it
A. is where the zygote is formed.
B. is where the male gamete is formed.
C. protects the gamete.
D. forms the conjugation tube.
Answer: D. forms the conjugation tube.

10. Conjugation also takes place in
A. Amoeba.
B. Paramecium.
C. virus.
D. yeast.
Answer: B. Paramecium.

11. Which of the following vertebrae has vertebrarterial canal?
A. Atlas.
B. Thoracic.
C. Lumbar.
D. Sacrum.
Answer: A. Atlas.

The diagram below is an illustration of the transport system in an animal. Study it and answer questions 12 and 13.

12. The type of transport system illustrated is
A. closed circulatory system.
B. lymphatic system.
C. open circulatory system.
D. respiratory system.
Answer: C. open circulatory system.

13.  The class of animals that exhibits the illustrated transport system is
A. Amphibia.
B. Aves.
C. Insecta.
D. Reptilia.
Answer: C. Insecta.

14. The function of leucocytes is to
A. facilitate blood clotting.
B. engulf bacteria.
C. destroy lymph in the system.
D. transport oxygen to the cells.
Answer: B. engulf bacteria.

 

A solution of starch and glucose was put in a dialysis bag and suspended in a beaker of water in diagram I. Diagram II is a graph of the results from the experiment. Study them and answer questions 26 and 27. (Diagram I and II are mentioned, showing the dialysis bag and the graph of results.)

25. The process by which fats are broken down into droplets for easy digestion is known as
A. deamination.
B. assimilation.
C. emulsification.
D. absorption.
Answer: C. emulsification.

26.  Which of the following summaries best describes the amount of water, starch, and glucose in the dialysis bag over the course of the experiment?
A. Water - Increases, Starch - Decreases, Glucose - Unchanged.
B. Water - Decreases, Starch - Unchanged, Glucose - Increases.
C. Water - Unchanged, Starch - Increases, Glucose - Decreases.
D. Water - Increases, Starch - Unchanged, Glucose - Decreases.
Answer: D. Water - Increases, Starch - Unchanged, Glucose - Decreases.

27. The aim of the experiment is to investigate how
A. transpiration occurs in plants.
B. molecular sizes affect movement through permeable membranes.
C. semi-permeable membranes are functional.
D. water dissolves solutes.
Answer: B. molecular sizes affect movement through permeable membranes.

28. Rhizopus is a saprophyte because it: A. digests food extracellularly.
B. feeds on living organisms.
C. grows on trees.
D. manufactures its food.

Answer: A. digests food extracellularly.

29. Which of the following statements is likely to be an effect of the elimination of decomposers from an ecosystem? A. Concentration of carbon (IV) oxide will increase.
B. Food webs would be more complicated.
C. Refuse will accumulate over time.
D. Soil nutrients will increase.

Answer: C. Refuse will accumulate over time.

30. In which of the following aquatic habitats would there be the least salinity? A. Freshwater
B. Estuaries
C. Swamps
D. Marine

Answer: A. Freshwater

31. Which of the food chains are not correct?
I: maize → man → grass → lion
II: grass → grasshopper → lizard → hawk
III: grass → zebra → monkey → lion
IV: detritus → lion → detritus → grass

A. II and III only
B. III and IV only
C. I, III and IV only
D. II, III and IV only

Answer: C. I, III, and IV only

32. Which of the following statements about the food chain labelled IV is correct?
A. Grass is the saprophyte.
B. Detritus is the producer.
C. Lion is correctly placed.
D. Arrows are wrongly placed.

Answer: D. Arrows are wrongly placed.

33. In an ecosystem, bacteria and fungi are regarded as:
A. producers.
B. scavengers.
C. predators.
D. decomposers.

Answer: D. decomposers.

34. Breathing roots are:
A. an adaptation for desert life.
B. an adaptation for swamps.
C. found in all aquatic plants.
D. found in epiphytes.

Answer: B. an adaptation for swamps.

The diagram below is an illustration of an instrument used for ecological studies. Study it and answer questions 35 and 36.

35. The instrument is used to catch:
A. earthworms and ants.
B. caterpillars and frogs.
C. grasshoppers and butterflies.
D. earthworms and butterflies.

Answer: C. grasshoppers and butterflies.

36. If the length of the collecting net is h cm, what would be the implication to its function?
A. The organisms caught would escape easily.
B. Swinging the instrument would be difficult.
C. The instrument would trap the intended organism.
D. It will make the handle inefficient.

Answer: A. The organisms caught would escape easily.

37. A farmer planted beans, maize, and potatoes on the same piece of land. What type of interaction would likely occur on the farmland?
A. Interspecific competition
B. Intraspecific competition
C. The farmland will be easily weathered.
D. The nutrients on the farmland will easily be depleted.

Answer: A. Interspecific competition

38. The term used to describe the cutting down of trees on the land is:
A. afforestation.
B. deforestation.
C. reafforestation.
D. forestry.

Answer: B. deforestation.

39. What is the likely effect of the action on the environment?
A. It will lead to a reduced effect of global warming.
B. There will be growth of new species of organisms.
C. There will be increased accumulation of oxygen gas.
D. The area might be prone to flooding.

Answer: D. The area might be prone to flooding.

40. Which of the following natural resources is formed from the remains of dead animals?
A. Coal
B. Firewood
C. Iron ore
D. Fossil fuel

Answer: D. Fossil fuel

41. Which of the following statements about human blood groups is not correct?
A. O is recessive.
B. A is dominant over B.
C. B is dominant over O.
D. A and B are codominant.

Answer: B. A is dominant over B.

42. The types of fingerprint patterns in human are:
A. whorl, alternate, opposite, and compound.
B. compound, loop, whorl, and alternate.
C. whorl, arch, compound, and loop.
D. arch, simple, compound, and opposite.

Answer: C. whorl, arch, compound and loop

43. An example of physiological variation is:
A. blood group.
B. height of plant.
C. skin colour.
D. body size.

Answer: A. blood group.

44. The sex of humans is determined by the inheritance of:
A. a pair of homologous chromosomes.
B. X and Y chromosomes.
C. an extra chromosome in males.
D. a dominant gene.

Answer: B. X and Y chromosomes.

45. Genes are found in the:
A. centriole.
B. centrosome.
C. chiasma.
D. chromosome.

Answer: D. chromosome.

46. Which of the following statements is not correct? The:
A. two children belong to the man if both parents are heterozygous.
B. man can never have a child that has blood group O.
C. second child only belongs to the man if both parents are homozygous.
D. first child does not belong to the man if the man is homozygous.

Answer: D. first child does not belong to the man if the man is homozygous.

47. If both parents are homozygous, the children would likely belong to blood group:
A. AB.
B. O.
C. A.
D. B.

Answer: B. O.

48. The evidence of evolution that paleontology is based on is:
A. fossils.
B. vestigial organs.
C. homologous organs.
D. comparative biochemistry.

Answer: A. fossils.

49. Which of the following evolutionary trends in plants is correct?
A. Ferns → algae → mosses → seed plants.
B. Ferns → mosses → algae → seed plants.
C. Algae → mosses → ferns → seed plants.
D. Mosses → algae → ferns → seed plants.

Answer: C. Algae → mosses → ferns → seed plants.

50. Which of the following processes provides the material for evolution?
A. Germline mutation.
B. Territoriality.
C. Nuptial flight.
D. Use and disuse of organs.

Answer: A. Germline mutation.

END OF PAPER