Waec Biology 2024 Expo Answer


Welcome to “Naijaclass Academy” For Waec Biology 2024 Expo Answer


Date: Thursday, 23rd May, 2024
Biology (Essay & Objective)  9:30 am – 12:00pm





(i) It filters blood to form glomerular filtrate.
(ii) It removes waste products and excess substances from the bloodstream.
(iii) It initiates the urine formation process by allowing water and small molecules to pass through while retaining larger molecules like proteins.

Bowman’s capsule:
(i) It collects the filtrate produced by the glomerulus.
(ii) It forms primary urine by capturing the filtrate and directing it into the nephron.
(iii) It serves as a funnel, guiding the filtrate into the proximal convoluted tubule for further processing.

Proximal convoluted tubule:
(i) It reabsorbs water, ions, and nutrients from the filtrate back into the bloodstream.
(ii) It plays a crucial role in secreting waste products such as hydrogen ions and ammonia into the tubular fluid.
(iii) It maintains pH balance by selectively reabsorbing bicarbonate ions and secreting hydrogen ions.

Distal convoluted tubule:
(i) It reabsorbs sodium and water, thus playing a key role in regulating blood pressure and fluid balance.
(ii) It secretes potassium and hydrogen ions, which helps in maintaining electrolyte and acid-base balance.
(iii) It also regulates calcium and phosphate levels in the blood, contributing to bone health and metabolic functions.

|ORGANISM | Structure.. |..Form in which|

|Paramecium|Contractile vacuole|Liquid (water)

|Flatworm |Flame cells| Ammonia|

|Earthworm|Nephridia | Urea|

|Cockroach|Malpighian tubules|Uric acid|

|Human | Kidneys| Liquid(urine)|

|Plant | Stomatal pore| Gaseous (water vapor, oxygen, carbon dioxide

(i) Oxygen
(ii) Carbon dioxide
(iii) Water vapor
(iv) Resins
(v) gums
(vi) Latex
(vii) Tannins
(viii) Essential oils



(i) Glomerulus:
The glomerulus filters blood to form a filtrate, which includes water, ions, and small molecules like glucose and amino acids, while retaining larger molecules such as proteins and cells.

(ii) Bowman’s Capsule:
The Bowman’s capsule collects the filtrate produced by the glomerulus and funnels it into the proximal convoluted tubule.

(iii) Proximal convoluted tubule:
The proximal convoluted tubule reabsorbs essential substances such as glucose, amino acids, and ions (e.g., sodium and chloride) from the filtrate back into the blood.

(iv) Distal convoluted tubule:
The distal convoluted tubule fine-tunes the reabsorption of ions and water, and it secretes additional waste products into the filtrate, helping to regulate electrolyte balance and pH.


(i) Flatworms
(ii) Earthworm
(iii) Cockroach
(iv) Human
(v) Plant

(i) Flame cells
(ii) Nephridia
(iii) Malpighian tubules
(iv) Kidneys
(v) Stomatal pore

(i) Ammonia
(ii) Urea
(iii) Uric acid
(iv) Liquid (urine)
(v) Oxygen, carbon dioxide, and water vapor

(i) Oxygen
(ii) Carbon dioxide
(iii) Water vapor
(iv) Resins
(v) Gums

(i) Mouth;
The mouth is responsible for the initial mechanical breakdown of food through chewing and the enzymatic breakdown of starches through the action of saliva.

(ii) Skin;
The skin regulates body temperature through the process of sweating, which also helps to excrete excess salts and maintain homeostasis.

(iii) Tongue;
The tongue assists in the manipulation of food for chewing and swallowing, and contains taste buds that help in the sensory evaluation of food.

(iv) Kidney;
The kidneys filter blood to remove waste products and excess substances, producing urine, which helps to maintain the body’s fluid and electrolyte balance.

(v) Stomach;
The stomach produces gastric juices, including hydrochloric acid and digestive enzymes, which help in the breakdown of food into a semi-liquid form called chyme.

(vi) Small Intestine;
The small intestine is the primary site for nutrient absorption; it continues the process of digestion with the help of enzymes and bile, and absorbs nutrients into the bloodstream.

(vii) Large Intestine;
The large intestine absorbs water and salts from the material that has not been digested as food, and compacts the remaining material into feces for excretion.

(viii) Liver;
The liver produces bile, which aids in the digestion and absorption of fats, and processes nutrients absorbed from the small intestine, detoxifying harmful substances and storing nutrients.

(i) Mouth (salivary glands produce amylase)
(ii) Stomach (produces pepsin)
(iii) Small intestine (produces various enzymes such as maltase, lactase, and sucrase; receives enzymes from the pancreas)

(i) Amylase (in saliva) – Breaks down starches into sugars.
(ii) Pepsin (in stomach) – Breaks down proteins into peptides.
(iii) Lipase (from pancreas) – Breaks down fats into fatty acids and glycerol.

(i) Glucose (from the breakdown of carbohydrates)
(ii) Amino acids (from the breakdown of proteins)

Excess salt can lead to increased blood pressure due to the retention of water, which increases the volume of blood.

(i) Energy – Carbohydrates in cassava provide a source of energy.
(ii) Protein – Groundnut soup contains proteins necessary for body repair and growth.
(iii) Nutrients – The meal provides essential vitamins and minerals required for overall health.


(i) Discoloration: The meat may turn brown or green.
(ii) Mold growth: Visible mold or fungal growth may appear on the surface.
(iii) Odor: A foul smell or strong odor may develop due to bacterial growth.
(iv) Texture: The meat may become slimy or sticky.

Decomposition (or putrefaction) caused by microbial activity.


(i) Refrigeration/Freezing
(ii) Salting
(iii) Smoking
(iv) Drying/dehydration

(i) Low temperature slows down microbial growth
(ii) Salt dehydrates microbes and inhibits their growth
(iii) Smoke contains compounds that kill or inhibit microbes
(iv) Removal of water inhibits microbial growth

(i) Temperature: High temperatures can accelerate the growth of bacteria and fungi, leading to faster decomposition of the meat.
(ii) Humidity: High humidity levels can create a conducive environment for microbial growth, increasing the rate of spoilage.

(i) Dried maize grains: Airtight storage (to prevent moisture absorption and pest infestation)
(ii) Fresh tomatoes: Canning (to prevent spoilage and extend shelf life)
(iii) Vegetables: Freezing (to retain nutrients and prevent spoilage)
(iv) Beans: Drying (to reduce moisture content and prevent microbial growth)
(v) Milk: Pasteurization (to kill harmful bacteria and extend shelf life)


Another version


(i) Chewing and breaking down the food
(ii) Producing saliva to moisten and lubricate the food
(iii) Initiating the digestive process through enzymatic action

(i) Regulating body temperature through sweating
(ii) Excreting waste products like urea and lactic acid
(iii) Absorbing certain substances through the skin

(i) Helping with chewing and mixing the food with saliva
(ii) Providing taste sensation and identifying the taste of the food
(iii) Assisting in the swallowing process

(i) Filtering the blood and removing waste products
(ii) Regulating the balance of water, salts, and minerals in the body
(iii) Producing urine for excretion

(i) Storing and breaking down the food through mechanical and chemical processes
(ii) Producing gastric acid and enzymes to aid in digestion
(iii) Mixing the food with digestive juices

-Small Intestine-
(i) Absorbing the majority of nutrients from the digested food
(ii) Producing enzymes to further break down the food
(iii) Transporting the digested nutrients to the bloodstream

-Large Intestine-
(i) Absorbing water from the remaining undigested food
(ii) Storing and compacting the waste material
(iii) Eliminating the waste products from the body

(i) Producing bile to aid in the digestion and absorption of fats
(ii) Metabolizing and detoxifying substances in the body
(iii) Regulating blood sugar levels and storing excess energy

(i) Mouth (saliva)
(ii) Stomach (gastric enzymes)
(iii) Small Intestine (pancreatic and intestinal enzymes)
(iv) Liver (bile)

(i) Amylase (breaks down carbohydrates)
(ii) Lipase (breaks down fats)
(iii) Protease (breaks down proteins)
(iv) Cellulase (breaks down cellulose in cassava)

(i) Glucose
(ii) Fatty acids and glycerol
(iii) Amino acids
(iv) Minerals and vitamins

(i) Increased blood pressure
(ii) Retention of water in the body, leading to edema

(i) Provides a good source of carbohydrates from the cassava
(ii) Provides protein from the groundnut soup
(iii) Supplies essential minerals and vitamins
(iv) Helps to maintain body temperature through sweating
(v) Satisfies hunger and provides energy



(4ai) check the table above

(4aii) Mitosis is a type of cell division in which a single cell divides into two daughter cells that are genetically identical to the parent cell. It is responsible for growth, development, and tissue repair in multicellular organisms.

(4b) Parents with blood groups A or B could have an offspring with blood group O if both parents are heterozygous for their blood group alleles. In this case, each parent would contribute one A or B allele and one O allele to the offspring, resulting in the genotype OO, which expresses the blood group O phenotype.

(4c) Genes are involved in the process of evolution through mechanisms such as mutation, natural selection, genetic drift, and gene flow. Mutations introduce genetic variation, which can be acted upon by natural selection, leading to adaptations and changes in allele frequencies over generations, ultimately driving evolutionary change.



(5ai) Competition refers to the struggle between organisms for limited resources such as food, water, mates, or territory.


(I) Intraspecific competition: Competition occurring between members of the same species.
(II) Interspecific competition: Competition occurring between individuals of different species.



(I) Food
(II) Water
(III) Shelter
(IV) Territory
(V) Mates
(VI) Light (for photosynthesis in plants)

(5aiv) Competition influences succession by shaping the composition and abundance of species in an ecosystem. Intense competition among species in the early stages of succession can lead to the dominance of certain species, while others may be excluded. As succession progresses and environmental conditions change, the intensity and outcomes of competition may also change, affecting the trajectory of succession.

(5bi) Structural adaptation refers to physical features or characteristics that enhance an organism’s survival in its environment.



(i) Camouflage
(ii) Mimicry
(iii) Protective coloration
(iv) Structural modifications (e.g., wings, claws, teeth)
(v) Body shape (e.g., streamlined bodies for aquatic animals)
(vi) Specialized appendages (e.g., long necks in giraffes)


(i) DNA fingerprints
(ii) Facial features
(iii) Hair characteristics
(iv) Blood type
(v) Skin color
(vi) Iris patterns

(5e) An example of a plant found in the tropical rainforest is the orchid.



(i) Onion cell
(ii) Sperm cell
(iii) Pollen grain
(iv) Ovum
(v) Guard cell
(vi) Cheek cell

(i) Mitosis
(ii) Meiosis
(iii) Meiosis
(iv) Meiosis
(v) Mitosis
(vi) Mitosis

(i) Diploid
(ii) Haploid
(iii) Haploid
(iv) Haploid
(v) Diploid
(vi) Diploid

Mitosis is a type of cell division in which a single cell divides to produce two genetically identical daughter cells, each with the same number of chromosomes as the original cell.

Parents with blood groups A or B can have an offspring with blood group O if both parents carry the recessive O allele. For example, if one parent has genotype AO (blood group A) and the other has genotype BO (blood group B), there is a 25% chance that the offspring will inherit the O allele from both parents, resulting in the genotype OO, which corresponds to blood group O.

Genes are the foundation of evolution, providing the variation and heredity necessary for natural selection to act upon, resulting in adaptation and change in populations over time. Through genetic variation, mutation, and inheritance, genes allow populations to respond to environmental pressures, driving the evolution of new traits and species. This process shapes the diversity of life on Earth, from the simplest organisms to complex ecosystems, and has led to the incredible range of species that exist today.




  1. Please send the answers here
    Because i didn’t have Whatsapp in my phone please for the grace of God

Leave a Reply

Your comment are Monitored.