WAEC Biology 2023 past questions and answers

The diagram below is an illustration of a mango leaf drawn by a student in a Biology test. The student failed the test. The likely reason why the student failed the test was that the

1. A.labels were wrong and the guidelines were not touching the structures.
2. B.net venation shown were few, rough, not properly drawn and wrongly placed.
3. C.leaf was too tapered at the apex, the leaf stalk was too short and the shape of the leaf was wrong.
4. D.leaf venation should have been parallel and the midrib should be thicker.

The diagram below is an illustration of a mango leaf drawn by a student in a Biology test. The student failed the test. Which other features of the diagram, if shown, would have earned the student more marks? The

1. A.colour and size.
2. B.title and magnification
3. C.habitat and agricultural qualities of leaf.
4. D.spelling of label and length of midrib.

The diagrams below are illustrations of forms in which a particular group of organisms exist. Which group of organisms is illustrated?

1. A.Bacteria
2. B.Viruses
3. C.Fungi
4. D.Protozoa

The diagrams below are illustrations of forms in which a particular group of organisms exist. In which of the illustrated forms does the organism that causes cholera exist?

1. A.II
2. B.III
3. C.IV
4. D.V

Study the list of organisms: I - Hydra, II - Owl, III - Snake, IV - Snail. Arrangement of the organisms in order of increasing complexity is

1. A.I-II-III-IV.
2. B.II-III-I-IV.
3. C.I-IV-III-II.
4. D.IV-III-II-I.

Study the list of organisms: I - Hydra, II - Owl, III - Snake, IV - Snail. The phylum of the organism labelled IV is

1. A.Coelenterata.
2. B.Platyhelminthes
3. C.Mollusca
4. D.Arthropoda.

The diagram below is an illustration of a cell in which photosynthesis takes place. In which of the labelled parts would molecules of water and carbon (IV) oxide combine to form sugar?

1. A.I.
2. B.II.
3. C.III.
4. D.IV.

The diagram below is an illustration of a cell in which photosynthesis takes place. The oxygen gas formed in the cell diffuses out of the cytoplasm into the air spaces through the part labelled

1. A.I.
2. B.II.
3. C.III.
4. D.IV.

An example of a process that involves osmosis is the

1. A.movement of digested food from ileum into blood capillaries.
2. B.translocation of starch from leaves to all parts of a plant.
3. C.reabsorption of food nutrients from the kidney into blood capillaries.
4. D.movement of water from root hairs into cortical cell.

Growth in animals differs from that in plants because growth in

1. A.plants is intercalary.
2. B.animals is apical.
3. C.plants is from within.
4. D.plants is indefinite.

The diagram below is an illustration of a structure in the skeletal system of humans. The illustrated structure is a part of the

1. A.cervical vertebrae.
2. B.axial skeleton.
3. C.axis vertebrae.
4. D.appendicular skeleton.

The diagram below is an illustration of a structure in the skeletal system of humans. An individual was involved in a car accident and the illustrated structure was badly injured. Which of the following structures would most likely be affected?

1. A.Lumbar, eye and teeth
2. B.Ear, brain and hinge joint
3. C.Eye, cerebellum and ear
4. D.Clavicle, tongue and pelvis

The diagram below is an illustration of some structures used for gaseous exchange in humans. The parts labeled I, II, III and IV respectively are

1. A.larynx, bronchus, bronchiole and trachea.
2. B.bronchus, bronchiole, trachea and larynx.
3. C.bronchiole, trachea, bronchus and larynx.
4. D.larynx, trachea, bronchiole and bronchus.

The diagram below is an illustration of some structures used for gaseous exchange in humans. The part labeled III would be found in the

1. A.heart.
2. B.lung.
3. C.kidney.
4. D.sternum.

Which of the following hormones is wrongly paired with its secretory organs?

1. A.Insulin and pancreas.
2. B.Oestrogen and ovary.
3. C.Oxytocin and hypothalamus.
4. D.Adrenalin and kidney.

The eye defect caused by an uneven curvature of the cornea or lens or both is

1. A.myopia
2. B.astigmatism.
3. C.presbyopia.
4. D.hypermetropia.

The androecium in a flowering plant is a collection of

1. A.ovules.
2. B.stamens.
3. C.filaments.
4. D.sperms.

Placentation in fruits is referred to as the

1. A.part of the ovary where the ovules originate and remain till maturity.
2. B.formation of a single carpel joined at the two edges of an ovule.
3. C.arrangement of ovules in the ovary of a flower.
4. D.ovules borne on a central column of tissues in an ovary.

Which of the following processes does not occur during photosynthesis?

1. A.Carbon (IV) oxide is evolved
2. B.Water is split
3. C.Oxygen is evolved
4. D.Energy from sunlight is absorbed

Stunted growth and small yellow leaves in plants are symptoms of the deficiencies of

1. A.sulphur.
2. B.iron.
3. C.magnesium.
4. D.nitrogen.

The structure that its action could result in choking when talking and eating at the same time is

1. A.epiglottis.
2. B.oesophagus.
3. C.liver.
4. D.stomach.

The food substance that would produce the highest amount of energy is

1. A.glucose.
2. B.fat.
3. C.amino acid.
4. D.protein.

Organisms that feed on dead, decaying tissues of other organisms are known as

1. A.parasites.
2. B.autotrophs.
3. C.heterotrophs.
4. D.saprophytes.

The type of nutrition in which organisms take in solid organic materials into their body is

1. A.holozoic.
2. B.symbiotic.
3. C.saprophytic.
4. D.parasite.

The mouthparts of a grasshopper are adapted for

1. A.chewing.
2. B.grinding.
3. C.sucking.
4. D.absorption.

A group of organisms belonging to different species that coexist in the same habitat and interact is referred to as

1. A.population.
2. B.biosphere.
3. C.niche.
4. D.community.

Fishes survive in water mainly because they possess

1. A.streamlined body.
2. B.scales.
3. C.paired fins.
4. D.gills.

Which of the following soil types have a high capillarity?

1. A.Sand and clay
2. B.Silt and clay
3. C.Silt and sand
4. D.Loam and sand

Which of the following organisms would be the producer in a food chain?

1. A.Goat
2. B.Maize
3. C.Man
4. D.Bacterium

The rate of decomposition of dead organisms is faster in the tropical rainforest than in other biomes because

1. A.of consistent cool temperature.
2. B.of the relatively constant daylight.
3. C.there are more plants.
4. D.of availability of moisture.

The diagrams below are illustrations of organisms in a habitat. The feeding relationship between the organisms labelled III and IV in the diagrams is

1. A.mutualism.
2. B.parasitism.
3. C.predation.
4. D.saprophytism.

The diagrams below are illustrations of organisms in a habitat. The producer in the diagrams is

1. A.I because it contains the least amount of energy.
2. B.I because it uses sunlight to manufacture food.
3. C.IV because it is the largest organism in the diagram.
4. D.IV because it is the organism that receives the highest amount of sunlight.

Which of the following activities is against the conservation of natural resources?

1. A.Afforestation
2. B.Deforestation
3. C.Establishment of game reserves.
4. D.Contour ploughing

Use the information below: I - making shoes from crocodile skin; II - making tables with plastic; III - using elephant tusk for decoration; IV - using firewood for cooking. The act that should be encouraged for the conservation of wildlife and forests is

1. A.I.
2. B.II.
3. C.III.
4. D.IV.

In order to avoid some of the acts that would have negative effects on conservation, Government should

1. A.enact and enforce laws towards conservation of resources.
2. B.promote felling of trees without planting new ones.
3. C.encourage indiscriminate killing of wildlife.
4. D.encourage over-utilization of forest resources.

Which of the following characteristics shows discontinuous variation in plants?

1. A.Colour of flower
2. B.Height of plant
3. C.Leaf size
4. D.Fruit size

A Rhesus negative woman may experience stillbirth of the second child that is Rhesus positive because

1. A.the woman is susceptible to diseases during pregnancy.
2. B.the blood of the foetus might clump.
3. C.they have poor circulatory system.
4. D.the foetus is deprived of nourishment.

A sudden change in the genetic composition of an organism is termed

1. A.epistasis.
2. B.linkage.
3. C.mutation.
4. D.variation.

Paternity disputes could be resolved accurately through

1. A.finger printing
2. B.blood group.
3. C.DNA test.
4. D.tongue rolling.

The illustration below is a genetic diagram:
Gametes across the top: E, E. Gametes down the side: E, e.
Row E: I, II
Row e: III, IV
What is the name of the genetic diagram?

1. A.Genetic cross
2. B.Punnett square
3. C.Inheritance diagram
4. D.Genetic square

The illustration below is a genetic diagram:
Gametes across the top: E, E. Gametes down the side: E, e.
Row E: I, II
Row e: III, IV
What do the labels I, II, III and IV respectively represent?

1. A.EE, EE, EE and EE
2. B.Ee, Ee, EE and Ee
3. C.EE, EE, Ee and Ee
4. D.EE, EE, Ee and ee.

The illustration below is a genetic diagram:
Gametes across the top: E, E. Gametes down the side: E, e.
Row E: I, II
Row e: III, IV
The genotypic ratio of the offspring in the genetic diagram is

1. A.1:1.
2. B.1:2:1.
3. C.1:3.
4. D.4:0.

What is the probability that a pregnancy would result in a male child?

1. A.1
2. B.¾
3. C.½
4. D.¼

A vestigial structure in humans is

1. A.gall bladder.
2. B.villus.
3. C.earlobe.
4. D.tail bone.

The following activities are associated with termites except

1. A.nuptial flight.
2. B.communication.
3. C.pollination.
4. D.searching for food.

(a) What is classification of living things?
(b) State four ways each by which the following groups of organisms are of economic importance in their habitats.
(i) fungi; (ii) plants.
(c) Complete the table below by stating five major phyla of the Kingdom Animalia and give one example of each.
Table: Phyla of Kingdom Animalia | Example

(a) Complete the table below.
Table columns: Element | Function in plants | Effect of deficiency in plants
Rows: Iron; Molybdenum; Potassium; Copper; Nitrogen
(b) Name three classes of organic foods which are essential constituents in the diet of a mammal.
(c) State two roles each of the following structures of the digestive system in humans: (i) buccal cavity; (ii) duodenum; (iii) stomach.
(d) Name the end product of adding dilute hydrochloric acid to sucrose.

Relationships I, II, III, IV and V exist among some organisms in an ecosystem.
I: Organism A grows on dead organism B.
II: Organism C feeds on the remnants of food left by organism D without affecting organism D negatively or positively.
III: Organism E provides shelter for organism F while organism F transports organism E towards food.
IV: Organism G kills organism B for food.
V: Organism H feeds on organism J, causing organism J a disease.
Use them to answer questions 3(a) to 3(e).
(a) Name the type of relationship in: I, II, III, IV, V.
(b) In relationship IV, what is the biological term for each of organisms B and G? (i) B; (ii) G.
(c) Name one example each of organisms B to J.
(d)(i) Name the relationship that is most beneficial to the ecosystem.
(ii) Give one reason for the answer in 3(d)(i).
(e)(i) Give two examples of organism A.
(ii) Name the group to which organism A belongs.

(a) Complete the following Punnett squares of a dihybrid cross between two rats. One has black fur (BB) and short tail (tt), the other has brown fur (bb) and long tail (TT).
[A 4 by 4 grid: the corner is marked X, the gametes Bt run across the top and the gametes bT run down the side.]
(b) How many of the offspring will have: (i) black fur and short tail; (ii) brown fur and long tail; (iii) black fur and long tail; (iv) brown fur and short tail.
(c) If there were twenty (20) chromosomes in the leaf cell of a plant, how many chromosomes would be in each of the following cells of the plant? (i) pollen grain (ii) guard cell (iii) ovule (iv) root cell

Section B
(a)(i) What are sense organs?
(ii) Name three sense organs that respond to the stimulus of chemicals.
(b) List three animals each that exhibit the following courtship behaviours. (i) territoriality (ii) pairing
(c)(i) State one similarity between the eggs of toads and the eggs of birds.
(ii) State three differences between the eggs of toads and the eggs of birds.
(d) Complete the table below by listing four organisms involved in the nitrogen cycle and state one role each of the organisms.
(e) Complete the table below by naming two types of heterotrophic modes of nutrition in animals and give two examples each of the organisms that carry out the modes of nutrition.
Table columns: Two modes of heterotrophic nutrition | Two examples of organisms that carry out mode of nutrition