All 50 questions from the West African Examinations Council (WAEC) Biology 2017 Objective paper, with the correct answer and a full explanation for each. Free, no signup needed.
Advertisement
Which of the following groups of animals do not possess a nervous system?
Porifera (sponges) do not have nervous, digestive or circulatory systems. Instead, they rely on a constant water flow through their bodies to obtain food, oxygen and to remove wastes.
The structural similarities in Paramecium and Euglena are in the
Both Paramecium and Euglena have a blunt anterior and pointed posterior. Their locomotory structures differ (Paramecium uses cilia while Euglena uses a whip-like flagellum), and only Paramecium has micro/mega nuclei.
Which of the following organisms cannot exist freely on its own?
Chlamydomonas, Amoeba and Paramecium are free-living organisms, while Plasmodium is parasitic and cannot exist freely on its own.
The Arthropod in the diagram is not an insect because it
Insects have six legs (three pairs); a spider is not an insect as it has eight legs (four pairs) and no wings.
Which of the following cell organelles is the site for the production of ATP?
The mitochondrion (also known as the power house of the cell) is the site of production of energy/ATP.
An example of osmosis in plants is the
Absorption of water from the soil by the root is by osmosis (PAWO - Plant Absorb Water by Osmosis).
The organism that can carry out both autotrophic and heterotrophic modes of nutrition is
Euglena can carry out both autotrophic and heterotrophic modes of nutrition. When there is light, it photosynthesizes; it is also able to carry out holozoic feeding in the absence of sunlight, since it has a gullet to ingest food particles.
The diagram represents the bones of the
The diagram represents the bones of the lower arm (ulna and radius).
Which of the labelled parts articulates with the head of the trochlea to form a hinge joint?
Part labelled II is the sigmoid notch which articulates with the trochlea of the humerus to form the elbow joint.
The labelled part that provides surface for the attachment of the triceps is
Part labelled III is the olecranon process, which provides attachment for the triceps.
The diagram below illustrates the transverse section of a
This is the diagram of a dicotyledonous stem transverse section, based on the arrangement of vascular bundles. Note: you can guess options A and B (root diagrams) out as the absence of root hairs makes it neither a monocot nor dicot root.
Which of the following actions does not occur during exhalation in man?
It is during inhalation that the diaphragm contracts and becomes flattened. During exhalation, the diaphragm relaxes and assumes its dome shape.
Which of the following substances is found in the part labelled II only?
Blood cells and plasma proteins (such as prothrombin and fibrinogen) are too big to pass through the glomerulus, so they remain in the blood.
The part which contains lowest concentration of urea is labelled
Part labelled III is the efferent arteriole from the glomerulus. Of all the indicated parts, III has the lowest concentration of urea.
Which of the following substances is greater in concentration in the part labelled IV when compared to the part labelled I?
Part IV (collecting duct) has a greater concentration of urea than part I (Bowman's capsule).
Deamination of amino acids in the liver produces
Deamination of amino acids in the liver produces urea. Note that every excess amino acid, the carboxyl part is converted to other food classes while the amino part is converted to urea.
Which of the following glands also serves as an exocrine gland?
Pancreas has both the exocrine and the endocrine roles. Its exocrine role is to produce digestive enzymes such as lipase, amylopsin and trypsin. Its endocrine role is to produce the hormones insulin and glucagon.
Which of the following sequences is the correct route of the transmission of impulses along a reflex arc?
The pathway of a reflex arc can be summarized as: Stimulus → Receptor → Sensory neurone → Intermediate neurone → Motor neurone → Effector.
When viewing an object that is close to the human eye, the
When viewing near objects: (i) the ciliary muscles contract and become thicker (ii) the suspensory ligament slackens (iii) the lens become fat and more convex.
The part labelled I is the
The part labelled 'I' is the acrosome, while the part labelled 'II' is the tail.
The function of the part labelled II is to
The tail (labelled II) helps the sperm to swim forward.
Which of the following types of placentation is not common amongst syncarpous pistils?
Marginal placentation is not common among syncarpous pistils. Note that in marginal placentation, the ovules are arranged in a single row at the margin of the ovary.
The complex energy-rich organic matter which living organisms need for life is
The complex energy-rich organic matter which living organisms need for life is food. You may think water also fits the description, however, note that the part "energy-rich organic matter" has betrayed water. Water is not organic; it is inorganic. Also, the calorific value of water is zero.
Which of the following processes are associated with photosynthesis? I. Energy from sunlight is absorbed II. Carbon dioxide is evolved III. Oxygen is given off IV. Glucose is synthesized.
During photosynthesis, CO2 is not evolved. Instead, it is used up! By-product of photosynthesis is O2. 6CO2+6H2O→C6H12O6+6O2. So I, III and IV are correct (energy absorbed, oxygen given off, glucose synthesized), but II (CO2 evolved) is incorrect.
Which of the following function is associated with calcium in plants?
Calcium aids in the formation of cell wall.
The dentition belongs to a
The dentition belongs to man. The total number of teeth in the jaw of an animal is obtained by multiplying the number of teeth in the dental formula by 2. For a man, the dental formula gives a total of 32 teeth.
The function of the teeth labelled X is for
The teeth labelled X is canine. Canine is used for tearing flesh and for catching prey (tearing and grasping).
The teeth which are absent in the young of the organism are labelled
W=Incisors, X=Canine, Y=Premolar, Z=Molar. The first type of teeth possessed by young humans is known as milk teeth, which may number up to twenty; milk teeth comprise incisors, canines and premolars. Molars (Z) are absent — the permanent teeth, which comprise incisors, canines, premolar and molar, only grow after the milk teeth have fallen off.
The number of individuals that the environment can support over a long period of time is its
The carrying capacity is defined as the number of individuals that a particular environment can support over a long period of time.
A good site for secondary succession would be
A good site for secondary succession must be one that has been previously colonized (e.g. a land that has just had forest fire), unlike sand dunes and bare rock which are typical sites for primary succession.
A population which exceeds its carrying capacity and then collapses is represented graphically by a
A population which exceeds its carrying capacity and then collapses is represented graphically by a bell-shaped curve.
The natural dwelling place of an organism is called
The naturally dwelling place of an organism is called its habitat. Note that the exact position and its role in a habitat is known as the ecological niche of the organism.
Which of the following ecological factors will result in food shortage?
Drought refers to a long period of little or no rain. Drought causes food shortage.
Soil permeability refers to
Soil permeability refers to how easily water passes through the soil. How much water rises up a given sample of soil is a function of soil capillarity.
Which of the following groups of organisms do not have members that can be called autotrophs?
Fungi are heterotrophic. They are not able to manufacture their own food.
Which of the following pyramids gives the most accurate picture of the relationships between the organisms at the various trophic levels in a food chain?
Pyramid of energy is defined as the amount of energy present in the living organisms at the different trophic levels of a food chain — it gives the most accurate picture of these relationships.
Which of the following statements is not associated with pyramids of energy?
The numbers of organisms at different trophic levels can be represented by the pyramid of number, not pyramid of energy.
Which of the following materials is not easily biodegradable?
Non-biodegradable substances are those that cannot be broken down into simple harmless substances by living organisms, e.g. glass, stone, plastic, etc. Paper, cotton, hides and skin are biodegradable while polythene is non-biodegradable.
Which of the following pairs of organisms is in a mutualistic relationship?
The sea anemone attaches itself to the shell containing the hermit crab. The sea anemone eats pieces of food left by the hermit crab and in turn protects the crab. This is a good example of mutualism.
The establishment of game reserves and parks is a method of
The establishment of game reserves and parks is an effective method for conserving natural resources.
Which of the following practices is not used in conserving water?
Deforestation does not conserve water in any way.
Which of the following resources cannot be renewed?
Petroleum is not renewable. Air, food crop and soil are all renewable resources.
The type of variation illustrated above is
The ability to roll one's tongue is a discontinuous variation, as one is only either able to roll the tongue or not; there is no intermediate.
Which of the following characters is not a morphological variation?
Morphological variation deals with forms and structures while physiological variation deals with how the body functions. The ability to roll the tongue is a physiological variation.
An apple plant can produce sexually and asexually and it has 40 chromosomes in its leaf cells. How many chromosomes would be in each gamete and somatic cell?
Since leaf cells are somatic cells, the number of chromosomes in the somatic cell is 40. Always, the number of chromosomes in the gamete is half that in the somatic cell. Then, the gamete will contain 20 chromosomes.
Assuming that A is the gene for normal skin colour and is dominant, while a is the gene for albinism and is recessive, what is the likely genotype of the couple which had 50% normal and 50% albino offspring?
Thus, only a cross between Aa and aa can produce 50% albino and 50% normal. Don't forget that A is dominant over a.
Which of the following statements is true about mutation?
Mutation is the sudden change in the genetic make-up of an organism, so genotype is involved.
One of the structural adaptations of mammals for movement on land is the development of the
The pentadactyl limb arrangement enhances movement on land for mammals.
Which of the following traits is not characteristic of social insects?
All members of social insects must not be identical. There must be differences both structurally and functionally. The occurrence of division of labour among the members further buttresses this.
The gradual cumulative, adaptive and heritable changes in an organism over a long period of time resulting in new species is called
The gradual, cumulative, adaptive and heritable changes in an organism over a long period of time resulting in new species is known as organic evolution.
Advertisement
…and/or go further with premium services and No Ads.