All 50 questions from the West African Examinations Council (WAEC) Biology 2016 Objective paper, with the correct answer and a full explanation for each. Free, no signup needed.
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An example of an organism that exists as a colony is
Some organisms are made of similar cells which are joined together and cannot be differentiated from each other. This is known as a colony. Volvox and Pandorina are good examples of colonial organisms.
Gymnosperms bear naked seeds because they lack
Gymnosperms do not bear enclosed seeds. Their seeds are borne on special structures known as cones (they lack an ovary).
DNA formation is associated with
Within the nucleus is a small spherical body called nucleolus and chromatin materials which condense during cell division into chromosomes. The chromosomes are made up of DNA.
Study the diagram carefully (plants A and B) and answer questions 4 and 5. The term that can be used to describe what happened to plant A after seven hours is
This is known as wilting. A plant undergoes wilting (becomes flaccid) when it has lost a great amount of water.
The environmental factors responsible for the condition in plant B are
Wilting may occur if there is little amount of water vapour in the air (low humidity) and when the temperature is high.
Hydra is considered to be at a tissue level of organization of life because it
Hydra is considered to be at a tissue level of organization of life because it has numerous cells that perform different functions.
Study the diagrams below (I and II) and answer question 7 and 8. Which of the following statements about the diagrams is correct?
I=Yeast cell forming buds; II=White blood cell. One of them (yeast) is an organism while the other is a cell.
A decrease in the number of II will result in
As white blood cells serve to protect the body, a decrease in the number of white blood cells will lower the immunity of the body.
Flaccidity in plants is associated with
When the leaves of a plant become limp and flaccid, it is called wilting.
Which of the following substances is not usually present in the urine of a healthy person?
The urine of a healthy person must not contain glucose because as the glomerular filtrate passes into the first convoluted tubule, all amino acids and glucose are reabsorbed into the body by blood capillaries surrounding the tubule.
Muscles act in opposite directions in order to
Muscles act in opposite directions in order to cause a bone to move. For instance, to bend the arm at the elbow, the biceps contract while the triceps relax.
Lateral meristem in flowering plants is found in the
Secondary or lateral meristems, which are found in all woody plants and in some herbaceous ones, consist of the vascular cambium and the cork cambium.
The cells and tissues of the nose, throat, chest diaphragm and lungs form the
The cells and tissues of the nose, throat, chest, diaphragm and lungs form the respiratory system.
The exchange of gases between the environment and the respiratory organs of vertebrates is referred to as
This is simply regarded as breathing. The term respiration may refer to the catabolic process where energy is obtained from glucose.
The maintenance of a constant internal environment in an organism is known as
The maintenance of a constant internal environment in an organism is known as homeostasis.
Which of the following organs is responsible for the production of insulin?
Apart from its role in digestion, the pancreas also secretes hormones (insulin and glucagon) which help in the regulation of blood sugar.
Which of the following actions is not a voluntary action?
Stealing, fighting and cheating are voluntary actions while sneezing is not.
In both dicotyledonous and monocotyledonous plants, the root hairs originate from the
Lateral roots originate endogenously (from the pericycle) while root hairs are simply the outgrowths of epidermal cells.
Which of the following parts of the ear does not contain endolymph?
Tympanum does not contain endolymph. Tympanum is another word for ear drum.
The type of placentation illustrated in the diagram below is:
The diagram represents basal placentation. In basal placentation, the ovules are attached to the base of a syncarpous ovary.
The steps below are involved in the testing of a leaf for starch. Study them carefully and answer questions 21 and 22. I. Decolorize leaf II. Dip decolorized leaf in warm water III. Place leaf in boiling water IV. Add iodine solution. The correct order for the test is
The correct order is III → I → II → IV (Place leaf in boiling water, then decolorize, then dip in warm water, then add iodine solution).
The best time to pluck the leaf for the experiment is
This is to ensure that the leaf has already photosynthesized.
In which of the plant tissues are guard cells located?
Guard cells are located in the epidermis. It must be remembered that guard cells are the only epidermal cells that contain chloroplasts.
The association between two organisms in which one of the organism gains and the other loses is referred to as
The type of association in which one organism gains and suffers harm is known as parasitism. The organism that gains is known as the parasite while the one that loses is known as the host.
The function of the villi in the alimentary canal is to
The function of the villi in the alimentary canal is to increase the surface area for absorption.
Which of the following structures is not an organ of the digestive system?
Oesophagus, pancreas and stomach are parts of the digestive system while the kidney serves excretory roles.
The diagram below shows the effect of nitrate on water bodies. Study it carefully and answer question 27 to 29. The source of nitrates in the part labeled I is the
The source of nitrates in the soil may be from excessive use of fertilizers.
The phenomenon in the diagram is termed
The phenomenon is known as eutrophication.
Another cause that could lead to phenomenon in the diagram is
Dumping of sewage may also result in excessive algal growth which may clog up our water ways.
In ecology, a community refers to
It refers to groups of different organisms living in a habitat. Note that when only organisms of a particular species are considered, we are describing population not community.
The direction of wind is determined by
The wind vane is used to determine the direction of wind while anemometer measures the speed of the wind.
Food webs are complex because
A food web is a complex feeding relationship consisting of interrelated food chains.
Special modifications which enable an organism to survive in its habitats known as
Special modifications which enable an organism to survive in its habitat are known as adaptation. Note that the modification may be structural, functional or behavioural.
Which of the following relationships does not involve two organisms?
Saprophytism involves only one organism. In saprophytism, the organism obtains its nutrient from dead and decaying organic matter.
Overcrowding in a population does not result in
Overcrowding may result in migration, competition and/or death.
A pandemic is an outbreak of diseases that A. is confined to a tow B. is widespread C. will not spread D. has limited spread
A pandemic is an outbreak of diseases that is widespread. Endemic disease, on the other hand, is peculiar to a particular area or region.
The rational and prudent use of natural resources is known as?
The rational and prudent use of natural resources is known as conservation.
Which of the following natural resources cannot be conserved?
Since the rate at which air is used cannot be regulated, it cannot be conserved. Recall that 'renewability' and being able to be conserved are two different things.
Which of the following actions support conservation? To
Protection of endangered species is one of the steps in the conservation of wild life.
A noticeable physical appearance of individuals of the same species is called
This is known as morphological variation. The difference in the ways in which the body functions constitutes physiological variation.
A blend of inherited and acquired characteristics shows
Inherited characteristics come from gene while acquired characteristics come from the environment. This is why it is said that the phenotype of an organism depends on gene and environment.
A Cross between two parents produced four offspring with blood groups AB, BB, BO AO What is the blood group of their parents? A. AA and BO B. BB and AO C. AB and BO D. AB,and AO
A cross between AB and BO will produce AB, BB, BO and AO.
A sick baby was successfully transfused with blood from the father who has blood group AB, what is the group of the sick baby?
Although AB is a universal recipient, it can only donate to another AB. So, for the father whose blood group is AB to successfully donate to a baby, the blood group of the baby must also be AB.
The illustration below represents a cross between a colour blind male and a normal female. Study it carefully and answer questions 44 and 45. What is the genotypic ratio of carrier female to normal males in the cross?
The two females in the diagram are carriers while the two males are normal. Then, carrier female: normal male = 2:2 = 1:1.
Which of the genotypes are carriers of colour blindness?
As explained, only the two females (I & II) are carriers of colour blindness. The two males (III & IV) are normal.
Scientists who study genetics are known as
Scientists who study genetics are known as geneticists.
Which of the following scientists did not contribute to the development of genetics?
The contribution of Felix Durjadin is in the Cell Theory. He was a French biologist who discovered that the cell was made up of living substance (which he called protoplasm).
Which of the following terms is associated with natural selection?
Survival of the fittest is associated with natural selection.
In which of the following insects is group instinct not displayed?
Ants, honeybees and termites are social or group insects while cockroaches are not.
The inability of an organism to adapt to its habitat can lead to
The inability of an organism to adapt to its habitat can lead to extinction.
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