WAEC Biology 2008 past questions
Ten questions from the 2008 WAEC Biology paper, with answers and explanations. We hold 66 questions from this paper, and the Skolra app has all of them.
WAEC Biology 2008 questions and answers
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1.Which of the following processes is not an example of a reflex ac ion?
- ARapid withdrawal of the hand from a very hot object
- BSudden sneezing when dust particles enter the nostrils
- CBlinking of the eye when a fast-moving object approaches
- DWriting one's full name on a piece of paperCorrect
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Answer: D
A reflex action is a rapid, automatic, involuntary response to a stimulus that does not require conscious thought from the cerebral cortex — it is mediated through a reflex arc. Sneezing, hand withdrawal from heat, and eye blinking are all involuntary protective reflexes. Writing one's name, however, is a voluntary action that requires conscious initiation, coordination, and learned motor skill from the cerebrum. It is not automatic or immediate, and it is not mediated by a simple reflex arc. Voluntary actions depend on higher brain centres and can be inhibited or initiated at will.
- A
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2.Which of the following actions is note function of adrenaline? It increases
- ARate of breathing
- BHeart rate
- CThe rate of peristalsisCorrect
- DBlood sugar level
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Answer: C
Adrenaline (epinephrine) is the 'fight-or-flight' hormone secreted by the adrenal medulla. It increases heart rate, breathing rate, blood sugar level (by stimulating glycogenolysis in the liver), and blood flow to the muscles, while dilating the bronchioles. However, adrenaline inhibits the digestive system — it decreases peristalsis by relaxing smooth muscle in the gut wall, diverting blood away from the viscera and toward skeletal muscles. Increasing the rate of peristalsis is a function of the parasympathetic nervous system, which is antagonistic to the actions of adrenaline.
- A
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3.Carbon dioxide is carried in the plasma
- AAs dissolved carbon dioxide gas only
- BMainly as carbaminohaemoglobin
- CMainly as bicarbonate ionsCorrect
- DMainly as carbonic acid molecules
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Answer: C
About 70% of carbon dioxide in the blood is transported in the plasma as bicarbonate ions (HCO₃⁻), formed when CO₂ combines with water inside red blood cells to produce carbonic acid (H₂CO₃), which then dissociates into bicarbonate and hydrogen ions. Approximately 23% is carried bound to haemoglobin as carbaminohaemoglobin, and only about 7% is dissolved directly as CO₂ gas. Carbonic acid itself is a transient intermediate and does not persist in significant quantities. Bicarbonate transport is therefore the dominant mechanism for CO₂ carriage in the blood.
- A
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4.Which of the following diseases is commonly observed in human males and is sex-linked?
- Asickle-cell anaemia
- Bdiabetes mellitus
- Ckwashiorkor
- DhaemophiliaCorrect
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Answer: D
Haemophilia is a sex-linked (X-linked recessive) blood clotting disorder. Because the gene encoding clotting factor VIII (haemophilia A) or factor IX (haemophilia B) is on the X chromosome, males (XY) who inherit one defective allele express the disease, whereas females (XX) are usually only carriers. Sickle-cell anaemia and diabetes mellitus are autosomal conditions, and kwashiorkor is a nutritional deficiency disease — none of these are sex-linked.
- A
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5.
(a) What are hormones?
(b) In a tabular form, state four differences between nervous coordination and hormonal coordination in humans.
(c) State three effects each of: (i) Over-secretion (ii) Under-secretion of thyroxin on mammals.
(d) Make a diagram 10 - 12cm long of the reflex arc and label fully.
- AReduced body temperature and mental sluggishness
- BDecreased heart rate and low blood pressure
- CStunted growth and cretinism in young animals
- DIncreased metabolic rate and loss of body weightCorrect
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Answer: D
Over-secretion of thyroxin causes hyperthyroidism, which leads to an abnormally elevated metabolic rate, resulting in rapid weight loss despite increased appetite, elevated heart rate, nervousness, and exophthalmos (bulging eyes) in humans. Under-secretion produces hypothyroidism — characterised by lethargy, weight gain, and intolerance to cold — and in young animals causes cretinism, a form of stunted physical and mental development. Reduced heart rate and low body temperature are features of under-secretion, not over-secretion. Thyroxin is produced by the thyroid gland in the neck.
- A
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6.
Specimen A: Pride of Barbados flower
Specimen B: Pod of Pride of Barbados
Specimen C: Cock
Specimen H: Tomato fruit
Specimen J: Gloriosa superba leaf & stem with tendrils
Specimen K: Bryophllum leaf
Specimen L: Onion bulbStudy carefully Specimens H, J, K, and L and use them to answer the following question:
(a) (i) Make a drawing 8-10cm long of the longitudinal section of specimen H and label fully.
(ii) What type of fruit is specimen H?
(ii) State two other examples of the type of fruit to wnich specimen H belongs.
(iv) Is specimen H a true fruit or a false fruit?
(v) Give one reason for your answer in a(iv) above.
(vi) State the food classes present in specimen H.
(b)(i) State one(1) feature common to specimens J, K and L.
(ii) State two observable characteristic features each of specimens J, K and L.
(iii) State the mode of vegetative propagation of specimens K and L.
(c) State the biological significance of specimens K.
- ALegume
- BBerryCorrect
- CPome
- DDrupe
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Answer: B
The tomato (Lycopersicon esculentum) is classified as a berry, a fleshy simple fruit that develops entirely from a single flower's ovary wall (pericarp). True berries have seeds embedded in the fleshy mesocarp and endocarp, which is characteristic of the tomato. A drupe has a stony endocarp (e.g., mango), a legume is a dry dehiscent fruit from a single carpel (e.g., bean), and a pome has a fleshy receptacle surrounding the core (e.g., apple). The tomato is also a true fruit because it develops solely from the fertilised ovary.
- A
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7.Which of the following characters is not an example of discontinuous variation?
- Apresence or absence of a widow's peak
- Bbody weightCorrect
- Cability to roll the tongue
- DABO blood groups
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Answer: B
Body weight is an example of continuous variation — it is influenced by many genes acting together (polygenic inheritance) as well as by diet and lifestyle, and individuals show a smooth range of values with no distinct categories. Discontinuous variation produces discrete, non-overlapping categories as seen in blood groups (A, B, AB, O), tongue rolling (roller/non-roller), and widow's peak (present/absent). Body weight cannot be neatly sorted into separate groups, making it the exception.
- A
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8.
(a) Explain the following modes of nutrition which occur in plants:
(i)Autotrophic
(ii) Chemosynthetic
(iii) Carnivorous(b) Give one example each of a plant which undergoes the modes of nutrition listed in (a) above.
(c) (i) Describe three ways by which nitrogen is added to the soil for plant use.
(ii) State two ways by which nitrogen is lost from the soil.
- ASpirogyra
- BNitrobacterCorrect
- CEuglena
- DPitcher plant
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Answer: B
Chemosynthetic nutrition is carried out by certain bacteria that oxidise inorganic compounds to obtain energy for synthesising organic molecules from carbon dioxide, without using sunlight. Nitrobacter is a classic example — it oxidises nitrite (NO₂⁻) to nitrate (NO₃⁻) and uses the released energy to fix carbon dioxide. Euglena and Spirogyra are photosynthetic autotrophs. The pitcher plant is a carnivorous plant that supplements its nutrition by trapping and digesting insects. Nitrobacter is a key organism in the nitrogen cycle, converting nitrite to nitrate available for plant uptake.
- A
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9.The process by which flowers produce fruit without the process of fertilization is called
- Aparthenogenesis
- Bapomixis
- Cpollination
- DparthenocarpyCorrect
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Answer: D
Parthenocarpy is the development of a fruit from an unfertilized ovary, so no viable seeds are formed. It differs from apomixis, which involves seed formation without fertilization. Common examples include seedless bananas, seedless grapes, and some varieties of tomatoes. Parthenocarpy can occur naturally or be induced artificially by hormones such as auxins.
- A
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10.Primary growth in plants is brought about by the activity of the
- ACork cambium
- BVascular cambium
- CApical meristemCorrect
- DLateral meristem
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Answer: C
Primary growth refers to elongation of the plant body in the apical (tip) direction and is brought about by the apical meristems located at the tips of roots and shoots. These meristematic cells undergo rapid mitotic division, producing new cells that elongate and differentiate to form the primary plant body. Secondary growth, which increases girth, is brought about by lateral meristems — specifically the vascular cambium (produces secondary xylem and phloem) and the cork cambium (produces the bark). Only the apical meristem is responsible for the increase in length that constitutes primary growth.
- A
The questions come from past JAMB, WAEC and NECO papers. We use software to help write the answer options and explanations, and every answer is checked twice before it goes on the site. How we check
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Practise all 66 questions we hold from the 2008 paper, on a timed CBT screen
Every question has the answer and an explanation, in the Skolra app.