BECE 2002 Integrated Science Objective Questions and Answers

Solution: Iron is an element composed solely of iron atoms. Salt (NaCl) is a compound, steel is an alloy (mixture), and water (H₂O) is a compound—all contain multiple types of atoms.

Solution: Ice floats due to lower density than water. For the same mass, ice occupies more volume (option D), while denser substances (B) or heavier masses per volume (C) would sink.

Solution: Gas molecules move faster than liquid molecules due to higher kinetic energy. Solids have ordered molecules (A), are incompressible (B), and liquids lack definite shape (C).

Solution: X represents neutrons (neutral particles in the nucleus), and Y is the nucleus (central part containing protons and neutrons). Shells hold electrons, not labeled here.

Solution: Friction resists relative motion between surfaces. Gravity pulls objects downward, tension acts in stretched materials, and weight is gravitational force.

Solution: Braking converts kinetic energy (motion) into heat via friction. No potential energy (stored) is involved here.

Solution: Work = Force × Distance = 50 N × 6 m = 300 J. Other options miscalculate the formula.

Solution: Work requires force and displacement. Walking with a load (A) and rising from a chair (B) involve displacement. Pushing a static wall (C) and sitting (D) lack displacement.

Solution: Food energy is chemical, stored in molecular bonds (e.g., carbohydrates). Electrostatic, solar, and thermal energies are unrelated.

Solution: Efficiency = 100% - Energy loss = 100% - 10% = 90%. Losses reduce efficiency proportionally.

Solution: In standard circuit diagrams, a switch (component II) controls current flow by opening/closing the circuit.

Solution: Component V (likely a bulb) is a lamp converting electrical energy to light. Batteries supply energy, meters measure.

Solution: Component IV (likely a resistor) limits current to protect components. Switches close circuits; batteries supply energy.

Solution: Elephantiasis (lymphatic filariasis) is transmitted by mosquito bites. Cholera/dysentery are waterborne; blindness isn’t directly spread.

Solution: Bilharzia (schistosomiasis) involves water snails as intermediate hosts for parasitic larvae. Humans are definitive hosts.

Solution: Part IV (gills) extracts dissolved oxygen from water for respiration. Fins control movement; scales protect.

Solution: Part V (caudal fin/tail) propels and steers the fish. Pectoral/pelvic fins aid balancing; swim bladder controls depth.

Solution: Valid food chains start with producers (grass). A follows: producer → herbivore (grasshopper) → carnivores (toad, snake, crow). Others are illogical (e.g., B starts with consumer).

Solution: Tapeworm larvae in undercooked meat infect humans. Guinea/hook/thread worms spread via water/soil, not meat.

Solution: All living things respond (I), respire (II), and grow (IV). Not all move locationally (e.g., plants—III is false).

Solution: Sugarcane is propagated via stem cuttings (containing nodes for new growth). Seeds (corn) are not typical; leaves/suckers aren’t used.

Solution: Glycogen (stored in liver/muscles) is the carbohydrate reserve. Glucose circulates; amino/fatty acids are from proteins/fats.

Solution: Lungs expel CO₂ during exhalation. Kidneys remove urea; skin/mouth release minimal gases.

Solution: Proteins break down into amino acids for absorption. Glycerol is from fats; glycogen is a carb; peptides are intermediates.

Solution: Plasma (90% water) carries cells/nutrients. Hemoglobin is in RBCs; platelets are cell fragments; cytoplasm is cellular.

Solution: Ileum (small intestine) has villi for nutrient absorption. Stomach digests; liver processes; kidneys filter blood.

Solution: Ear canal channels sound to the eardrum. Lobe is external; eardrum vibrates; semicircular canals manage balance.

Solution: Excretion eliminates metabolic wastes (e.g., urea). Egestion removes undigested food; perspiration is sweat; respiration is gas exchange.

Solution: Mammals are viviparous—internal fertilization and development. External fertilization occurs in fish/amphibians; self-fertilization is rare.

Solution: Photosynthesis produces oxygen as a byproduct. CO₂ is absorbed; carbon monoxide/nitrogen are not involved.

Solution: Clay has the smallest particles (<0.002 mm), enabling high water retention. Sand is coarse; loam is a mixture; humus is organic.

Solution: Clay’s fine particles and narrow pores maximize water retention. Sand/gravel drain quickly; loam is moderate.

Solution: Earthworms decompose organic matter into humus. Insects/rats contribute less directly; wind erodes soil.

Solution: Quarrying generates airborne dust from rock crushing. Waste/smoke/acid are minor compared to particulate pollution.

Solution: Ringworm is a fungal infection (e.g., Trichophyton). Bacteria cause boils; insects/worms don’t cause ringworm.

Solution: Airborne diseases (e.g., TB) are controlled by reducing spitting (III) and covering food (IV). I prevents waterborne diseases; II targets fecal-oral transmission.

Solution: Inadequate heating allows bacteria to survive and multiply, spoiling soup. Salt content (A), evaporation (B), and condensation (D) are irrelevant.

Solution: Humidity quantifies air’s water vapor. Clouds are vapor masses; dew is condensed vapor; temperature is heat intensity.

Solution: The Sun is a star (fusion-powered). Earth is a planet; Moon is a satellite; Milky Way is a galaxy.

Solution: Pluto (dwarf planet) has the largest orbit (farthest from the Sun). Jupiter is largest but closer; Mars/Venus are inner planets.