BECE 2008 Integrated Science Objective Questions and Answers

Solution: A metre rule is designed for linear measurements. It measures length effectively (e.g., tables) but cannot measure volume, curved surfaces (like balls), or small diameters requiring precision tools.

Solution: Radiation (infrared waves) transfers heat without a medium. Conduction/convection require matter (solids/fluids), which vacuums lack.

Solution: Mirrors use reflection to redirect light. Dispersion splits light (e.g., prisms), refraction bends it (e.g., lenses), and radiation emits it.

Solution: Striking a bell converts mechanical energy (kinetic force) into sound energy (vibrations). No significant light or potential energy is involved.

Solution: Fuses melt when current exceeds safe limits, breaking the circuit to prevent damage. They do not increase current/heat or prevent shocks directly.

Solution: Iron is ferromagnetic (attracted to magnets). Aluminium, brass, and copper are non-magnetic metals.

Solution: The Sun (fusion) and fireflies (bioluminescence) emit light. The Moon reflects sunlight but produces none.

Solution: Light travels rectilinearly (in straight lines). It can be blocked/absorbed, not all objects are transparent, and reflection depends on surface properties.

Solution: Free electrons in metals move under voltage, enabling conductivity. Neutrons/protons are bound in nuclei, and atoms alone don’t guarantee conductivity.

Solution: Beriberi results from vitamin B₁ (thiamine) deficiency, affecting nerves/heart. Vitamins A, E, K deficiencies cause other issues (e.g., vision, clotting).

Solution: Hairy fruits (e.g., dandelions) have structures that catch wind. Succulent fruits attract animals, bright colors lure eaters, and sticky fruits cling.

Solution: Proteins provide amino acids for tissue building/repair. Carbohydrates/oils supply energy; vitamins regulate metabolism.

Solution: Incisors slice/bite food. Canines tear, molars/premolars grind.

Solution: Xylem vessels move water/minerals upward. Phloem transports sugars; stomata regulate gas exchange; chlorophyll aids photosynthesis.

Solution: The outer ear includes the pinna (visible part) and eardrum. Ossicles/cochlea are inner/middle ear structures.

Solution: The Eustachian tube equalizes pressure between the middle ear and throat. Ampullae/cochela handle balance/sound; the eardrum transmits vibrations.

Solution: The pupil (opening in the iris) contracts/expands to control light entry. The iris adjusts pupil size; the lens focuses; the retina senses light.

Solution: Genetic traits are inherited via reproduction (DNA transfer). Breastfeeding/training/sharing are environmental, not genetic.

Solution: Dissolved air (e.g., oxygen) escapes during boiling, altering taste. Heat absorption/evaporation/steam don’t directly affect taste.

Solution: Hardness increases with mineral content: distilled (pure) < rainwater (low minerals) < tap water (moderate) < seawater (high salts).

Solution: Filtration traps solids (e.g., sand) while liquids pass through. Distillation/evaporation separate solutes; winnowing sorts solids by density.

Solution: Alloys are homogeneous metal mixtures (e.g., brass). Compounds involve chemical bonding; solvents/suspensions are not specific to metals.

Solution: Oil paints dissolve in organic solvents (kerosene, petrol, turpentine) but not in polar water due to "like dissolves like" principle.

Solution: Excess electrons create negative ions (anions). Positive ions lack electrons; neutral atoms have balanced charges; compounds involve multiple elements.

Solution: Carbon dioxide (CO₂) is a pure compound. Air/salt solution/smoke contain multiple components physically mixed.

Solution: Scales form a tough, overlapping armor. Fins aid movement; gills enable breathing; operculum covers/protects gills.

Solution: Hydrogen sulphide (H₂S) is toxic/corrosive. Water vapor, oxygen, and nitrogen are natural, non-polluting air components.

Solution: Bilharzia (schistosomiasis) spreads via water-contacting parasite larvae in slow waters. Cholera/dysentery come from contaminated water; river blindness via flies.

Solution: Leaf shedding (abscission) reduces transpiration, conserving water in droughts. Heat/fire/nutrient loss are not primary reasons.

Solution: Caterpillars (larval insects) are herbivorous pests that parasitize plants by consuming leaves. They do not infect animals.

Solution: The moon’s sidereal orbit (full revolution around Earth) is ~27.3 days, often rounded to 28 days in basic science contexts.

Solution: Acids turn blue litmus red. Bitterness suggests alkalinity (turns red litmus blue); low sugar doesn’t define acidity.

Solution: Potassium’s symbol is K (from Latin *kalium*). N is nitrogen, P is phosphorus, S is sulfur.

Solution: Ductility allows metals to stretch into wires. Malleability permits shaping (e.g., hammering); conductivity/resistivity relate to electricity.

Solution: Drying (dehydration) and frying use heat to remove moisture/kill microbes. Salting uses osmosis; canning uses heat but option IV is not selected.

Solution: Weight is the gravitational force on a mass (F = m × g). It is not energy/work (transfer) or power (rate).

Solution: Valves in veins ensure unidirectional blood flow toward the heart. Arteries/capillaries lack valves; the heart pumps but doesn’t block backflow.

Solution: Cohesion holds like molecules (e.g., water droplets). Adhesion binds different substances; capillary action/surface tension are results of cohesion.

Solution: Absorption transfers nutrients from the intestines to blood. Ingestion is intake; egestion/excretion remove waste.

Solution: Sticking droplets demonstrate adhesion, not capillary action. Capillary action moves liquids through narrow spaces (A, B, C).