BECE 2003 Integrated Science Objective Questions and Answers

Solution: Filtration is the process that separates an insoluble solid from a liquid by passing the mixture through a filter medium that traps the solid particles.

Solution: Diffusion is the movement of molecules from an area of high concentration to low concentration, allowing perfume scent to spread throughout the room.

Solution: Solidification of water into ice is a physical change because it is reversible and does not alter the chemical composition of water.

Solution: Atoms of the same element have identical protons (defining the element), electrons (in neutral atoms), and thus identical chemical properties.

Solution: The joule is the SI unit for energy, named after James Prescott Joule, and measures work/energy transfer.

Solution: Water at height has potential energy, converted to kinetic energy as it flows down, then to electrical energy via turbines and generators.

Solution: Closer magnetic field lines indicate stronger fields, while wider spacing indicates weaker fields.

Solution: Warm, moist air contacts the cold bottle, causing water vapor to condense into droplets on the cooler surface.

Solution: Density = mass/volume. Volume = 35 cm³ - 20 cm³ = 15 cm³; Density = 35g / 15cm³ ≈ 2.33 g/cm³ (rounded to 2.3 g/cm³).

Solution: The banana peel reduces friction between the shoe and ground, causing loss of traction and slipping.

Solution: In a first-class lever (e.g., seesaw), the fulcrum (pivot) is positioned between the effort and load.

Solution: Work = force × distance; 75 J = 50 N × height; Height = 75 J / 50 N = 1.5 m.

Solution: Carnivores are animals that primarily consume the flesh/meat of other animals.

Solution: Gills extract dissolved oxygen from water and expel carbon dioxide, enabling underwater respiration.

Solution: Thorns are modified structures that deter herbivores and protect the plant from physical damage.

Solution: Not all living things move (e.g., plants), but all reproduce, excrete, and grow.

Solution: Ticks are external parasites that attach to the skin of animals (e.g., cattle) to feed on blood.

Solution: Water loss via evaporation (respiration/sweating) is a major survival challenge for terrestrial mammals.

Solution: Female Anopheles mosquitoes transmit Plasmodium parasites to humans through bites, causing malaria.

Solution: Lime (calcium carbonate) neutralizes acidic soil by reacting with hydrogen ions to raise pH.

Solution: Layer M (topmost) contains lightweight organic matter like decomposed leaves that float on water.

Solution: Layer Q (sand) has large particles with low surface area, resulting in poor water retention.

Solution: Only plants perform photosynthesis, converting CO₂, water, and sunlight into glucose and oxygen.

Solution: Aerobic respiration produces CO₂ and water as waste: C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + energy.

Solution: Lungs expel CO₂ (waste from metabolism) from the blood into exhaled air during respiration.

Solution: Banana (suckers) and ginger (rhizomes) reproduce asexually via vegetative structures; mango uses seeds.

Solution: Respiration occurs in all living cells to release energy (ATP) from nutrients for metabolic processes.

Solution: Yam is a tuber rich in starch (complex carbohydrate), providing energy storage for the plant.

Solution: Lipase enzymes break down fats/oils into fatty acids and glycerol for absorption in the small intestine.

Solution: Germination requires water (to activate enzymes) and optimal temperature; soil is not essential (e.g., hydroponics).

Solution: The pistil (stigma, style, ovary) contains ovules and receives pollen for fertilization in flowering plants.

Solution: Bile emulsifies fats into smaller droplets, increasing surface area for lipase enzymes to act efficiently.

Solution: Bilharzia (schistosomiasis) damages urinary tract blood vessels, causing hematuria (blood in urine).

Solution: Dietary fiber adds bulk to stool, softens it, and stimulates peristalsis for regular bowel movements.

Solution: Measles spreads via airborne respiratory droplets from coughs/sneezes of infected individuals.

Solution: The moon’s synodic cycle (phases) lasts ~28 days, making it visible throughout the month.

Solution: Earth completes one revolution around the sun in 365 days (1 year), defining our calendar.

Solution: A moon (natural satellite) orbits planets; e.g., Earth’s moon orbits our planet.

Solution: Dodder (Cuscuta) is a parasitic plant lacking chlorophyll that derives nutrients from host plants.

Solution: Balanced diets include macronutrients (carbs, proteins, fats) and micronutrients (vitamins/minerals), but table salt (NaCl) is a mineral additive, not a core category.