BECE 2001 Integrated Science Objective Questions and Answers

Solution: Carbon monoxide is produced by incomplete combustion in domestic fires and is a toxic gas that poses significant health risks.

Solution: Plantain reproduces through suckers, which are shoots emerging from the base of the parent plant and developing into independent plants.

Solution: Oxygen is essential for combustion as it acts as an oxidizing agent in chemical reactions involving burning.

Solution: Petals attract pollinators like insects through bright colors and scents, facilitating cross-pollination.

Solution: Kidneys filter blood to remove urea and other nitrogenous wastes, excreting them as urine.

Solution: The solar system comprises the sun and celestial bodies (planets, moons, etc.) bound by its gravity.

Solution: Bilharzia larvae penetrate human skin during contact with contaminated water, causing infection.

Solution: Brass is a durable alloy primarily composed of copper (∼70%) and zinc (∼30%), used in fittings and instruments.

Solution: Tetanus spores (e.g., from soil) enter through wounds, producing toxins that cause muscle rigidity.

Solution: The pivot (fulcrum) is the fixed point (Q) where the bar rotates, enabling balance.

Solution: Effort (P) is the applied force to lift the load, acting at one end of the lever.

Solution: Tongue (taste), nose (smell), and skin (touch) are sense organs; hair lacks sensory receptors.

Solution: Cotyledons store nutrients (e.g., starch, proteins) to nourish the developing seedling during germination.

Solution: Fertile soil requires macronutrients like nitrogen (growth), phosphorus (energy transfer), calcium (cell walls), and sulfur (protein synthesis).

Solution: Ovens and hair dryers convert electricity to heat via resistors; refrigerators use motors for cooling, not heating.

Solution: The angle of incidence equals reflection. If light makes \( 20^\circ \) with the surface, it makes \( 70^\circ \) with the normal, so reflection is \( 70^\circ \).

Solution: Earth’s tilt (23.5°) and revolution around the sun cause varying solar intensity, creating seasons.

Solution: Cooling a saturated hot solution reduces solubility, causing excess solute (sugar) to crystallize.

Solution: All living things reproduce, respire (release energy), and excrete (remove wastes); not all move (e.g., plants).

Solution: Tendrils (modified stems/leaves) coil around supports, helping climbing plants access sunlight.

Solution: Volume = mass / density = 25.0 g / 2.5 g/cm³ = 10.0 cm³.

Solution: Vitamins (e.g., C, D) are essential micronutrients that support immunity, growth, and disease prevention.

Solution: Flowing water’s kinetic energy spins turbines, converting motion to mechanical energy for electricity.

Solution: The central nervous system (CNS) comprises the brain (command center) and spinal cord (signal pathway).

Solution: Photosynthesis requires CO₂, light, and chlorophyll to produce glucose; oxygen is a byproduct.

Solution: Peas (legumes) host nitrogen-fixing bacteria in root nodules, enriching soil with nitrogen.

Solution: Covered containers block flies (disease vectors) from breeding in or contaminating waste.

Solution: At any instant, half of Earth is illuminated by sunlight (daytime), while the other half is in darkness.

Solution: Bacteria are microscopic, single-celled organisms; others are visible invertebrates.

Solution: Machines simplify work (I) by transmitting force (II); not all have engines (e.g., levers, pulleys).

Solution: The style is part of the pistil (female structure), connecting the stigma to the ovary.

Solution: Water (H₂O) is a compound of hydrogen and oxygen; others are elements.

Solution: A saturated solution holds the maximum solute at a given temperature; excess remains undissolved.

Solution: Cellular respiration releases energy stored as heat (X), alongside water and CO₂.

Solution: Emulsions form when immiscible liquids (e.g., oil, water) mix temporarily via agitation.

Solution: Plasmodium (malaria parasite) infects red blood cells during its lifecycle.

Solution: A zygote is the diploid cell resulting from fertilization, initiating embryonic development.

Solution: Ammeters measure electric current (amperes) and are connected in series in circuits.

Solution: Atomic number = 4 (beryllium); electron configuration (2,2) occupies two shells (K and L).

Solution: Gaps accommodate thermal expansion of rails on hot days, preventing buckling.