BECE Basic Science
Past Questions

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**The reasoning** Living things share seven key characteristics that define life: **MRGREN** (Movement, Respiration, Growth, Reproduction, Excretion, Nutrition, Sensitivity). These are biological processes carried out by organisms to survive and continue their species. - **Growth** (A) ✓ All living things increase in size and complexity - **Reproduction** (B) ✓ Living things produce offspring - **Respiration** (D) ✓ Living things break down food to release energy - **Erosion** (C) ✗ This is a *geological process* where wind, water, or ice wears away rocks and soil over time. It has nothing to do with biology! **Why the wrong options tempt you** If you're rushing, Growth, Reproduction, and Respiration all *sound* scientific and important. Your brain might gloss over "Erosion" because it's also a process you've studied in Geography. But erosion affects non-living landscapes, not organisms. **Quick takeaway** Remember: **Living things carry out life processes; erosion is what the environment does to rocks and land.** If the characteristic doesn't involve an organism actively doing something biological, it's not a sign of life!

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**The reasoning** Matter exists in three fundamental forms based on how tightly its particles are packed and how freely they move: 1. **Solid** – particles are tightly packed, fixed in position (like ice, wood, or stone) 2. **Liquid** – particles are close but can slide past each other (like water, oil) 3. **Gas** – particles are far apart and move freely (like air, steam) This is called the **states of matter** or **phases of matter**. Temperature and pressure can change one state to another (ice melts to water, water boils to steam). **Why the wrong options tempt you** **B (Hot, warm, cold)** – These describe *temperature*, not states of matter. Temperature *affects* states, but it's not a state itself. **C (Big, medium, small)** – These describe *size*, which has nothing to do with how matter is structured. **D (Hard, soft, smooth)** – These are *textures* or properties that materials can have, but not scientific classifications of matter's states. **Quick takeaway** Remember: **states of matter describe HOW particles arrange themselves** (fixed, flowing, or free), not how something feels, its size, or its temperature.

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**The reasoning** Matter exists in different physical forms based on how tightly its particles are packed and how they move. The three fundamental states are: 1. **Solid** — particles packed tightly, fixed shape (like ice, wood, metal) 2. **Liquid** — particles loosely connected, takes shape of container (like water, oil) 3. **Gas** — particles spread far apart, fills entire space (like air, steam) This is a foundational concept in Chemistry and Physics. Everything around you fits into one of these three states (plus plasma, which you'll learn later). **Why the wrong options tempt you** **B) Hot, warm, cold** — These describe *temperature*, not states of matter. The trick is that temperature can *change* the state (heating ice → water → steam), but they're not the states themselves. **C) Big, medium, small** — This describes *size*, which has nothing to do with matter's physical form. **D) Hard, soft, smooth** — These describe *texture* or how something feels, not the scientific classification of matter. **Quick takeaway** Remember: **SLG = States, not feelings** — Solid, Liquid, Gas are scientific states of matter; everything else describes properties or conditions of matter.

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**The reasoning** Air is a **mixture** because it contains multiple substances (nitrogen ~78%, oxygen ~21%, carbon dioxide, water vapor, argon, etc.) that are *physically combined* but not chemically bonded together. The key principle: **Mixtures** have components that keep their individual properties and can be separated by physical means (like fractional distillation). Each gas in air behaves independently — the oxygen doesn't chemically react with the nitrogen just sitting there. Compare this to a **compound** like water (H₂O), where hydrogen and oxygen are *chemically bonded* in fixed ratios and you can't just filter them apart. **Why the wrong options tempt you** - **Element (B)**: You might think "air is one thing" — but elements are pure substances made of one type of atom (like gold or oxygen alone). - **Compound (C)**: Tricky! Air *contains* compounds (CO₂, H₂O vapor), but air itself isn't bonded in fixed ratios. - **Pure substance (D)**: Air's composition varies by location (humid vs. dry air, polluted vs. clean) — that variable composition screams "mixture." **Quick takeaway** If you can separate it without breaking chemical bonds, it's a mixture — air is just gases chilling together, not married by chemistry.

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**The reasoning** Magnets work through a property called **ferromagnetism** — the ability of certain materials to be strongly attracted to magnetic fields. Iron, nickel, and cobalt are the main ferromagnetic materials. Their atoms have unpaired electrons that create tiny magnetic fields. When a magnet comes close, these atomic magnets align, and the material gets pulled toward the magnet. Iron is the most common ferromagnetic material you'll encounter, which is why magnets stick to iron nails, steel doors, and metal cans. **Why the wrong options tempt you** - **Wood, glass, and plastic** are all non-magnetic materials. They might tempt you if you're thinking "solid objects attract each other," but attraction requires specific atomic properties, not just being solid. These materials have paired electrons that cancel out magnetic effects. **Quick takeaway** Remember: **Magnets only attract ferromagnetic materials — iron, nickel, and cobalt** — because their atoms can align with magnetic fields. If it's not one of these metals (or their alloys like steel), a magnet won't pull it!

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Mammals have hair, give birth to live young and produce milk. Lion is a mammal.

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Photosynthesis: plants use sunlight, CO₂ and water to make glucose.

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Water boils at 100°C at standard atmospheric pressure.

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Earth orbits the sun once every 365.25 days.

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Coal is a fossil fuel — non-renewable. Solar, wind and hydro are renewable.

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Adult humans have 206 bones. Babies are born with about 270 which fuse with age.

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Plants take in CO₂ and release O₂ as a byproduct of photosynthesis.

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Gravity pulls objects toward the centre of the earth — about 9.8 m/s² near the surface.