Post-UTME key terms

The process by which green plants use sunlight, water and carbon dioxide to make glucose and release oxygen. It occurs mainly in the chloroplasts of leaf cells.

The green pigment in plant chloroplasts that absorbs light energy for photosynthesis. It absorbs red and blue light but reflects green light, giving leaves their colour.

The breakdown of glucose in living cells to release energy, carbon dioxide and water. Aerobic respiration needs oxygen; anaerobic respiration occurs without oxygen and yields less energy.

The movement of water molecules through a semi-permeable membrane from a region of higher water concentration to one of lower water concentration, without using energy.

The net movement of particles from a region of higher concentration to a region of lower concentration, driven by their random motion. It needs no energy input.

Movement of substances across a cell membrane against a concentration gradient, using energy from ATP. Root hair cells absorb mineral salts this way.

A protein that speeds up a specific biochemical reaction by lowering its activation energy. Enzymes are denatured by high temperature or extreme pH.

The amount of a substance containing as many particles as there are atoms in 12 g of carbon-12, namely 6.02 x 10^23 particles. It links mass, molar mass and number of particles.

The mass of one mole of a substance in grams per mole. It is numerically equal to the relative molecular mass and is used to convert mass to moles.

The number of particles (atoms, ions or molecules) in one mole of a substance, approximately 6.02 x 10^23 per mole. It is used in particle-count calculations.

A substance that increases the rate of a chemical reaction without being used up. It provides an alternative pathway with lower activation energy and is unchanged at the end.

The minimum energy colliding particles need before a reaction can occur. Catalysts lower this energy, so more collisions become successful and the rate increases.

The decomposition of an electrolyte by passing direct current through it. Positive ions move to the cathode and negative ions to the anode, where products are discharged.

A substance that conducts electricity when molten or dissolved in water because it contains free-moving ions. Examples include sodium chloride solution and dilute sulphuric acid.

The rate of change of displacement with time, a vector quantity with both magnitude and direction. It differs from speed, which has magnitude only.

The rate of change of velocity with time, measured in metres per second squared. A body accelerates when its speed, direction, or both change.

Any push or pull that changes or tends to change a body's state of rest or motion. It is measured in newtons and is a vector quantity.

A physical quantity having both magnitude and direction, such as displacement, velocity and force. Vectors are added using the parallelogram or triangle rule.

The bending of light as it passes from one medium to another of different optical density. It happens because the speed of light changes between the media.

The ratio of the speed of light in a vacuum to its speed in a given medium. It measures how strongly a medium bends light entering it.

The current through a conductor is directly proportional to the potential difference across it, provided temperature stays constant. It gives the relation V = IR.

The opposition a conductor offers to the flow of electric current, measured in ohms. It depends on the material, length, cross-sectional area and temperature of the conductor.

The quantity of a good or service consumers are willing and able to buy at a given price over a period. Demand normally falls as price rises.

The quantity of a good or service producers are willing and able to offer for sale at a given price over a period. Supply normally rises as price rises.

The price at which the quantity demanded equals the quantity supplied, so there is neither surplus nor shortage. It is also called the market-clearing price.

The value of the next best alternative forgone when a choice is made. It underlies the economic problem of allocating scarce resources among competing wants.

The condition in which available resources are insufficient to satisfy all human wants. It is the fundamental economic problem that forces choices and rationing.

A sustained rise in the general price level of goods and services over time, which reduces the purchasing power of money. It is commonly measured by the consumer price index.

A system of government in which power is constitutionally shared between a central government and component states or regions, each with defined areas of authority.

The division of government authority among the legislature, executive and judiciary so that no single organ holds excessive power. Each branch checks the others.

The body of fundamental rules and principles by which a state is governed, defining the powers of government and the rights of citizens. It may be written or unwritten.

The principle that everyone, including government officials, is subject to the law and accountable before ordinary courts. It opposes arbitrary exercise of power.

A serious drama in which a noble protagonist suffers downfall through a flaw or fate, arousing pity and fear in the audience. Examples include Shakespeare's Macbeth.

A speech in which a character, alone on stage, reveals private thoughts and feelings to the audience. It exposes motive that other characters cannot hear.

A situation in a play where the audience knows something important that a character does not, creating tension or humour. It depends on the gap in knowledge.

The obligatory annual alms in Islam, paid on qualifying wealth above a minimum threshold and distributed to specified categories of needy people. It is one of the five pillars.

Fasting from dawn to sunset during the month of Ramadan, abstaining from food, drink and other lawful pleasures. It is one of the five pillars of Islam.

A visible sign of inward grace instituted by Christ and administered by the Church, such as baptism and Holy Communion. Most Christian traditions recognise them as means of grace.

In Christian teaching, the unearned favour and help God gives to people for their salvation and sanctification. It is received through faith rather than earned by works.

The practice of growing different crops in sequence on the same land to maintain soil fertility and break pest and disease cycles. Legumes often restore nitrogen.

The conversion of atmospheric nitrogen into compounds plants can absorb, carried out by bacteria in root nodules of legumes and by some free-living soil bacteria.

The wearing away and removal of the fertile topsoil by wind, water or poor farming practices. It reduces land productivity and can be checked by terracing and cover crops.

The accounting principle that every transaction has two equal effects, a debit and a credit, recorded in separate accounts. It keeps the accounting equation balanced.

A statement listing the debit and credit balances of all ledger accounts to test whether total debits equal total credits. It detects arithmetic errors but not all mistakes.

A financial statement showing a business's assets, liabilities and capital at a particular date. Assets must equal liabilities plus capital.