Combined Science key terms

A group of atoms that occurs repeatedly along a polymer molecule.

A sample that reflects the relevant characteristics of the population being studied.

The insoluble solid left on the filter paper after filtration.

A measure of how strongly a component opposes the flow of charge, calculated using $R = V/I$ and measured in ohms ($\Omega$).

A force that opposes motion, such as friction or air resistance.

A component that limits current; a fixed resistor has a resistance that is not adjustable.

The ability to distinguish two points close together as separate points. Higher resolution allows finer detail to be seen.

Chemical reactions in cells that transfer energy from glucose; aerobic respiration releases carbon dioxide and water.

A health problem affecting the airways or lungs and making breathing more difficult.

Apparatus used to measure the rate of respiration, commonly by measuring oxygen uptake.

An enzyme that cuts DNA at particular recognition sequences.

The single force that has the same effect as all the forces acting together on an object.

Using a product again without processing its material into a new product.

A membrane process in which pressure forces water through a partially permeable membrane, separating it from dissolved salts.

The reaction that converts products back into the original reactants, read from right to left in a chemical equation.

A reaction in which products can react to form the original reactants, so the reaction can occur in both directions.

The ratio of the distance travelled by a substance to the distance travelled by the solvent front, both measured from the baseline: $R_f = \frac{\text{distance travelled by substance}}{\text{distance travelled by solvent front}}$.

A small sub-cellular structure where proteins are made.

A rule for finding the magnetic field direction around a straight conductor: point your right thumb along the conventional current, and your curled fingers show the field direction.

A shallow, transparent-bottomed tank used to produce and observe water waves.

The chance that harm will occur, rather than a guarantee that it will occur.

An examination of a procedure to identify hazards, evaluate the risks and choose precautions to reduce harm.

Something that increases the likelihood of developing a disease.

A plant root cell with a long projection that increases its surface area for absorbing water and mineral ions.

A fungal disease of roses that causes purple or black spots on leaves, which often turn yellow and fall early, reducing photosynthesis and growth.

The distance travelled by a substance, measured from the origin to the centre of its spot, divided by the distance travelled by the solvent from the origin. It has no unit.

A bacterial infection spread by swallowing Salmonella bacteria in contaminated food, causing fever, abdominal cramps, vomiting and diarrhoea.