OCR GCSE Combined Science A key terms

The nerves outside the brain and spinal cord that connect the central nervous system to the rest of the body.

An object that produces its own magnetic field and retains its magnetism without an external magnetic field.

At right angles: making an angle of $90^\circ$.

A consequence for an individual, such as a change in their health or choices.

Choosing treatment, including a drug and its dose, using information about an individual's genetic make-up.

The industry that uses hydrocarbons from petroleum to manufacture chemicals and materials.

A numerical measure related to the concentration of hydrogen ions in a solution: lower pH means greater hydrogen ion concentration.

A white blood cell that engulfs and digests pathogens.

The process in which a cell engulfs a pathogen and digests it using enzymes.

An organism’s observable characteristics, resulting from its genetic information and its environment.

Plant transport tissue that carries dissolved sugars and amino acids to growing and storage tissues.

An electronic instrument that uses a probe placed in a solution to measure its pH and display a numerical reading.

Harmful air pollution formed when sunlight drives reactions between pollutants, including oxides of nitrogen.

The process in which plants and other photosynthetic organisms use light energy to make glucose from carbon dioxide and water.

A structure that blocks pathogens from entering the body or helps remove them.

A change in which no new substance forms; the chemical identity of the particles remains unchanged.

A characteristic that can be observed or measured without changing a substance into a different substance, such as its melting point.

The use of plants to absorb metal ions through their roots and concentrate them in plant material, which is harvested and processed to recover the metal.

A treatment that contains no active drug, used as a comparison in some clinical trials.

The straw-coloured liquid component of blood that carries dissolved substances and suspends blood cells and platelets.

A small circular DNA molecule found in bacteria, separate from their main chromosome.

A change in shape or size that is not completely reversed when the deforming forces are removed, leaving a permanent change.

A horizontal section of a graph where the measured quantity no longer changes.

A small cell fragment in the blood that helps form a clot at a damaged blood vessel.

A small compass whose north-seeking needle points in the direction of the magnetic field at its position.

An atomic model in which negatively charged electrons are embedded in a ball of positive charge.

Which of two terminals is positive and which is negative.