Key terms & definitions

Physical activation of the body, shown by changes such as a faster heart rate, increased breathing and sweating.

A response or activity of a living organism that can be observed or measured, such as heartbeat or breathing.

The study of how the body and its organs work.

An antimicrobial substance produced by some plants following infection, particularly in response to bacteria or fungi.

A biological extraction method in which plants absorb metal ions from soil through their roots and concentrate them in their tissues.

The uptake of metal compounds from soil by plants; this is the uptake stage used in phytomining.

A biological extraction method in which plants absorb metal compounds, after which the plants are harvested and burned to produce metal-containing ash.

A method of extracting metals using plants to absorb metal compounds, followed by harvesting and burning the plants and processing the ash.

Microscopic organisms that drift in water and use sunlight to photosynthesise, forming the base of many marine food chains.

The constant ratio of a circle's circumference to its diameter, written $\pi$.

A family of programmable microcontrollers made by Microchip Technology, used to control electronic products and systems.

A programming system using PIC microcontrollers supplied with firmware that allows programs to be downloaded using a simple cable connection.

Automated placement of electronic components at programmed positions on a printed circuit board.

An automated process in which a robotic machine selects electronic components and positions them at programmed locations on a printed circuit board.

Gathering outside a workplace to publicise a dispute and persuade others not to enter or work there.

A trillionth of a unit, equal to $10^{-12}$ of that unit.

A unit of length equal to $10^{-12}$ metres. Its symbol is pm.

A chart using repeated pictures or symbols to represent quantities, with a key giving the value of each symbol.

A diagram that represents frequencies using repeated pictures or symbols whose values are given by a key.

A display in which symbols represent frequencies, with a key stating the value of one whole symbol.

A diagram in which symbols represent numbers of observations, using a key to show the value of each symbol.

A taste for scenery valued for its striking, irregular or romantic appearance, including ruined buildings.

Policing provided by separate organisations with limited coordination rather than by one unified force.

Payment for each item an employee produces.

A function defined using different rules for different parts of its domain.

A system of payment in which workers earn according to how much they produce.

A circle divided into sectors whose sizes show the proportions of categories within a whole.

A circular chart divided into sectors so that each sector's angle is proportional to the frequency of its category.

A circular diagram divided into sectors whose angles show the proportions of the total in different categories.

A circular chart divided into sectors whose angles represent each category's share of the total.