Microscopic plants, including algae and cyanobacteria, that float in aquatic environments and form the base of the food chain.

A plant-derived sterol that is chemically similar to cholesterol and found in the cell membranes of plants.

A toxic substance produced by plants, often as a defense mechanism against herbivores.

In biochemistry, the abbreviation for inorganic phosphate, a molecule involved in energy transfer in cells.

A unit of capacitance, equal to one trillionth of a farad (10^-12 F).

A unit of mass equal to one trillionth of a gram (10^-12 g).

A unit of volume equal to one trillionth of a liter (10^-12 L).

A unit of amount of substance, equal to one trillionth of a mole (10^-12 mol).

A unit of time equal to one trillionth of a second (10^-12 s).

An extinct genus of hominids, including species such as Homo erectus, regarded as an early ancestor of humans.