A type of white blood cell that plays a key role in the immune system, particularly in defending against bacterial infections.

A coenzyme involved in redox reactions, playing a key role in metabolism and energy production in cells.

A coenzyme similar to NAD, involved in anabolic reactions and the production of energy in cells.

Describing species that leave the nest soon after hatching, such as many bird species.

The study of birds’ nests, including their construction, function, and the behavior of birds that build them.

Referring to species, organisms, or characteristics that are black or dark in color, often used in biological classifications.

A compound containing the ion NO2-, often produced by bacteria in the nitrogen cycle and associated with pollution in water.

A genus of bacteria involved in the oxidation of nitrite to nitrate as part of the nitrogen cycle.

A chemical element (atomic number 7) that makes up about 78% of Earth’s atmosphere and is essential for life, especially in amino acids and proteins.

The process by which certain bacteria and archaea convert atmospheric nitrogen (N2) into a form usable by plants, such as ammonia (NH3).