Definition

Noun 1. A taxonomic group (kingdom) comprising prokaryotic organisms: "Prokayotae" is an informal taxonomic name for a major biological division. It encompasses all organisms whose cells lack a membrane-bound nucleus and other complex organelles. This group includes bacteria, cyanobacteria (blue-green algae), and archaea.

Usage Notes

• The term "Prokayotae" is considered informal and outdated in modern scientific classification. It was used before the fundamental distinction between Bacteria and Archaea was fully recognized.
• The formal, universally accepted term for organisms without a cell nucleus is prokaryote (singular) or prokaryotes (plural).
• "Prokayotae" is primarily encountered in historical biological texts or as an example of older classification systems.

Examples

• In older biology textbooks, the kingdom Prokayotae was listed alongside Plantae and Animalia.
• The informal grouping Prokayotae included diverse single-celled life forms like and .

Advanced Usage

• "The concept of Prokayotae": Refers to the historical idea of grouping all prokaryotic life into a single kingdom.
  • The concept of Prokayotae has been superseded by the three-domain system.

Variants and Related Words

• Prokaryote (n): The correct, modern term for any organism within the former Prokayotae group (e.g., a bacterial cell is a prokaryote).
• Prokaryotic (adj): Describing the cellular characteristics of these organisms (e.g., prokaryotic DNA, prokaryotic cell structure).
• Monera (n): Another historical kingdom name that is synonymous with Prokayotae.

Synonyms

• Prokaryotes (preferred modern term)
• Monera (historical synonym)

Antonyms

• Eukaryote / Eukarya: Organisms whose cells contain a membrane-bound nucleus and organelles (e.g., plants, animals, fungi, protists).

Noun

1. prokaryotic bacteria and blue-green algae and various primitive pathogens; because of lack of consensus on how to divide the organisms into phyla informal names are used for the major divisions