Which type of organisms reproduces through the division of one cell to form the entire organism?

Unicellular organisms reproduce by a process called binary fission, wherein a single cell divides into two identical daughter cells. This method of reproduction allows the entire organism to be formed from just one cell, effectively creating a new and independent organism. Unicellular organisms include bacteria, protozoa, and some algae, which carry out all necessary functions for survival and reproduction within that single cell.

The question pertains specifically to organisms that can generate a whole new individual merely from the division of one existing cell, which is characteristic of unicellular life forms. Such reproduction is efficient for their survival in various environments, allowing for rapid population growth under favorable conditions. The other organism types—multicellular, colonial, and prokaryotic—do not reproduce in the same straightforward manner of a single cell giving rise to a complete organism. Multicellular organisms consist of many cells that work together, colonial organisms involve groups of cells that may be interconnected but do not function as a single cell, and while prokaryotic organisms include unicellular entities, the specific context here emphasizes the act of a single cell forming a new organism.