Which reproduction method involves a single-celled organism dividing into two equal cells?

Binary fission is a method of reproduction commonly used by single-celled organisms, such as bacteria. In this process, a single organism replicates its DNA and then divides into two equal parts, resulting in two genetically identical daughter cells. This method allows for rapid population growth under favorable conditions, as one organism can quickly produce two, and then those two can each produce two more, leading to exponential growth.

Other reproduction methods mentioned serve different functions. Conjugation is a form of genetic exchange between organisms, often involving a transfer of DNA but not resulting in the creation of new cells through division. Meiosis, on the other hand, is a specialized type of cell division that results in gametes, with half the number of chromosomes, and is used in sexual reproduction. Bud formation involves an outgrowth from the parent organism, developing into a new organism, but it does not involve equal division of the original cell. Therefore, binary fission is the specifically accurate term for the process where a single-celled organism divides into two equal cells.