Paramecium aurelia in the final stage of cell division. 400x, DIC

Most paramecia undergo cell division, binary fission, dividing the cell into two new cells that rapidly grow and develop into the new organisms. This process can happen up to three times a day if the conditions are right. While paramicia usually reproduce asexually, when food supplies are low, they may reproduce through a form of conjugation, the transfer of genetic material through cell-to-cell contact. Two paramecia fuse together, including the nuclei within each cell, after which they divide into four separate parts. In this division process, the organisms undergoes meiosis, and the diploid micronucleus divides twice, resulting in four haploid micronclei. This combination of two different genetic individuals and mixing of chromosomes is the basis of sexual reproduction. Progeny from conjugation must reproduce asexually 50 times before they are able to perform conjugation, after which their biological clocks are restarted, allowing for conjugation. Death follows after about 100 generations, because of prot