There are three types of asexual reproduction. They are binary fission, multiple fission, budding, vegetative propagation and spore formation. Take the example below to understand binary fission in unicellular organisms:
Binary fission: Collect the water in a conical flask from a pond having stagnant water and aquatic plants. Then, put some wheat grains and aquatic plants to it and keep it for three to four days, allowing the wheat grains and the plants to decompose. On the early morning of the fourth day, pour a drop of that water over a glass slide and put a cover-slip on that drop carefully. Now, view under the compound microscope and you will get to see many paramecia performing the binary fission. Some other organisms that perform asexual reproduction using binary fission are Prokaryotes (Bacteria), Protists (Amoeba, Paramoecium, Euglena, etc.) and eukaryotic cell-organelle like mitochondria and chloroplasts. During the process of binary fission, the parent cell is divided to produce two daughter cells that are similar. Binary fission takes place via either mitosis or amitosis. Meanwhile, the axis of fission/division is different in different protists, that is Amoeba divides in any plane as it lacks specific shape and so is known as ‘simple binary fission’. Paramoecium divides by ‘transverse binary fission’ whereas Euglena uses ‘longitudinal binary fission’. Binary fission is normally performed by living organisms under favorable conditions, that is there will be abundant food material available.