How does an amoeba reproduce?

 Amoeba can reproduce both sexually and asexually

Most of the time, Amoeba proteus reproduces asexually by splitting one cell into two cells, a process called “Binary Fission”. Just before it reproduces, Amoeba proteus retracts most of its pseudopods and rounds up into a ball.

After replicating its genetic material (DNA) in the nucleus, the original nucleus of the Amoeba divides to form two daughter nuclei by the process of Karyokinesis. In this process, the long DNA molecules condense into chromosomes (rod-liked shape) to facilitate the separation.

After the nucleus has divided into two, the process of Cytokinesis takes place in which the cytoplasm in the mother cell pinches in and divides into two daughter cells. This leads to the formation of the two daughter Amoebae cell, having a nucleus and its own cell cytoplasm and organelles. Usually, the entire process may last anywhere from 30 minutes to an hour.

Amoeba reproduction

[In this figure] Two ways of amoeba reproduction: Binary fission and Multiple fission.
Most of the time, amoebas reproduce by the binary fission. When the environment is turning harsh, amoebas adapt to the multiple fission to increase the chance to survive.

There is another rare way for Amoeba to reproduce, called Encystment or Multiple Fission.

When amoeba senses the environment become unfavorable (eg. lack of nutrients, too acidic or too much bright light), it withdraws its pseudopodia and releases a protective coat (called a cyst) made of a chitin-like substance to cover its cell membrane. This cyst is able to survive in much harsher conditions. At the same time, mitosis occurs many times inside the cyst, producing more than two daughter cells. When the cyst wall ruptures (when the condition turns favorable), these daughter cells are then released to become several new amoebas.

When the environment of habitation becomes extremely unfavorable, Amoebas will reproduce through spores. This sexual reproduction can create genetic diversity and increase its chance to survive in harsh conditions.

Extended read:

facts about amoeba

Facts about Amoeba

This article covers