Question

What is an endosymbiont? give an example.

Answer 1

Hint: The origin of certain of the cell organelles seen in eukaryotic cells, such as mitochondria and chloroplasts, can be traced back to the endosymbiotic idea. It's an example of a mutually beneficial connection.
Different types of free-living prokaryotes were absorbed inside bigger prokaryotic cells and eventually grew into mitochondria, chloroplasts, and perhaps other organelles, according to this theory.

Complete answer:
Endosymbionts are also known as endobionts. In a mutualistic connection, it refers to a creature living within the body or within the cells of another organism. Endosymbionts can be located inside cells or connected to the cell surface. These organisms develop a symbiotic relationship that benefits both of them.
The roots of legume plants and rhizobia bacteria, for example, are an example of a beneficial interaction between a host and an endosymbiont.
Endosymbiotic theory-
According to the endosymbiotic theory, some cell organelles seen in eukaryotic cells, such as mitochondria and chloroplast, were formerly free-living prokaryotic organisms that began living in a symbiotic relationship with the eukaryotic organism after being absorbed by it.
The fact that mitochondria and chloroplasts both have circular DNA, ribosomes, and are covered by double membranes proves that they were prokaryotic creatures. They have ribosomes of the $$70$$S type, which are similar to those seen in prokaryotes.
Binary fission is a mechanism that occurs in both mitochondria and chloroplast in prokaryotes.
The matrix is the innermost part of mitochondria, whereas the stroma is the innermost section of chloroplasts.
The Svedberg (S) unit is used to represent ribosomes, and it represents the sedimentation rates of various ribosomes during centrifugation.

Note:
It is a unified and widely recognised theory that explains how organelles arose in organisms, distinguishing prokaryotic and eukaryotic species. All organisms emerged from a single common ancestor, according to this view, which is congruent with general evolutionary theory. This predecessor is thought to have evolved from microbes or prokaryotes with a single strand of DNA surrounded by a plasma layer.