endosymbiosis
noun
en·do·sym·bi·o·sis
ˌen-dō-ˌsim-bī-ˈō-səs 
-bē-
-bē-
: symbiosis in which a symbiont dwells within the body of its symbiotic partner
Examples of endosymbiosis in a Sentence
Recent Examples on the Web
In facultative endosymbiosis, the symbiont can live independently, as in the case of nitrogen-fixing Rhizobium bacteria in the root nodules of leguminous plants.
—
Encyclopedia Britannica,
18 June 2026
This primordial gulp, creating a condition known as endosymbiosis (also thought to be the origin story of mitochondria), is believed to have happened just once.
—
Quanta Magazine,
4 May 2026
These experiments show just how delicate the early stages of endosymbiosis are—the initial disadvantage to the host could have led to an unsuccessful match under natural conditions.
—
Barbara A. Perry,
Newsweek,
27 Jan. 2025
This phenomenon of one cell living inside another, called endosymbiosis, has fueled the evolution of complex life.
—
Molly Herring,
WIRED,
26 Jan. 2025
Two of these were formed through a process called endosymbiosis, in which a once free-living organism is incorporated into a cell.
—
John Timmer,
Ars Technica,
11 Apr. 2024
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Encyclopedia Britannica,
18 June 2026
This primordial gulp, creating a condition known as endosymbiosis (also thought to be the origin story of mitochondria), is believed to have happened just once.
—
Quanta Magazine,
4 May 2026
These experiments show just how delicate the early stages of endosymbiosis are—the initial disadvantage to the host could have led to an unsuccessful match under natural conditions.
—
Barbara A. Perry,
Newsweek,
27 Jan. 2025
This phenomenon of one cell living inside another, called endosymbiosis, has fueled the evolution of complex life.
—
Molly Herring,
WIRED,
26 Jan. 2025
Two of these were formed through a process called endosymbiosis, in which a once free-living organism is incorporated into a cell.
—
John Timmer,
Ars Technica,
11 Apr. 2024
Cite this Entry
“Endosymbiosis.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/endosymbiosis. Accessed 3 Jul. 2026.
Copy CitationMedical Definition
endosymbiosis
noun
en·do·sym·bi·o·sis
ˌen-dō-ˌsim-bī-ˈō-səs
-bē-
-bē-
plural endosymbioses
-ˌsēz
: symbiosis in which a symbiotic organism lives within the body of its partner
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