Question

d. Chemoheterotroph 12. Which of the following statements is NOT true about primary endosymbiosis, and the evolution of Domain Eukarya? a. It involved a larger ancestral cell engulfing a smaller prokaryote and forming a symbiotic relationship. It likely happened twice during the evolution of eukaryotes: once for the formation of mitochondria and once for the formation of chloroplasts. Evidence that primary endosymbiosis occurred includes the fact that mitochondria and plastids have a double-membrane system. d. During the process of primary endosymbiosis, the complete genome of the engulfed cell was eventually transferred to the nucleus of the larger cell. to wommer, beuh! senelles plasma membrane somer circuler ONA 1. for enzymatic produe A i transformation absorb forican DNA enviroment con nopkarphe & virus suvirus packs bacheta into new viru.

Answer 1

The theory holds that the eukaryote mitochodrion evolved from a small, autotrophic bacterium that was engulfed by a larger primitive, heterotrophic, eukaryotic cell. This eukaryotic cell arose when an anaerobic prokaryote (unable to use oxygen for energy) lost its cell wall. The more flexible membrane underneath then began to grow and fold in on itself which, in turn, led to the formation of a nucleus and other internal membranes.

The endosymbiotic formation of true eukaryotic cell takes place in the following way.
1) The primitive eukaryotic cell was also eventually able to eat prokaryotes, which is a marked improvement to absorbing small molecules from its environment
2) The process of endosymbiosis started when the eukaryote engulphed but did not digest a autotrophic bacterium.
3) The eukaryote then began a mutually beneficial (symbiotic) relationship with it, whereby the eukaryote provided protection and nutrients to the prokaryote, and in return, the prokaryotic endosymbiont provided additional energy to its eukaryotic host through its respiratory cellular machinary.
4) The relationship became permanent over time completing primary endosymbiosis as the endosymbiont lost some genes it used for independent life and transferred others to the eukaryote's nucleus.
The symbiont thus, became dependent on the host cell for organic molecules and inorganic compounds. The genes of the repiratory machinary became a mitochondrion.
Endosymbiotic theory hypothesizes the origin of chloroplasts similarly, where chloroplasts a eukaryote with mitochondria engulfs a photosynthetic cyanobacteruim in a symbiotic relationship ending in the chloroplast organelle.
According to 4th statement, some of the genes of endosymbiont were retained by it for its independent life, remaining are transferred to the nucleus of eukaryote.

Thus, the statement given in option, "d" is not TRUE about primary endosymbiosis.
Hence, option, "d" is the correct answer.