Which discovery supported the endosymbiotic theory?

a.)dna in mitochondria

b.)dna in the cell nucleus

c.)dna in ribosomes

d.)dna in the cytoplasm

The right answer is A.) DNA in mitochondria .

Eukaryotic cells, with their many intracellular organelles, have long been considered progeny of prokaryotes that would have become more complex as a result of genetic mutations. But from the 1960s, biologist Lynn Margulis proposed an alternative explanation that was first received coldly by the scientific community. His endosymbiotic theory, proposed in a more formal way in a 1981 book, proposes that eukaryotic cells as we know them today would be the result of a series of symbiotic associations with different prokaryotes.

Mitochondria and chloroplasts also have their own DNA that is not trapped in a nucleus, which is also the case with prokaryotes. However, the proteins encoded by this DNA do not cover all mitochondrial proteins. The prokaryote is thought to have lost some genes to the nucleus of the cell, a process known as "endosymbiotic gene transfer". For this reason, mitochondria and chloroplasts are now host-dependent for the synthesis of most of their components.

protein synthesis is an example of feedback mechanism which in homeostasis

the cell theory states that all living things including animals, as well as plants, are made of cells.