Does the endosymbiosis theory include the nucleus??
Nope, the endosymbiotic theory doesn’t include the nucleus. The nucleus likely arose from infoldings of the plasma membrane, just as with the endoplasmic reticulum and Golgi apparatus. Having a membrane surrounding the DNA was beneficial, and it survived in future generations. The endosymbiotic theory really only focuses on mitochondria and chloroplasts. Sometimes it mentions flagella and cilia, but this has mostly been discredited. Mitochondria have their own ribosomes and DNA, and thus, produce all the materials they need for their own functions. However, through the course of evolution, a number of mitochondrial genes have relocated to the nuclear DNA. Nowadays, then, mitochondria do rely on genes located in the nucleus. In the past, however, mitochondria operated completely of their own accord. The same goes for chloroplasts. Meiosis only occurs in the germline cells of the ovaries and testes to produce ova and sperm. All other cells in the body divide by mitosis.
