Answer:
eukaryotic cells have a membrane-bound nucleus and prokaryotic cells do not.
Explanation:
Eukaryotes have many membrane-bound organelles while prokaryotes have no membrane-bound organelles.
You are correct the answer is nuclear fusion
Answer:
Mitochodaria is present in majority of cells and plastid is present only in in few.
Explanation:
Endosymbiosis theory explain that mitochondria and plastids arose from bacteria through engulfing by larger cells because mitochondria and plastids contain different DNA than cell nuclei.
Mitochondria were acquired before than plastids because mitochondria is present in majority of eukaryotic cell and some cell have plastids with mitochondria.This explain that after the endosymbiosis of mitochondria some cells did endosymbiosis with photosynthetic bacteria to acquire plastid.