Final answer:
Endosymbiosis of a cell with a cyanobacterium would result in a eukaryotic cell that can make its own food.
Step-by-step explanation:
According to the endosymbiotic theory, the endosymbiosis of a cell with a cyanobacterium would result in a eukaryotic cell that can make its own food. In this theory, it is believed that mitochondria and chloroplasts, which are organelles found in eukaryotic cells, were once free-living prokaryotes that were engulfed by the ancestral eukaryotic cell. Cyanobacteria, specifically, are known for their ability to carry out photosynthesis, producing their own food.
Learn more about Endosymbiotic theory and the origin of eukaryotic cells