Final answer:
The origin of eukaryotic cells is hypothesized to involve a process called endosymbiosis, in which a larger cell engulfed a smaller cell that eventually became an organelle. This process led to the development of organelles such as mitochondria and plastids. The transition from prokaryotic to eukaryotic cells involved steps such as membrane proliferation, loss of a cell wall, and evolution of a cytoskeleton.
Step-by-step explanation:
The hypothesized sequence of chemical and biological events that preceded the origin of eukaryotic cells is still a topic of debate among scientists. However, the most widely supported hypothesis is the endosymbiotic theory, which suggests that eukaryotic cells evolved from prokaryotic cells through a process of endosymbiosis. This theory proposes that a larger cell engulfed a smaller cell, with the smaller cell eventually becoming an organelle within the larger cell.
The endosymbiotic theory explains the presence of organelles such as mitochondria and plastids in eukaryotic cells. Mitochondria originated from an endosymbiotic event involving the engulfment of an aerobic bacterium, while plastids (such as chloroplasts) likely originated from an endosymbiotic event involving the engulfment of a photosynthetic bacterium.
Overall, the transition from prokaryotic to eukaryotic cells involved a series of events including membrane proliferation, the loss of a cell wall, the evolution of a cytoskeleton, and the acquisition of organelles through endosymbiosis.