What type of cells are larger, more complex, and contain membrane-bound organelles?

Eukaryotic cells are characterized by their larger size and complexity compared to prokaryotic cells. One of the defining features of eukaryotic cells is the presence of membrane-bound organelles, such as the nucleus, mitochondria, endoplasmic reticulum, and Golgi apparatus. These organelles allow for compartmentalization of various cellular processes, leading to more efficient cellular function and higher organization within the cell.

This structural complexity is essential for supporting various life processes, including metabolism, energy production, and genetic regulation. In contrast, prokaryotic cells, found in organisms like bacteria and archaea, are generally smaller and simpler, lacking these membrane-bound organelles and having their genetic material not enclosed in a nucleus.

While single-celled organisms and cellular aggregates can both refer to various forms of eukaryotic and prokaryotic life, the focus of this question is on the structural and organizational differences between eukaryotic and prokaryotic cells. Thus, the defining characteristic of eukaryotic cells being larger, more complex, and containing membrane-bound organelles makes this the correct answer.