Which of the following structures does not contain membrane-bound organelles?

Bacterial cells do not contain membrane-bound organelles. In cellular biology, cells are typically classified into two main categories: prokaryotic and eukaryotic. Bacterial cells are classified as prokaryotic cells, which are simpler in structure and lack the defined compartments that membrane-bound organelles provide.

In contrast, eukaryotic cells, which include both animal and plant cells, have complex internal structures that include organelles such as the nucleus, mitochondria, and endoplasmic reticulum, all surrounded by membranes. This compartmentalization allows eukaryotic cells to perform various functions more efficiently and is absent in bacterial cells.

So, in the context of the question, the accurate distinction is that bacterial cells have a more simplistic structure and operate without the internal compartments that characterize eukaryotic cells.