Final answer:
The term "prokaryote" is considered problematic due to the diversity and complexity of these organisms, such as internal membranous structures and cytoskeletal elements. The exception to the reasons for discarding the term is that some bacteria do not have their genetic material enclosed within a membrane.
Step-by-step explanation:
The question is addressing one of the criticisms of the term "prokaryote" as a designation for organisms that lack a nucleus and other membrane-bound organelles. However, the term is considered problematic by some scientists because it oversimplifies the diversity found within these organisms. For example, some bacteria have internal membranous structures, and many have cytoskeletal elements, suggesting a greater complexity than the term "prokaryote" implies. Although some bacteria do have membranous structures like bacterial microcompartments (BMCs), these bacteria do not have a genetic material enclosed within a membrane like eukaryotes. Therefore, the correct answer to the question, which is the exception that does not support the idea of discarding the term prokaryote, is: 2) Some bacteria have their genetic material enclosed within a membrane. This is not true for prokaryotes as their DNA is located in a region called the nucleoid without a surrounding membrane.