The following statements about prokaryotes are true except:

• A. Their genetic materials are enclosed in a nuclear membrane.
• B. They are relatively small.
• C. Their genes are dedicated to essential functions only.
• D. They lack autonomous organelles.

Answer: (A)

Prokaryotes do not have a membrane-bound nucleus; their genetic material sits in the nucleoid region inside the cell, not enclosed by a nuclear membrane. That makes the statement about a nuclear membrane false for prokaryotes, so it’s the exception. In contrast, prokaryotes are generally small and lack autonomous organelles such as mitochondria or chloroplasts, reflecting their simpler cellular organization. Their genomes are compact and primarily geared toward essential cellular functions, though they can also carry nonessential genes on plasmids, rather than being limited to strictly essential genes.