OCR General Certificate of Secondary Education (GCSE) Biology Practice Exam

What unique feature do prokaryotes possess?

1. Membrane-bound organelles

2. DNA enclosed in a nucleus

3. Small and uncomplicated structure

4. Presence of chloroplasts

The correct answer is: Small and uncomplicated structure

Prokaryotes are characterized by their small and uncomplicated structure, distinguishing them from eukaryotic cells. They typically range between 0.1 to 5 micrometers in size and possess a simpler organization. Prokaryotic cells lack membrane-bound organelles, such as a nucleus, which is a defining feature of eukaryotic cells. Instead, their genetic material is found in a region called the nucleoid and is usually a single circular DNA molecule. This simplicity allows for rapid reproduction and adaptability in various environments. In contrast, membrane-bound organelles and a true nucleus are key features of eukaryotic cells, while the presence of chloroplasts is specific to certain eukaryotes, particularly plants and algae. Hence, the uncomplicated structure of prokaryotes is a fundamental aspect of their biology.