OCR GCSE Biology 2026 – 400 Free Practice Questions to Pass the Exam

Prokaryotic cells are characterized by their simplicity and lack of compartmentalization. One of the defining features of prokaryotes is their absence of a nucleus; instead of having their genetic material contained within a membrane-bound nucleus as seen in eukaryotic cells, prokaryotes have their DNA freely floating in the cytoplasm in a region known as the nucleoid. This fundamental difference highlights the simpler structure of prokaryotic cells, which typically also lack other membrane-bound organelles such as mitochondria or the endoplasmic reticulum. This structural simplicity is a key distinction that defines prokaryotic life forms, including bacteria and archaea, in contrast to the more complex eukaryotic cells found in organisms like plants, animals, and fungi.