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

Does a bacterial cell possess a nucleus?

1. Yes, always

2. No, it does not

3. Only in certain conditions

4. Only in multicellular forms

The correct answer is: No, it does not

Bacterial cells do not possess a nucleus, which is a distinguishing feature between prokaryotic and eukaryotic cells. In prokaryotic organisms, such as bacteria, the genetic material is not enclosed within a membrane-bound nucleus; instead, it is located in a region called the nucleoid. This structure is not separated from the rest of the cell by a membrane, which is typical in eukaryotic cells where the nucleus is well-defined. Additionally, the absence of a nucleus in bacteria is part of their simpler cell structure, which includes other unique features such as peptidoglycan cell walls and the lack of membrane-bound organelles. This fundamental difference in cellular organization is crucial for understanding the classification and biology of living organisms. The other options suggest conditions or structures that do not apply to bacterial cells, reinforcing that they consistently lack a nucleus.