Which type of cell lacks a nucleus?

The correct answer is prokaryotic cell, which is characterized by the absence of a nucleus. In prokaryotic cells, such as bacteria, the genetic material is not enclosed within a membrane-bound nucleus. Instead, it is found in a region called the nucleoid, which is not separated from the rest of the cell by any membrane. This structural characteristic is a fundamental difference between prokaryotic cells and eukaryotic cells, which include both plant and animal cells, where the nucleus is a defining feature serving as a protective compartment for the cell's DNA.

Understanding this distinction is critical when studying different types of cells. Eukaryotic cells, which have a nucleus, are typically more complex and make up multicellular organisms, while prokaryotic cells tend to be simpler and are often unicellular organisms.