What is a defining feature of eukaryotic cells?

A defining feature of eukaryotic cells is the presence of a nucleus. Eukaryotic cells are characterized by their complex structure, which includes a well-defined nucleus that houses the cell's genetic material (DNA). This nucleus is surrounded by a nuclear membrane, separating it from the cytoplasm.

In contrast to prokaryotic cells, which lack a nucleus and have their genetic material freely floating within the cell, eukaryotic cells exhibit this compartmentalization, allowing for more complex regulation of gene expression and cell function. The presence of a nucleus is pivotal not only for the storage of DNA but also plays a critical role in processes such as transcription and RNA processing, distinguishing eukaryotic cells in terms of cellular organization and functionality from their prokaryotic counterparts.

In addition to possessing a nucleus, eukaryotic cells often contain other membrane-bound organelles, such as mitochondria, endoplasmic reticulum, and Golgi apparatus, which contribute to their functionality and metabolic processes. Therefore, the presence of a nucleus is not just a defining feature but also a foundational aspect that allows for greater complexity in eukaryotic cell structure and organization.