What structures are unique to eukaryotic cells?

Eukaryotic cells are distinguished by several unique structures that are not found in prokaryotic cells. The presence of a nucleus is a defining feature of eukaryotic cells, as it houses the cell's genetic material and is surrounded by a nuclear membrane. This compartmentalization allows for more complex regulation of gene expression and cellular processes.

Additionally, eukaryotic cells possess organelles such as the endoplasmic reticulum, which is involved in protein and lipid synthesis; the Golgi apparatus, which modifies, sorts, and packages proteins; mitochondria that serve as the powerhouses of the cell by producing ATP through cellular respiration; and lysosomes, which contain enzymes for digestion of macromolecules. These organelles contribute to the overall functionality and complexity of eukaryotic cells, enabling them to maintain homeostasis and carry out various biochemical pathways effectively.

In contrast, the other options include structures that may be present in certain cell types but do not uniquely define eukaryotic cells. While plasma membranes and ribosomes are found in both eukaryotic and prokaryotic cells, cell walls and chloroplasts are typically associated with plants and some protists, and flagella and cilia are present in both types