Which of the following is an example of a eukaryotic cell?

Eukaryotic cells are characterized by having a true nucleus enclosed by a membrane and contain various organelles such as mitochondria, endoplasmic reticulum, and Golgi apparatus. An animal cell is a specific example of a eukaryotic cell, as it possesses all these defining characteristics, differentiating it from prokaryotic cells such as bacterial cells, which lack a true nucleus.

Bacterial cells represent prokaryotic life forms and do not have the internal compartmentalization found in eukaryotic cells. A bacterial plasmid is a small, circular piece of DNA found in prokaryotic cells, typically used in genetic engineering, and does not represent a complete cell structure. Viral particles, while they can infect both eukaryotic and prokaryotic cells, are not classified as living cells because they cannot reproduce independently and lack cellular structure and organelles. This context reinforces why an animal cell is the only correct example of a eukaryotic cell among the listed options.