Which of the following are prokaryotic cells and which are eukaryotic cells? Amoeba cell, Bacterium cell, Human cheek cell, Blue-green algae cell, Onion peel cell.

Prokaryotic cells in this list are bacterium cells and blue-green algae cells (cyanobacteria). Despite the word "algae" in their name, blue-green algae are actually bacteria, not true algae, and they lack a membrane-bound nucleus and other membrane-enclosed organelles. Both bacterial cells and cyanobacteria have their genetic material in a nucleoid region without a nuclear envelope and perform all cellular functions without compartmentalization.

Eukaryotic cells in this list include amoeba cells, human cheek cells, and onion peel cells. Amoeba is a single-celled protist with a well-defined nucleus and membrane-bound organelles. Human cheek cells are epithelial cells from a multicellular animal organism, containing a nucleus, mitochondria, and other eukaryotic features. Onion peel cells are plant cells with a nucleus, cell wall, central vacuole, and all typical plant organelles (though chloroplasts are less abundant in the colorless peel layers). This classification demonstrates how the prokaryotic-eukaryotic distinction cuts across different kingdoms of life—prokaryotes include only bacteria and archaea, while eukaryotes encompass the tremendous diversity of protists, fungi, plants, and animals.