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Plants are eukaryotes. A typical photosynthetic leaf cell has a cell nucleus, mitochondria, chloroplasts, and a cell wall outside its cell membrane. A root cell need not have chloroplasts; the plant's parts specialize for different functions. Plants perform cellular respiration as well as photosynthesis. See OpenStax Biology 2e, 4.3: plant cell organization.

A plastid is an organelle of the lineage that includes chloroplasts. A chloroplast is a photosynthetic plastid; the terms are not interchangeable because some plastids are nonphotosynthetic. Endosymbiotic theory connects plastid origins to cyanobacteria, while endosymbiotic gene transfer and organelle protein import explain genetic and functional integration with the host.

A prokaryote is an organism whose biological cells lack a membrane-bounded cell nucleus. The DNA of its chromosomes occupies a nucleoid within the cytoplasm. Bacteria and archaea have this cellular organization. Both contain ribosomes that perform biological translation and a selective cell membrane; neither is a bag of unorganized chemicals. See OpenStax Biology 2e, 4.2: prokaryotic organization.

The word prokaryotic describes organization, not a single exclusive clade. Grouping bacteria and archaea by the absence of a cell nucleus is useful for comparing biological cells, but does not establish that they share a more recent ancestor with one another than either does with eukaryotes. See three-domain system and two-domain system for the different ancestry models.

Prokaryotic does not mean membrane-free. Cyanobacteria contain internal thylakoid membranes for oxygenic photosynthesis, despite lacking chloroplasts and a cell nucleus. Many prokaryotes have circular chromosomes, but circular shape and a single chromosome are not defining requirements. See OpenStax Biology 2e, 22.2: bacterial and archaeal structures.

A thylakoid is a flattened membrane-bounded compartment. In a chloroplast, its membrane contains the machinery for light-dependent reactions, including chlorophyll. Stacks of thylakoids pack membrane area into a small space within the chloroplast; the light-dependent reactions schematic simplifies this architecture.