| Size | 1–10 µm | 10–100 µm |
| Nucleus | Absent (nucleoid region) | Present (membrane-bound) |
| Nuclear membrane | Absent | Present (double membrane + pores) |
| DNA structure | Circular, naked (no histones) | Linear, associated with histones |
| Number of chromosomes | Single circular chromosome | Multiple linear chromosomes |
| Plasmids | Present (common) | Absent (rare exceptions in yeast) |
| Ribosomes | 70S (50S + 30S) | 80S cytoplasm (60S + 40S) |
| Organelle ribosomes | N/A | 70S in mitochondria + chloroplasts |
| Membrane-bound organelles | Absent | Present (ER, Golgi, lysosomes, etc.) |
| Mitochondria | Absent (mesosomes compensate) | Present |
| Chloroplasts | Absent (photosynthetic lamellae in cyanobacteria) | Present algaeinplants |
| Cell wall | Peptidoglycan (murein) | Cellulose (plants), Chitin (fungi), Absent (animals) |
| Cytoskeleton | Absent (primitive MreB actin-like) | Present (microtubules, microfilaments, IF) |
| Cell division | Binary fission | Mitosis / Meiosis |
| Flagella | Flagellin protein, no 9+2, rotates | Tubulin, 9+2 arrangement, bends |
| Examples | Bacteria, Cyanobacteria | Plants, Animals, Fungi, Protists |