| Characteristic | Euchromatin | Heterochromatin |
| Chromatin condensation | Less condensed | More condensed |
| Location | On chromosome arms | At centromeres, telomeres, and other specific places |
| Type of sequences | Unique sequences | Repeated sequences* |
| Presence of genes | Many genes | Few genes* |
| When replicated | Throughout S phase | Late S phase |
| Transcription | Often | Infrequent |
| Crossing over | Common | Uncommon |