Both Chlamydomonas and Spirogyra are photosynthetic green algae adapted for water-rich environments. Their main plant body is haploid (n) and gametophytic.
Similarities
| Chlamydomonas | Spirogyra |
| The simplest green plants adapted for water life. | The simplest green plants adapted for water life. |
| Their main plant body is a haploid (n) gametophyte. | Their main plant body is a haploid (n) gametophyte. |
| Meiosis occurs before the germination of the zygote. | Meiosis occurs before the germination of the zygote. |
Differences
| Chlamydomonas | Spirogyra |
| The plant body is unicellular. | The plant body is multicellular and filamentous in which, several cells are placed end to end. |
| Their cells may be oval, pear-shaped, and may be oblong. | Their cells are cylindrical. They are generally three to four times longer than breadth. |
| Their cell wall is non-slimy and is not of pectic material. | Their outer cell wall is slimy and is composed of pectic material. |
| It has two flagella. | It has no flagella. |
| They have a pair of contractile vacuoles. | They have a large vacuole. |
| There is only one pyrenoid body in the chloroplast. | There are numerous pyrenoids. |
| They have a cup-shaped chloroplast. | They have spirally coiled chloroplast. |
| They have an eye spot. | They don’t have eye spots. |
