| 1. | Outer side of thylakoid membrane |
| 2. | Embedded in the thylakoid membrane |
| 3. | Lumen of thylakoid |
| 4. | Inner side of thylakoid membrane |
| 1. | Brought about by development of proton gradient. |
| 2. | Brought about by maintenance of proton gradient. |
| 3. | Brought about by breakdown of proton gradient. |
| 4. | Not dependent on proton gradient |
| 1. | Adaptability to dry tropical regions |
| 2. | Greater productivity of biomass |
| 3. | Presence of photorespiration |
| 4. | Response towards high light intensities. |