| Group 1 | Group 2 | ||
| (P) | Protocooperation | (i) | One species is harmed but the other is neither harmed nor benefitted |
| (Q) | Commensalism | (ii) | A type of mutualism where one species is benefitted more than the other |
| (R) | Amensalism | (iii) | Both the species are benefitted but the interaction between them is not obligatory |
| (S) | Helotism | (iv) | One species is benefitted without harming the other |

