Antibiotics and allelopathic agents are secondary metabolites
A secondary metabolites is a substances produced by a pathway that only exists in same taxonomic group
--> aren't essential for cell growth or its function
Deters potential competitors from their ecological niches
Antibiotics:
Secreted by microorganisms to kill, inhibit or prevent the growth of other species of organisms
Produced by many fungi
E.g. penicillin
Allelopathic Agents:
Secreted into the soil by plants to kill or deter the growth of neighbouring plants.
E.g. sunflowers + walnuts