This document outlines the main types of interactions that can occur between organisms in an ecosystem. It discusses biotic interactions like predation, grazing and competition. It also discusses symbiotic relationships between species including parasitism, commensalism and mutualism. Finally, it notes that interactions between species and with the environment can have various costs, benefits and consequences.

1. (b) INTERACTIONS IN ECOSYSTEMS 1. Biotic Interactions (Predation, Grazing, Competition) 2. Symbiotic Relationships (Parasitism, Commensalism, Mutualism) 3. Costs,Benefits & Consequences of these interactions (Interactions between species, Interactions with the environment)