Can an organism ever be both primary consumer and a tertiary consumer?

Yes, an organism can be both a primary consumer and a tertiary consumer, depending on its diet and ecological context. For instance, some species can feed on plants (acting as primary consumers) when resources are available and shift to eating other animals (acting as tertiary consumers) when circumstances change, such as during food scarcity. This flexible dietary strategy is often seen in omnivorous species, which can adapt to varying food sources within their ecosystem.