Final answer:
A food web with a Barn Owl at the uppermost trophic level can be constructed with plants as producers, a mouse as a primary consumer, a snake as a secondary consumer, and the Barn Owl as a tertiary consumer and apex consumer.
Step-by-step explanation:
A food web with a Barn Owl at the uppermost trophic level can be constructed as follows:
- Producer: Plants are the primary producers. They use photosynthesis to convert sunlight into energy.
- Primary Consumer: The primary consumers are herbivores that eat plants. For example, a mouse can be a primary consumer in this food web.
- Secondary Consumer: The secondary consumers are carnivores that eat the primary consumers. A snake can be a secondary consumer.
- Tertiary Consumer: The tertiary consumers are carnivores that eat other carnivores. In this case, the Barn Owl can be a tertiary consumer as it preys on snakes.
- Apex Consumer: The Barn Owl, being at the highest trophic level, is the apex consumer in this food web.
The food web diagram can be drawn with arrows pointing from the organism being consumed to the predator. The arrows should point from the plants to the mouse, from the mouse to the snake, and from the snake to the Barn Owl.