Question

19 a pond food chain is shown. which organism is a producer? a. tadpole c. sun b. heron d. hornwort

Explanation:

In a food chain, producers are organisms that can make their own food through photosynthesis. Hornwort is a plant (algae - like in some cases but generally a plant in such simple food chain setups) that uses sunlight (from the sun, which is an energy source not an organism in the biological producer - consumer sense) to produce food. Tadpole and Perch are consumers (tadpole is a primary consumer, perch is a secondary consumer in this chain), Heron is a tertiary consumer.

Answer:

d. Hornwort