Question 1: Basically, producers are things like plants the are the first source of food. Primary consumers are the first to eat the producers (like small fish, insects, etc) Secondary consumers (foxes, larger fish, etc) consume the primary consumers, and tertiary consumers (sharks, humans, whales, etc.) consume the secondary consumers. Decomposers (fungi, bacteria, etc) like the name suggests decompose rests of food and organisms and send the nutrients back into the earth.
Questions 2&3: An autotroph is an organism that produces its own food (like plants do through photosynthesis) and a heterotroph is an organism that cannot produce its own food and has to seek out other sources of food.
Question 4: Grass, Dragonfly, Trout, human
Question 5: Bean plant, rabbit, fox, bacteria
Questions 6&7: They are a little harder to explain in text form but hopefully my explanations can help you figure out the answer yourself.
