Where can I find a peer reviewed article on the plants role in the food chain?
A good place to start is the Academic Search Complete Database. You can do a search for PLANTS in the first search box and "FOOD CHAIN" in the second box. Be sure to include the " ". You can limit your search to the last ten years if you like. I think I recall that this is part of your assignment. You can also limit to full text if you like. I have included a link to a search done in this way. You can look through these results to find articles of interest to you. You should find peer reviewed as well as popular science ones. If you like you can limit to peer reviewed to make that part easier.