The food chain in a visual representation of how energy is flowed through out a specific environment. While it is very similar to the food web, the main difference is that the web gives a more broad wide range of organisms and it is more specific with what eats what. The second part of your question about a few animals roles umm... Grass is a producer which has the role of feeding primary consumers, it is the base of the chain or web without it the whole thing would collapse. Tertiary consumers such as owls have the role of eating secondary consumers. I always thought of it like the tertiary consumers are population control since nothing eats them they have no responsibility to feed other organisms just make sure that secondary consumers don't overpopulate.
Eukarya is the domain containing all organisms with eukaryotic cells.
The answer is A.True but they are not the only ways in which this can occur.
The statement that best describes the work of these researchers is "As a result, the researchers have been able to achieve protein-folding simulations that are far better than those other computing methods have done." I hope my answer has come to your help. God bless and have a nice day ahead!