Mutualistic relationships between microbes and insects are common because insects . Multiple choice question. lack a digestive tract, and therefore rely on endosymbionts for carbon require additional energy to support high levels of activity lack any immune defenses, and therefore rely on microbes for this function often consume diets lacking essential nutrients

African penguins, which inhabit the coasts of southern africa, were classified as an endangered species in 2010. two significant threats to their survival are ecosystem damage from oil spills and overfishing by humans. overfishing depletes the food supply of african penguins. the best method to reduce the threat of overfishing would be to . the risk of oil spills could be reduced by increasing the use of , which should oil consumption. if an oil spill does occur, could be used to remove the oil so the ecosystem may more quickly recover.