Final answer:
An ecosystem consisting only of frogs and mosquitoes would not be sustainable due to a lack of food, habitat diversity, and ecological resilience.
Step-by-step explanation:
An ecosystem that consists only of frogs and mosquitoes would not be sustainable for several reasons. First, frogs are an important part of many food webs and help control insect populations, including mosquitoes. However, if there are no other organisms in the ecosystem, the frog population would quickly outstrip the mosquito population, leading to a shortage of food for the frogs. Second, frogs rely on a diverse range of habitats, including water bodies and land, for breeding, feeding, and shelter. Without other organisms and ecological interactions, the ecosystem would lack the necessary variety of habitats to support the frogs' needs. Lastly, a lack of biodiversity can make an ecosystem more vulnerable to disturbances and less resilient to environmental changes. In such a limited ecosystem, a single event or change could have catastrophic effects on both the frog and mosquito populations.