Question

disadvantages of having one opening into the digestive cavity

Answer 1

Answer:

Organisms with a separate mouth and anus are sea star and frog. The disadvantage of a single opening over a complete digestive tract is that the organisms must wait for the waste food to be released before consuming new foods

Answer 2

The disadvantage of having single opening for ingestion as well as egestion is that organism having it has to wait untill the waste from the food already taken to excrete out. Only then it can intake more food.

Explanation:

This type of system can be easily seen in the lower most organisms like sponges or cnidarians as they have cellular level organisation and there is no system formed by combination of organs.