<span>The answer to your question is:
</span>
<span>
I hope that this is the answer that you were looking for and it has helped you.
</span>
The answer is single opening. The gastrovascular cavity varies from the alimentary canal in that only the gastrovascular cavity has only a single opening. In addition, an alimentary canal has two openings and food moves over it unidirectional. The gastrovascular cavity is a construction establish in primitive animal phyla. It is accountable in cooperation with the digestion of food and the transportation of nutrients all over the body.
Hi!
Rock pools are exactly what they sound like. They are rocky pools by the sea. They are usually found in the intertidal zone. During the occurrence of a high tide, they are filled with seawater. During low tide, they usually become/exist as separate pools.
Hope this helps, have a wonderful day/night!
