I am doing a project on echinoderm and one of the questions is asking about if they have a circulatory system. I have found information that they have a poorly defined opened circulatory system. I also need to answer the difference between if it's closed or open and this I don't understand? Could someone please help!!! thanks

Question

Gray · Answer

bioweb .wku .edu/courses/biol225/225lab9 .html

gsu .edu/~bioasx/closeopen .html

According to the first article, they don't have circulatory systems at all, and I assume that's because they do not have a heart.

Remove the spaces to access the webpages.

Anonymous · Answer

it is open listen to me everyone calls me anerd and dork that's mean but true and please listen to me and you will qet a good qrade