Okay so I just took the test and it said the answer is <span>Something changed to limit and finally abolish their success in this environment! I hope this helps!</span>
Bone marrow contains stems cells which then turn into immature blood cells and they mature there. kinda like a school for young blood cells. they also make white blood cells and platelets.
B. Allows for specialized regions with specialized functions
Explanation:
Where the complete digestive system has different specialized regions to perform specialized functions, the gastrovascular cavity is the primary organ of digestion and circulation in two major animal phyla: the Cnidaria (including jellyfish and corals) and Platyhelminthes (flatworms).
Muscles connect to your<span> skeleton and they contract and </span>move the skeleton along.<span> The calcified bones of </span>your<span> skeleton also work with the circulatory </span>system<span>. </span>
