What has led scientists to believe that echinoderms are more closely related to humans and other vertebrates than to cnidarians?

List two modern organisms that have pentameral symmetry

Aboy jumps into a cold swimming pool and his body tempature goes down hus muscles ,blood vessels

How are gross production and net production different? a. net production is always greater than gross production. b. net production is always less than gross production. only animals have net production. d. only plants have net production. select the best answer from the choices provided