Biology is the study of life, and uses the scientific method, the basis of science, to do so. Hypotheses are made, tested, and remade, until a theory is made, which then becomes Scientific law.
Starfish has a endoskeleton
a coral has a exoskeleton
sponge has neither
Science is based on the feature of "<span>detailed research with reliable sources" among many other things. It is crucial that the tests can be repeated with the same results. </span>
They have 46, instead of the usual 47.
