GENERAL HISTOLOGY

Detailed explanation-1: -Starfish and other echinoderms, such as sea urchins and sea cucumbers, are more closely related to humans than other more commonly studied invertebrates like insects and therefore provide a good model to study how molecules have evolved over hundreds of millions of years.

Detailed explanation-2: -Echinoderms are the most closely related phylum to the phylum Chordata, which includes many complex organisms such as humans. Their shared common ancestor was likely a bilaterally symmetrical organism with a cephalized (centralized in a head region) nervous system.

Detailed explanation-3: -Echinoderms are named for their spiny skin, which is covered by a thin layer of calcium carbonate plates and spines. Adult echinoderms have radial symmetry, but larvae have bilateral symmetry. Echinoderms have a unique water vascular system, with canals that extend along each body part.

Detailed explanation-4: -Which feature of echinoderms means that they are more closely related to humans than any other invertebrate group? They are deuterostomes.