AP BIOLOGY

Detailed explanation-1: -Although molluscs are coelomates, their coeloms are reduced to fairly small spaces enclosing the heart and gonads. The main body cavity is a hemocoel through which blood and coelomic fluid circulate and which encloses most of the other internal organs. These hemocoelic spaces act as an efficient hydrostatic skeleton.

Detailed explanation-2: -In addition to the foot and hydrostatic skeleton, molluscs have other special traits that distinguish them from other animals. One is the mantle, a blanket of soft tissue that covers a mollusc’s body like a bathrobe.

Detailed explanation-3: -The coelom is a fluid-filled cavity that develops within the body. It functions as a hydrostatic skeleton and provides a space in which the internal organs can be suspended.

Detailed explanation-4: -Unlike the internal skeleton of humans, mollusks actually have an external skeleton. This exoskeleton protects the animal’s soft inner body parts and acts as a sight for muscle attachment.

Detailed explanation-5: -Hydrostatic skeletons are fluid-filled columns, or cavities, inside invertebrates, including jellyfish, flatworms, nematodes, and annelids such as earthworms.