BIO 1106 Study Guide - Quiz Guide: Anterior Segment Of Eyeball, Centipede, Book Lung
Document Summary
Phylum mollusca: one of first coelomate organisms, have coelomic body cavity surrounded by mesoderm and contain complex system of organs and compartments, part of protostomes. Are soft-bodied animals with epidermal cells called mantle: mantle secretes a shell. Have evolved a remarkable diversity of forms built on consistent ancestral body plan. Mollusks produce many kinds of external shells: some only have remnants of shell, others have no shell at all (squids?) Coelomate is often reduced to small chamber surrounding the heart. Open circulatory system: blood pools in sinuses and bathes organs directly, have a few large vessels and a heart but no smaller vessels and capillaries. Basic body plan: shows little segmentation, consistently includes. Visceral mass of organ systems: digestion, excretion, reproduction. Ventral, muscular, and often highly modified foot: foot used for locomotion. Mantle that secretes the shell and may aid in respiration and locomotion in some species: some also have differentiated head, generalized molluscan body plan.
