U10D2 Mollusks

They have a backbone

They live only in shallow water

They lack a vertebral column

They are all microscopic

Digestive system

Nervous system

Circulatory system

Respiratory system

Scraping food from surfaces

Tearing apart prey

Creating an external shell

Grazing on algae and plants

They have a radula for feeding.

They have two hinged shells.

They reproduce through external fertilization.

They use a muscular foot to burrow.

Highly developed nervous systems

External shell for protection

Possession of chromatophores

Active predators with excellent vision

Aragonite

Conchiolin

Calcium carbonate

Silica

Porifera have well-developed organ systems, while mollusks do not.

Mollusks are asymmetrical, while Porifera are bilaterally symmetric.

Porifera lack true organs, while mollusks have well-developed organ systems.

Both Porifera and mollusks have calcium carbonate shells.