Gdz — Biologiia 7 Sumatokhin Klass Dvukhstvorchatye Molliuski

Mouth (near the foot), stomach, liver, and intestine. They lack a radula (grating tongue). Plate-like gills (ctenidia) located in the mantle cavity. Excretory Two kidneys that open into the mantle cavity. Nervous Simplified, consisting of three pairs of ganglia. Ecological and Economic Importance

: They are filter feeders . Water enters through an inhalant siphon, passes over the gills where food particles are trapped, and exits through an exhalant siphon. gdz biologiia 7 sumatokhin klass dvukhstvorchatye molliuski

: Like most mollusks, they have an open circulatory system where the heart pumps blood into the body cavity. Internal Anatomy Summary Characteristic Digestive Mouth (near the foot), stomach, liver, and intestine

(class Bivalvia ) are a unique group of aquatic mollusks characterized by a shell consisting of two hinged valves and, most notably, the absence of a head . In the Grade 7 Biology curriculum by Sumatohin, they are studied as essential bio-filters and members of aquatic ecosystems. Key Biological Features Excretory Two kidneys that open into the mantle cavity