Question

Which of the following best describes mollusks? a) They are bilaterally symmetrical and have a soft body sometimes covered with a shell. b) They are bilaterally symmetrical and have a soft body always covered with a shell. c) They have radial body symmetry and a soft body sometimes covered with a shell.

Answer 1

Answer:

They are bilaterally symmetrical and have a soft body sometimes covered with a shell.

Explanation:

Mollusks are bilaterally symmetrical organisms which means only two planes can divide their bodies into two identical halves. They are triploblastic organisms with organ system level of body organization. Mollusks have a soft body that is usually covered by a dorsal shell composed mainly of calcium carbonate. The foot is a broad, flat and muscular structure located ventrally. Foot serves these organisms in locomotion. The various body organs are present as visceral mass located above the foot. The visceral mass is covered by a thin sheet of tissue called mantle. Example: clams, snails, and squids.