Class Gastropoda (Phylum Mollusca)

Question 1

They have torsion.

What is it and what are the advantages?

Answer 1

• 180 degree rotation of the visceral mass
• • head wired to go in first
• • able to form water tight seal w/ environment
• invasion of land is difficult b/c need fresh water → solution is torsion

Question 2

Digestive Tract

Answer 2

mouth (has radula) → esophagus → (with cilia) stomach → (w/ cilia) intestine → rectum → anus

Question 3

Reproduction

Answer 3

• monoecious – good adaptation for not being motile
• internal fertilization (typical for terrestrial)
• egg & sperm brought together in animal
• some are protandric