Chapter 28.1 Flashcards
What type of body cavity do mollusks have?
Coelomates
What kind of body plan do mollusks have?
3-part
What kind of symmetry do mollusks have?
Bilateral
What outer covering do most mollusks have?
Shell
What are the three parts that make up the basic mollusk body plan?
Visceral mass, mantle, foot
What is the visceral mass?
The central section of the mollusk’s body that contains its organs
What is the mantle?
A heavy fold of tissue that forms the outer layer of the body and secretes the mollusk’s shell
What is the foot used for?
Locomotion
What is the radula and what type of mollusks lack it?
A tongue-like organ covered with thousands of pointed curving teeth used for feeding-bivalves
What phylum are mollusks in?
Mollusca
What does the coelom of mollusks contain?
Body fluids that are full of waste
What do nephridia do?
Recover useful materials such as sugars and salts
Where does the waste fluid of a mollusk exit?
Through a pore that opens into the mantle cavity
How many chambers do mollusks have in their hearts?
3
What type of circulatory system do mollusks have?
Open except for octupuses
What is the name for the “blood” of mollusks?
Nemolymph
How do mollusks respire?
With gills located in the mantle cavity
How are mollusks gendered?
Separate male and female
Where does the fertilization of eggs occur?
Externally in aquatic mollusks, internally in terrestrial mollusks and in octopuses
What do the fertilized eggs of aquatic mollusks develop into and how does it move?
Trochophore, belt of cilia
What are the three major classes of mollusks?
Gastropoda-snails and slugs
Bivalvia-clams, oysters and scallops
Cephalopoda-octopuses and squids
What are the three characteristics of gastropods?
Single shell, pair of tentacles, eyes on tips of tentacles
How do gastropods move?
With their foot on mucus
How do gastropods get food?
Herbivores/active predators
