What are the 3 main parts of a mollusks body plan?

What are the 3 main parts of a mollusks body plan?

Despite their diversity, mollusks share in common a three-part body plan that includes a head, a foot and a visceral mass.

What is the body structure of mollusks?

The basic body structure, consisting of a foot, visceral mass, and mantle, is similar in most mollusks. The foot is located below the visceral mass. The external shell consists of three layers. The thin outer layer, called the periostracum, is made of a tough hornlike material and serves to protect the lower layers.

What are the four parts of the mollusk body plan?

The four important body parts in the mollusk could be listed as: Shell, Mantle, Visceral Mass and Foot.

What are the basic characteristics of molluscs?

Characteristic Features of Phylum Mollusca

• They are bilaterally symmetrical.
• They are triploblastic, which three layers.
• They show organ system grade of organisation.
• The body is soft and unsegmented.
• Body is divisible into three regions – head, a visceral mass, and ventral foot.
• Body is covered by a mantle and shell.

What are the two main parts in all mollusks?

What are the two main parts in all mollusks? Most mollusk have two organs that are unique to this phylum: a specialized feeding organ called a radula and a dorsal layer of tissue called a mantle. Mollusks are the first animals to have evolved organ systems for respiration and circulation.

How do mollusks move?

Most mollusks move with a muscular structure called a foot. These are mollusks like snails and slugs that have just one shell or no shell at all. Gastropods creep along on their broad foot. The word “gastropod” means “stomach foot” because most of them have their foot on the same side of their body as their stomach.

What are the three major classes of mollusks?

The three major groups of mollusks are gastropods, bivalves, and cephalopods (SEF ul o pods). The largest group is the gastropods. These are mollusks like snails and slugs that have just one shell or no shell at all. Gastropods creep along on their broad foot.

How are mollusks classified?

Mollusks can be segregated into seven classes: Aplacophora, Monoplacophora, Polyplacophora, Bivalvia, Gastropoda, Cephalopoda, and Scaphopoda. These classes are distinguished by, among other criteria, the presence and types of shells they possess.

What are the four major classes of mollusks?

The four major groups of mollusks (phyla Mollusca) are: 1) chitons; 2) gastropods, including snails, slugs (mostly marine, but some freshwater), and nudibranches.

What do all molluscs have in common?

Mollusks have a hard outer shell. There is a layer of tissue called the mantle between the shell and the body. Most mollusks have tentacles for feeding and sensing, and many have a muscular foot. Mollusks also have a coelom, a complete digestive system, and specialized organs for excretion.

What kind of body plan does a mollusk have?

Despite their diversity, mollusks share in common a three-part body plan that includes a head, a foot and a visceral mass. The Head. The mollusk’s head region contains the brain. The Foot. A mollusk has a “foot,” the body’s muscular section, responsible for movement.

Where are the body organs of a mollusk located?

Mollusks have a thin layer of tissue called the mantle. The mantle covers the body organs, which are located in the visceral mass. Between the soft body and the mantle is a space called the mantle cavity.

What does the mantle do in a mollusk?

Each body part has its own specific function. Mantle (and mantle cavity): Mollusks have a thin layer of visceral tissue called the mantle, which covers the body organs. It contains a gland that helps in the formation of hard shell. Mantle cavity is the space between the soft body and the mantle.

What kind of tissue does a mollusc have?

All molluscs posses a mantle, which is a layer of tissue that covers the organs (1). This mantle protects the organs, and, in case the organism doesn’t have a shell, this tissue is the only protection the organism will get.