What are the 4 main classes of mollusks?
- GASTROPODA (single shelled cowries, cones etc)
- BIVALVIA ( two shelled like clams, mussels etc)
- APLACOPHORA (solenogasters)
- MONOPLACOPHORA (segmented limpets)
- POLYPLACOPHORA ( or Amphineura as it was earlier called- Chitons)
- SCAPHOPODA (tusk shells)
- CEPHALOPODA (nautilus, squids, Cuttelfish, octopus etc)
What is the body structure of mollusks?
The body plan of a mollusk usually consists of a head region, a muscular foot, and a visceral mass of internal organs that is often contained within a dorsal shell. Each class possesses some variation on this basic plan.
What are the main characteristics shared by all mollusks?
The spiral is one of the oldest geometric shapes found in the ancient world – petroglyphs of the symbols date back to the Neolithic period, and they are one of the most common patterns in nature, found in the path of draining water or the eye of a hurricane.
What are the body parts of a mollusk?
The four parts of the mollusk body plan are the foot (used for locomotion), mantle (which secretes the shell), shell (which covers), and viceral mass (contains heart and organs). Describe the characteristics of the three major classes of mollusks.
What are the basic features of the mollusk body?
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 are the three characteristics of the mollusc body plan?
Characteristics of Mollusks Their bodies are made up of three main parts, including a muscular foot, a visceral mass, and a mantle.
Do molluscs have a distinct body plan?
Most important, molluscs have evolved a distinctive and highly successful body plan that features a mantle, shell, muscular foot, and radula. These features are evident in most contemporary molluscs, but have been highly modified in some groups.
What are the 3 main regions of the mollusk body?
In general, mollusks have 3 body regions: a head, a visceral mass, and a "foot." The head contains the sense organs and "brain," while the visceral mass contains the internal organs. The "foot" is the muscular lower part of the body which is in contact with the substrate.
What are the 4 parts of a mollusks body plan?
The body plan of most mollusks has four parts: foot, mantle, shell, and visceral mass.
What body parts do all mollusks have?
Despite their diversity, mollusks share in common a three-part body plan that includes a head, a foot and a visceral mass.
What type of body symmetry Do mollusks have?
Mollusks are generally considered a phylum of bilaterally symmetrical animals, although there are also many asymmetrical species. Bilateral symmetry means that an organism can only be divided into two equal halves if it is cut from top to bottom along the middle of the anterior-posterior (front-back) axis.
What is unique about Mollusca?
A feature unique to molluscs is a file-like rasping tool called a radula. This structure allows them to scrape algae and other food off rocks and even to drill through the shell of prey or catch fish.
What are the three body parts of a mollusk quizlet?
All molluscs are characterized by having three main body regions? Head-foot, which is the sensory and locomotor part of the body; a visceral mass, containing most of the organ systems; and a mantle, which covers the visceral mass and secretes the shell.
What are the 4 body regions characteristic of molluscs in order from outer to inner regions?
Mollusks are invertebrates with soft bodies covered with a shell of one or more pieces. The four parts of the mollusk body plan are the foot (used for locomotion), mantle (which secretes the shell), shell (which covers), and viceral mass (contains heart and organs).
What three components make up the body plan of mollusk quizlet?
All molluscs are characterized by having three main body regions? Head-foot, which is the sensory and locomotor part of the body; a visceral mass, containing most of the organ systems; and a mantle, which covers the visceral mass and secretes the shell.
What type of body symmetry do Mollusca have?
Mollusks are generally considered a phylum of bilaterally symmetrical animals, although there are also many asymmetrical species. Bilateral symmetry means that an organism can only be divided into two equal halves if it is cut from top to bottom along the middle of the anterior-posterior (front-back) axis.
Why do molluscs have soft bodies?
Mollusks have soft bodies, which makes them easy prey for many other kinds of animals. And so, mollusks have evolved many ingenious ways to protect themselves. On way that mollusks protect themselves is to build a hard shell around their bodies.
What are 3 ways that cephalopods differ from the other molluscan classes?
Cephalopods have a more developed nervous system than other mollusks. They also have very well developed eyesight that is used in finding prey. Once prey is found, it is grasped firmly and eaten with a mouth located at the base of the arms. Cephalopods also have a parrot-like beak which is used in biting into prey.
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Why is the inside layer of a mollusk the smoothest?
The inside layer is the smoothest but it is usually the thickest layer because it's added to throughout the life of the mollusk. The inside layer protects the soft body. Some Mollusks, such as the squid, have tentacles. The muscular foot, which is used for movement, is in the underside of the mollusk.
What type of symmetry do mollusks have?
The type of symmetry that mollusks have is bilateral symmetry. Meaning that the two sides are related. The picture shows muscular foot,visceral mass and the mantle. The mantle is a layer of tissue that covers the visceral mass and in many molluscs it contains glands which secrete a hard shell. Mollusks reproduce sexually.
What is the mantle of a mollusk?
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. Mollusks contain gills.
