The Phylum shares features with other animal phyla. The mollusks are bilaterally symmetrical, have an organ system level of body organization, have a complete digestive system, and a coelom (small in size). Additionally these animals have a circulatory system and a respiratory system.
What systems do plants have? shoot system.


What are the six body systems found in molluscs?

The basic mollusk body plan showing the relative positions of the head, foot, and shell. The following organ systems are also shown: circulatory and respiratory systems, digestive system, nervous system, excretory system, and reproductive system.

Do mollusks have a skeletal system?

Unlike the internal skeleton of humans, mollusks actually have an external skeleton. This exoskeleton protects the animal’s soft inner body parts and acts as a sight for muscle attachment.

Do mollusks have a brain or nervous system?

Molluscs, with the exception of the most highly developed cephalopods, have no brain in the strict sense of the word. Instead, the cell bodies (pericarya) of nerve cells are concentrated in nerve knots (ganglia) in important parts of the body. … In gastropods, the ganglia originally have been dispersed over the body.

Do mollusks have a closed system?

Most mollusks have an open circulatory system but cephalopods (squids, octopus) have a closed circulatory system. The blood pigment of mollusks is hemocyanin, not hemoglobin. The heart of a clam can be seen in the photograph below.

Which characteristic do all mollusks have?

Mollusks have a soft body and share several characteristics, including a muscular foot, a visceral mass of internal organs, and a mantle.

What type of body symmetry Do mollusks have?

Mollusks have bilateral symmetry. – The two halves of the body mirror each other. Gastropods (snails) ~ eat with a radula (tiny tongue covered with teeth.

Does Mollusca have muscular system?

Mollusks have a muscular foot, which is used for locomotion and anchorage, and varies in shape and function, depending on the type of mollusk under study.

Do mollusks have an endo or exoskeleton?

Mollusks have neither endoskeletons nor exoskeletons. While they are protected by a shell that attaches to their body, their shells differ from…

What type of circulatory system is found in most mollusks?

Mollusks possess an open circulatory system in which body fluid (hemolymph) is transported largely within sinuses devoid of distinct epithelial walls.

Do mollusks have a digestive system?

Clams (and all mollusks) have a complete digestive system. It consists of a mouth where food is ingested, a short connecting tube called the esophogus, a stomach which temporarily holds food, and an intestine where food digestion and absorption takes place.

What kind of nervous system does an echinoderm have?

The adult echinoderm nervous system is composed of a central nervous system made up of a nerve ring connected to a series of radial nerve cords.

Do mollusks have tissues?

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 type of excretory system do mollusks have?

Molluscs also have a well-developed excretory system, using tubular nephridia organized as kidneys, that collect liquid wastes from the coelom and dump them in the mantle cavity, where they are pumped out of the shell. Sexes are separate (dioecious), except for bivalves and some snails, which are hermaphroditic.

Do mollusks have bilateral symmetry?

Mollusca can be found in freshwater, marine and terrestrial habitats. More features of molluscs include bilateral symmetry, soft or unsegmented bodies, respiration via ctenidium, ganglia/nerve comprised nervous system, haemocoel body cavity, etc.

Why do mollusks have an open circulatory system?

Mollusks have an open circulatory system, meaning the blood does not circulate entirely within vessels but is collected from the gills, pumped through the heart, and released directly into spaces in the tissues from which it returns to the gills and then to the heart.

What body characteristics do mollusks have in common quizlet?

Mollusks all have a mantle, a shell secreted by the mantle, a visceral hump, a foot, and a radula. Mollusks are different from other phyla because they have these things, most of which are unique to the phylum Mollusca. Describe the valve of a clam. The valve of a clam is also known as each half of the clam’s shell.

What is the main characteristic that all molluscs have in common?

Main characteristics of Mollusca : Unsegmented soft body with bilateral symmetry. Presence of an internal or external shell. A toothed tongue (made mostly of chitin) called the radula. A mantle which is a fold in the body wall that lines the shell.

What are 3 traits that all mollusks have?

Some of these characteristics are the presence of a shell, the type of shell, the type of foot, the arrangement of teeth in the radula, and the complexity of the nervous system. The three major groups of mollusks are gastropods, bivalves, and cephalopods (SEF ul o pods).

Do mollusks have bilateral or radial symmetry?

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.

Do any mollusks have radial symmetry?

Mollusks have radial symmetry. Mollusks have joined appendages. Mollusks have a muscular foot. … Arthropods have radial symmetry.

Do all mollusks have a soft body and bilateral symmetry?

What type of symmetry do Mollusks have? They have bilateral symmetry. … Animals that belong to the Mollusks. Mussels, clams, snails, octopus, and squid.

Do mollusks have arms?

Mollusks in which typical molluscan foot surrounds head and forms arms and tentacles; mantle surrounds mantle cavity and is part of locomotory system; central nervous system highly developed, forming true brain encased in cartilaginous cranium; mouth contains pair of parrotlike jaws (or beak); body usually somewhat …

Does a Mollusca have a shell?

mollusk, also spelled mollusc, any soft-bodied invertebrate of the phylum Mollusca, usually wholly or partly enclosed in a calcium carbonate shell secreted by a soft mantle covering the body.

What is the major component of the exoskeleton of mollusks?

The shell consists mainly of calcium carbonate and proteins called conchiolins, which are secreted by the epithelial cells on a tissue of the mollusk called the mantle.

Do mollusks have chitin?

Chitin is contained in larval mollusc shells which have to accommodate significant variations in terms of shape and composition of the interfacial tissue and “shell gland,” before it differentiates into the so-called mantle epithelium later in development (Kniprath 1981; Weiss et al.

Do Mollusca have appendages?

ArthropodaMolluscaMost of the arthropods have closed circulatory systems.Molluscs have open circulatory systems.

What type of mollusk has a closed circulatory system quizlet?

Cephalopods have a closed circulatory system where as other mollusks have an open circulatory system.

Do molluscs have a closed circulatory system?

Arthropods, such as this bee and most mollusks, have open circulatory systems. In contrast to a closed system, arthropods (including insects, crustaceans, and most mollusks) have an open circulatory system.

What are two characteristics that mollusks and annelids share?

Annelids have other similarities with mollusks, including: A closed circulatory system (like cephalopods). An excretory system consisting of tubular nephridia. A complete digestive system.

Which part of the mollusk body contains organs?

The mollusk body can generally be divided into three regions: the head, the foot, and a cluster of internal organs called the visceral mass. The visceral mass includes many of the organs mentioned in the previous concepts such as the stomach, the heart, the nephridia, and the gonads.

Do molluscs have intracellular digestion?

Digestive enzymes are secreted into the lumen of these glands. Additional extracellular digestion takes place in the stomach. In cephalopods, digestion is entirely extracellular. In the most other mollusks, the terminal stages of digestion are completed intracellularly, within the tissue of the digestive glands.

What type of skeleton does an echinoderm have?

The Phylum Echinodermata doesn’t always have spiny skin, or a spiny surface, but these animals do all share a calcium carbonate internal skeleton, or endoskeleton.

What is cnidarians nervous system?

The basic plan of the cnidarian nervous system is that of a nerve net which, at some locations, has condensed to form nerve plexuses, or circular or longitudinal nerve tracts which may be syncytia. … All these data indicate that evolutionarily “old” nervous systems use peptides as transmitters.

What is arthropod nervous system?

The arthropod nervous system consists of a dorsal brain and a ventral, ganglionated longitudinal nerve cord (primitively paired) from which lateral nerves extend in each segment. The system is similar to that of annelid worms, from which arthropods may have evolved. … The stomatogastric system regulates digestion.

What structures do all mollusks have in common?

WHAT FEATURES DO MOLLUSKS HAVE IN COMMON? As well as a shell, most mollusks have a muscular foot for creeping or burrowing. Some also have a head with sense organs. The soft body includes lungs or gills for breathing, and digestive and reproductive parts, all enclosed by a skinlike organ called the mantle.

Do mollusks have jointed appendages?

Arthro – means Jointed… Poda means Appendages. Therefore it is clear that Arthropods have jointed appendages whereas Molluscs do not have jointed appendages. Arthropods have a Chitinous exoskeleton while Molluscs have a calcareous exoskeleton (if present).