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.

In this regard, are molluscs bilaterally symmetrical?

Mollusks are generally considered a phylum of bilaterally symmetrical animals, although there are also many asymmetrical species.

Beside above, are mollusks symmetrical or asymmetrical? All gastropods are asymmetrical. This is easily seen in snails and sea snails, which have helical shells. At first glance slugs appear externally symmetrical, but their pneumostome (breathing hole) is always on the right side. The origin of asymmetry in gastropods is a subject of scientific debate.

Hereof, are mollusks bilateral or radial?

Mollusks have bilateral symmetry, meaning a line divided down the middle of their bodies delineates their symmetrical halves.

What symmetry do mollusks have?

Mollusks PP. 324-326

A	B
What type of symmetry do mollusks have?	Bilateral Symmmetry
What type of cavity do mollusks have?	fluid filled body cavity
In the case of a mollusk:______ is a layer of tissue that produces shell	mantle
these exchange co2 and o2 for the mollusk	gills

Related Question Answers

Does porifera have symmetry?

Asymmetry. Only members of the phylum Porifera (sponges) have no body plan symmetry.

Do mollusks have a complete 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. Food is distributed to the cells of the body by blood.

What are the 3 body regions all mollusks have?

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.

Is Pila asymmetrical?

Snail, pila, octopus, mussel belongs to phylum Mollusca. Among them, only pila is asymmetric rest all shows bilateral symmetry.

Do mollusks have a true Coelom?

Both molluscs and annelids probably evolved from free-living flatworms. But molluscs have developed a true coelom, an internal body cavity enclosed by mesodermal membranes. The coelom in molluscs, however, is strangely reduced to a small space around the heart, sometimes called a hemocoel.

What type of symmetry do humans possess?

bilateral symmetry

Are echinoderms radial or bilateral?

The echinoderms have a radially arranged, pentamerous body structure that is very different from the bilateral body structure of the related deuterostome phyla, the hemichordates and the chordates. Yet, all three phyla evolved from a common bilaterally symmetric ancestor (Eernisse & Peterson 2004; Smith et al.

Are cnidarians radial or bilateral?

Cnidarians are generally believed to be radially symmetrical animals, but some cnidarians, such as the sea anemone Nematostella, display bilateral symmetry with an oral-aboral axis and a directive axis, which is orthogonal to the oral-aboral axis.

How do bivalves eat without a head?

Bivalves don't have a head. They feed by filtering out food from the water in which they live. They actually eat with the same structure used for breathing: the gills. Tiny particles of food get caught in the gills and cilia near the gills move the particles into the mouth.

Do gastropods have bilateral symmetry?

Externally, gastropods appear to be bilaterally symmetrical. However, they are one of the most successful clades of asymmetric organisms known.

Are mollusks vertebrates?

Mollusks are invertebrates that have a mantle -- a body structure that excretes a shell or protective coating for the animal.

Do flatworms have radial symmetry?

Unlike, the animals in the Phylum Cnidaria which have radial symmetry, those in the Phylum Platyhelminthes have bilateral symmetry. This means there is only one plane of symmetry (one way you can slice the animal in half and produce two pieces that are mirror images of one another).

Are arthropods radial or bilateral?

One character inherited by all arthropods is bilateral symmetry.

Are all bivalves bilaterally symmetrical?

Bivalves typically display bilateral symmetry both in shell and anatomy, but there are significant departures from this theme in taxa such as scallops and oysters. Bivalves lack a head, radula, and jaws.

Do scallops have bilateral symmetry?

Scallops are common marine bivalves in much of the fossil record and in the modern oceans. Individual bivalve shells, unlike brachiopod shells, are asymmetrical. Scallop shells sometimes approach bilateral symmetry, but the subtriangular, wing-like auricles along the hingeline will still display asymmetry.

What are the 4 classes of Mollusca?

The Phylum Mollusca consist of 8 classes: 1) the Monoplacophora discovered in 1977; 2) the worm-like Aplacophora or solenogasters of the deep sea; 3) the also worm-like Caudofoveata; 4) the Polyplacophora, or chitons; 5) the Pelecypoda or bivalves; 6) the Gastropoda or snails; 7) the Scaphopoda, or tusk shells; and 8)

What color is a gastropods blood?

As in other molluscs, the circulatory system of gastropods is open, with the fluid, or haemolymph, flowing through sinuses and bathing the tissues directly. The haemolymph typically contains haemocyanin, and is blue in colour.

What is the only group of terrestrial mollusks?

All terrestrial molluscs belong to the class Gastropoda.

Are mollusks considered animals?

Mollusca is one of the most diverse groups of animals on the planet, with at least 50,000 living species (and more likely around 200,000). It includes such familiar organisms as snails, octopuses, squid, clams, scallops, oysters, and chitons.

What are mollusks with two shells called?

Bivalve mollusks (e.g., clams, oysters, mussels, scallops) have an external covering that is a two-part hinged shell that contains a soft-bodied invertebrate.

What are the three basic types 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.

Are mollusks soft?

Mollusks are soft-bodied invertebrates of the phylum Mollusca, usually wholly or partly enclosed in a calcium carbonate shell secreted by a soft mantle covering the body.

Do mollusks have a mantle?

The mantle of mollusks and brachiopods secretes the shell in species that possess shells. It also forms a mantle cavity between itself and the body. The brachiopod mantle has a dorsal and a ventral lobe covered with small papillae (nipple-like projections) that penetrate into the shell.

What is the most intelligent group of mollusk?

cephalopod

Do mollusks have a nervous system?

In the nervous system typical of mollusks, a pair of cerebral ganglia (masses of nerve cell bodies) innervate the head, mouth, and associated sense organs. Other mollusks have various grades of ganglia, all of which may be concentrated anteriorly.

How does the first cockle avoid the moon snail?

It can get itself free because they can twist away because of the muscle power of their foot and it's connected to their shell. How does the first cockle avoid the moon snail? It can kick predators away. It burroughs down to get a cockle that is already buried.

Is an octopus bilateral symmetry?

Octopuses have bilateral symmetry in their body, meaning the left side is a mirror image of the right side. Animals with bilateral symmetry always have a preferred direction of locomotion relative to the orientation of the body. Because octopus arms are extremely flexible, they can move in many ways.