What phylum is characterized by the presence of a mantle. Also know as mollusks, there are over 85,000 known species of mollusca that range in all kinds of marine, fresh water and terrestrial habitats. The number of fossil species is estimated between 60,000 and 100,000 additional species. The molluscs mollis soft are softbodied animals with a hard external or internal shell. Reproduction and circulatory system phylum mollusca. Their system contains this hard skeleton shell that protects the soft body inside. Mollusks better known as snails,clams, and other relatives all mollusks have soft bodies their name is derived from the latin word mollus meaning soft.
Nielsen 2001 identifies 5 synapomorphies that define the phylum. Name three ways in which insects are beneficial to humans pollinate, decompose, and feed 9. The phylum chordata chordata the circulatory system. Mollusca questions and study guide quizlet flashcards by. Download objective type questions of phylum mollusca pdf visit our pdf store. These classes are defined primarily on the basis of body plan, type of shell, and modifications of the internal organs. The phylum mollusca is the second largest group of invertebrates. What body segment are the wings and legs attached to. Ejection fraction, quantitative, nci thesaurus a natural protein isolated from the marine mollusc keyhole limpet. Phylum mollusca includes invertebrates that are found in freshwater and saltwater environments as well as terrestrial areas that are moist. The characteristics of chordates include bilateral symmetry, a segmented body, a ventral heart. Mollusks are members of the phylum mollusca, and you can use this interactive quiz and worksheet to selfassess your knowledge of this branch of animals.
The phylum mollusca is a very large phylum consisting of invertebrate animals. A closed system means that the flow of blood is through blood vessels. The protostome is when the blastopore becomes the mouth. Cephaloda, scaphopoda, bivalvia, alpacophora, polypacophora, monoplacophora, and gastropoda. All insects have 2 pair of wings and 3 pair of legs. Human papillomavirusrelated esophageal squamous cell carcinoma, nci thesaurus. The mollusks are among the most diverse, and wellknown of the invertebrate groups and include the clams, snails, tusk shells, chitons, and squids. Two gonads sit next to the coelom, a small cavity that surrounds the heart and shed ova or sperm into the coelom. Body is soft elongated, cylindrical or flattened divided into. Mollusks are a very diverse phylum, were species like the snail and squid are grouped together. Phylum mollusca the shape of life the story of the. Woo, 2010 preliminary checklist of the molluscs of singapore pdf, raffles museum of biodiversity research, national university of singapore. A mantle is a fold of skin whos job in some organisms it is to produce the shell by secreting. Phylum mollusca class cephalopoda order sepioidea family sepiidae genus sepia species sepia officinalis.
This video explains the characteristics and classes of the phylum mollusca. The early molluscs that happened to develop hard shells. Mollusca the softbodied animalsthe softbodied animals 3. They are the largest marine phylum, making up 23% of all marine life, however there are also terrestrial mollusks as well. The species in this phylum live in diverse environments which can range from arctic seas to tropical streams to high mountainsides. They have gills in order to get oxygen from the water. Home interesting facts contact reproduction and circulatory system body plan and symmetry shells jokes for the folks reproduction and circulatory all produce eggs, from which may emerge larvae, or miniature adults. A snail has an open circulatory system which means that blood is not restricted from traveling within the blood vessels. The phylum mollusca is made up of the invertebrate organisms that we call mollusks. The phylum is extremely diverse and examples of these organisms could range from squids to snails. Free living found in moist soil, fresh water, sea or few are parasite. It also has the muscular foot region that is used for movement.
They depend on maintaining a constant water flow through their bodies to obtain food and oxygen and to remove wastes, and the shapes of their bodies are adapted to. They infect molluscs, mammals, and birds and some are transmitted by arthropod vectors. English for beginners practical english travel english telephone english banking english accounting english dictionary. Doubleclick any word on the page to look it up in the dictionary. Notes on mollusca snail zoology biology discussion. They can be found in terrestrial regions as well as in the depths of the seas. The phylum mollusca is an extremely vast group of animals with a resultantly vast array of physical attributes, although some features are shared by all creatures who are a part of it. Eukaryathis domain is characterized by cells that have a double bounded nucleus, cytoplasm, and a plasma membrane campbell 2008. Mollusca is the second largest phylum in terms of species. Phylum mollusca from the shape of life on the pbs website. The mollusks compose the large phylum of invertebrate animals known as the phylum mollusca.
Information about phylum mollusca in the dictionary, synonyms and antonyms. The phylum includes mammals, birds, reptiles, and amphibians. Over 50,000 of these species belong to the mostly marine and freshwater caenogastropoda while another 20,000 species belong to the subclass pulmonata, of which most are terrestrial. The phylum chordata is made up of the most evolved animals. Animals in phylum mollusca have an open circulatory system, but also often have a heart that pumps blood. To know more about mollusca, keep visiting byjus website or download byjus app for further reference. The phylum mollusca is one of the larger invertebrate animal phyla, and its members can be found on land, as well as in both freshwater and saltwater environments.
Phylum mollusca mcq multiple choice question and answer phylum mollusca mcq with detailed explanation for interview, entrance and competitive exams. The phylum contains all animals that, at some point in their lifetime had a stiffening rod, called a notochord. The phylum mollusca mollusca the circulatory system. They are found largely in water, but some are terrestrial too. How many insects species are estimated to be on planet earth. Gastropods are the most diverse class of the phylum mollusca, comprising almost three quarters of the 110,000 or so species of molluscs known. Some of the more popular classes are discussed here. The mollusca phylum is split into seven main categories called classes. The snail is one animal that makes up the mollusca phylum. Slugs and snails have a very similar circulatory system. Snails are classified in the phylum a chordata b mollusca. The heart of the snail is found on the left side of the body and is made up of one auricle and one ventricle. There are three distinct classes in this phylum, the gastropods, bivalves, and cephalopods. The animals in phylum mollusca all have bilateral symmetry.
The circulatory system in the phylum mollusca is at its simplest form. Mollusca has about 100,000 specieshas about 100,000 species bilateral symmetry and triploblasticbilateral symmetry and triploblastic mollusk bodies have three regionsmollusk bodies have three regions headfootheadfoot. The only animal within the porifera phylum that has does not have a circulatory system but carries out a form of circulation is a sponge. This phylum contains species where their bodies are covered by a hard exoskeleton such as shells of snails and clams or even the plates of chitons. Phylum mollusca objective type questions pdf download. Gastropods are sometimes referred to as univalves because they appear to have one half shells that cover their bodies. Mollusca the excretory systems of different phylum types. The octopus, sea slug, and squid are all part of the phylum mollusca. Mollusca is the secondlargest phylum of invertebrate animals after the arthropoda. The bodies are generally very soft and are covered by the hard exoskeleton. The phylum includes forms like chitons, snails, slugs, clams, oysters, sepia, loligo, octopus, etc. The most common terms for this group are limpets, snails, and slugs. The heart is key to keep the blood pressure regulated.
Malacology is the study of mollusca and conchology is the study of shell of mollusca. The class aplacophora comprises about 300 species of wormlike marine organisms that lack shells. Around 85,000 existing species are recognized to be a member of this phylum. Their coelom is reduced to small cavities around heart, lungs, and gonads. Phylum mollusca characteristics, classification and examples. The word mollusc comes from the latin meaning soft, a good description of the groups fleshy bodies. Mollusks are the largest marine phylum comprising 23% of all named marine organisms.
Numerous mollusks also live in freshwater and terrestrial on land habitats. They range from the slowmoving slug to the jetpropelled squid, from scallops and cuttlefish to chiton s and nudibranchs. Mollusks range in size from almost microscopic snails to giant squids, which can grow to be 21 m long. On the picture below you can see the nucleus is enclosed in a nuclear envelope. Cephalopoda these marine animals are characterized by bilateral body, a.
The phylum mollusca is divided into several classes. General characters of phylum mollusca the name mollusca in latin mollis soft, was first used by the french zoologist, cuvier in 1798 to describe squids and cuttlefish, animals whose shell is reduced and internal or entirely absent. Around 85,000 extant species of molluscs are recognized. Of course, in an ocean filled with predators, a soft body is easily eaten. Generally aquatic, some terrestrial and amphibious forms are also present. It was only later that the true affinities between squids and multiform and other molluscs such as snails. Phylum annelida, arthropoda, mollusca and echinodermata. Mollusca comprises some of the best known invertebrates like, snails, slugs, clams, squids and octopuses. Here is an overview of the phylum mollusca that includes the classification of mollusca, mollusca characteristics, and mollusca examples. Nervous system of phylum mollusca biology discussion. Another animinal within the mollusca phylum is a slug. Most of the circulatory systems in this phylum are open, but some are closed. The ventricle pumps blood through an aortic trunk to all parts of the body through a group of arteries and capillaries.
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