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. The majority of mollusks live in the ocean. Different classes of mollusks have different ways of obtaining food.
- 1 Which class of mollusks all have tentacles?
- 2 What does a mollusk not have?
- 3 What do all mollusks have in common?
- 4 Do bivalves have tentacles?
- 5 Do all mollusks have gills?
- 6 Why do some mollusks have shell?
- 7 What mollusks have no shells?
- 8 Do all molluscs have shells?
- 9 Are mollusks Autotrophs or Heterotrophs?
- 10 Do mollusks have a cuticle?
- 11 Which of the following types of a mollusk has only one shell?
- 12 Do mollusks have tissues?
- 13 Is Mollusca an exoskeleton?
- 14 What mollusk has eight arms and no shell?
- 15 Do mollusks have a mantle?
- 16 Why do mollusks not have shells?
- 17 Do all mollusks have a foot?
- 18 Do molluscs have jaws?
- 19 Do all mollusks have eyes?
- 20 What are two main parts in all mollusks?
- 21 What three structures do all mollusks have?
- 22 What type of shells do mollusks have?
- 23 Do all mollusks have bilateral symmetry?
- 24 What composes the shell of a mollusc?
- 25 Do mollusks have an endoskeleton or exoskeleton?
- 26 Can mollusks exhibit segmentation?
- 27 Do mollusks shed their shells?
- 28 Do mollusks change their shells?
- 29 Do mollusks have ventral nerve cords?
- 30 Do mollusks have a complete digestive system?
- 31 How are mollusks and annelids different?
- 32 Do molluscs have jointed limbs?
- 33 Do Mollusca have jointed appendages?
- 34 Are all exoskeleton shell structure?
- 35 Do mollusks have cartilage?
- 36 Do octopuses have arms or tentacles?
- 37 Which of the following is true of all mollusks except for cephalopods?
- 38 Do all octopi have 8 legs?
- 39 Where is the mantle located in most mollusks?
- 40 Which of the following groups are mollusks?
- 41 Which characteristic do all mollusks have quizlet?
- 42 How do you classify mollusks?
- 43 Why do mollusks have eyes?
- 44 Do mollusk eyes have a blind spot?
- 45 Which mollusk has the largest eye of all animals?
- 46 What characteristic is common to all mollusks?
- 47 What structures do all molluscs have in common?
- 48 How do Cephalopods differ from other molluscs?
- 49 Do all mollusks have shells?
- 50 How molluscs differ from other phylum describe?
- 51 Does a Polyplacophora have tentacles?
Which class of mollusks all have tentacles?
Class Cephalopoda. The cephalopods are molluscs with large heads and tentacles. Examples of cephalopod molluscs include squid, octopus, cuttlefish, and nautilus (Fig. 3.65).
What does a mollusk not have?
Mollusks don’t have legs, though some have flexible tentacles for sensing their environment or grabbing things. Most mollusk species grow a hard shell for protection, but their shell grows in only one or two pieces. It doesn’t have joints like the exoskeletons of insects and crustaceans .
What 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 bivalves have tentacles?
Bivalves do not have brains. Since they do not have a head region, their tentacles and eyes are often located along the mantle edge.
Do all mollusks have gills?
Respiration. Most molluscs have only one pair of gills, or even only a singular gill. Generally, the gills are rather like feathers in shape, although some species have gills with filaments on only one side. They divide the mantle cavity so water enters near the bottom and exits near the top.
Why do some mollusks have shell?
As the mollusk ages, the shell becomes thicker and sturdier. As such, older mollusks usually have strong shells. The primary purpose of the shell is protection. It protects the animal against predators and guards the internal organs.
What mollusks have no shells?
Mollusks without shells include squid, banana slugs, and octopi.
Do all molluscs have shells?
Not all mollusks have shells, however– there are plenty of species of mollusks without shells. Instead of a shell, their backs are protected by sturdy reinforced skin, scales, spines, or incomplete armored plates. The word “mollusk” comes from the Latin “molluscus,” meaning soft.
Are mollusks Autotrophs or Heterotrophs?
Yes, all mollusks are heterotrophic, because mollusks are animals, and all animals are heterotopic, meaning that they need to consume organic carbon…
Do mollusks have a cuticle?
The external cover that extends over the mantle may consist of a hardened epithelial layer called a cuticle, separate calcareous plates, or a shell.
Which of the following types of a mollusk has only one shell?
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. The word “gastropod” means “stomach foot” because most of them have their foot on the same side of their body as their stomach.
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.
Is Mollusca an exoskeleton?
Molluscs are a clade of organisms that all have soft bodies which typically have a “head” and a “foot” region. Often their bodies are covered by a hard exoskeleton, as in the shells of snails and clams or the plates of chitons.
What mollusk has eight arms and no shell?
Octopus have eight arms while squid and cuttlefish have eight arms plus two other specialized arms, called tentacles. The tentacles are adapted to snatch prey from farther away through their ability to extend and retract.
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.
Why do mollusks not have shells?
Not all mollusks have shells, however– there are plenty of species of mollusks without shells. Instead of a shell, their backs are protected by sturdy reinforced skin, scales, spines, or incomplete armored plates. The word “mollusk” comes from the Latin “molluscus,” meaning soft.
Do all mollusks have a foot?
Mollusks have a muscular foot used for locomotion and anchorage that varies in shape and function, depending on the type of mollusk under study. In shelled mollusks, this foot is usually the same size as the opening of the shell. The foot is a retractable as well as an extendable organ.
Do molluscs have jaws?
They display vivid coloration, typically seen in squids and octopi, which is used for camouflage. All animals in this class are carnivorous predators and have beak-like jaws at the anterior end.
Do all mollusks have eyes?
Diversity. There are between seven and eleven distinct eye types in molluscs. Molluscs have eyes of all levels of complexity, from the pit eyes of many gastropods, to the pinhole eyes of the Nautilus, to the lensed eyes of the other cephalopods.
What are two main parts in all 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.
What three structures do all mollusks have?
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.
What type of shells do mollusks have?
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.
Do all mollusks have bilateral 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.
What composes the shell of a mollusc?
The mineral part of the molluscan shell is typically made entirely of calcium carbonate, in particular, calcite and/or aragonite.
Do mollusks have an endoskeleton or exoskeleton?
The shells you find littered along the beach are actually the ‘skeletons’ of invertebrate animals called mollusks. 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.
Can mollusks exhibit segmentation?
Mollusks also share features of their organ systems with segmented worms. Unlike segmented worms, however, mollusks do not have body segmentation.
Do mollusks shed their shells?
Since their exoskeleton is not shed, molluscan shells must enlarge to accommodate body growth. This pattern of growth results in three distinct shell layers: an outer proteinaceous periosteum (uncalcified), a prismatic layer (calcified) and an inner pearly layer of nacre (calcified).
Do mollusks change their shells?
To make space for their growing body, molluscs have to gradually enlarge and extend their shells by adding new layers of those building blocks – calcium, carbonate and proteins. The newest part of the sea snail’s shell, for example, is around the opening where the animal pokes out.
Do mollusks have ventral nerve cords?
Mollusks have ventral nerve cords. The tissue beneath the shell is called the mantle. The mantle cavity contains hemolymph.
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.
How are mollusks and annelids different?
Most mollusks have shells. Annelids are worms such as the familiar earthworm. They have segmented bodies. Annelids look like roundworms on the outside, but on the inside they are more like mollusks.
Do molluscs have jointed limbs?
Phylum Molluska and Phylum Arthropoda are two major phyla of the Kingdom Animalia. Mollusks are soft-bodied animals with a shell while arthropods are animals with segmented bodies. They also have paired jointed appendages and an exoskeleton.
Do Mollusca have jointed appendages?
Arthropoda | Mollusca |
---|---|
Arthropods have wings to fly with jointed legs usually to their abdominal segments. | Molluscs have a muscular foot that helps in locomotion. |
Are all exoskeleton shell structure?
IN NATURE, EGGSHELLS AND THE EXOSKELETONS OF INVERTEBRATES, LIKE CRAB AND CRAYFISH SHELLS, ARE EXAMPLES OF SHELL STRUCTURES. SHELL STRUCTURES ARE MADE TO RESIST A VERY HEAVY LOAD. An eggshell is an example of a strong shell structure. A crab has an exoskeleton which is a shell structure.
Do mollusks have cartilage?
Amongst the various metazoan lineages that possess cartilage, tissues most closely resembling vertebrate hyaline cartilage in histological section are those of cephalopod molluscs. Although elements of the adult skeleton have been described, the development of these cartilages has not.
Do octopuses have arms or tentacles?
An octopus has eight appendages, each of which has rows of suckers running its length. But these are not tentacles — in strict anatomical terms, they are arms. A tentacle has suckers only on its pad-shaped ending. Squid and cuttlefish have arms, but also tentacles.
Which of the following is true of all mollusks except for cephalopods?
All mollusks except those in the class Cephalopoda have an open circulatory system. In an open circulatory system, blood is not contained entirely in enclosed blood vessels. The heart pumps blood through blood vessels that lead from the gills into body cavities called hemocoels.
Do all octopi have 8 legs?
Barring a few exceptions, octopuses have eight arms and no tentacles, while squid and cuttlefish have eight arms (or two “legs” and six “arms”) and two tentacles. The limbs of nautiluses, which number around 90 and lack suckers altogether, are called tentacles.
Where is the mantle located in most mollusks?
The mantle is all that is visible behind the head: the outer body wall and the fins are all part of the mantle. The brightly coloured mantle of a giant clam protects it from bright sunlight.
Which of the following groups are mollusks?
- Gastropods. Gastropods include snails and slugs. They use their foot to crawl. …
- Bivalves. Bivalves include clams, scallops, oysters, and mussels. …
- Cephalopods. Cephalopods include the octopus and squid.
Which characteristic do all mollusks have quizlet?
Terms in this set (29) What characteristics do all mollusks share that separate this phylum from other phyla in the kingdom Animalia? Mollusks all have a mantle, a shell secreted by the mantle, a visceral hump, a foot, and a radula.
How do you classify mollusks?
Living mollusks are usually grouped into eight classes: Gastropoda (see gastropod), Bivalvia or Pelecypoda (see bivalve), Cephalopoda (see cephalopod), Scaphopoda (tusk shells), Aplacophora (Solenogasters), Caudofoveata (sometimes included in the Aplacophora order), Polyplacophora (chitons), and Monoplacophora.
Why do mollusks have eyes?
Hence, eyes are important for clams through which the bivalves can avoid being easy prey. A large shadow over the bivalves can mean that clams have an approaching predator.
Do mollusk eyes have a blind spot?
The nerve fibers of the molluscan eye don’t have to pass through the retina to enter the visual cortex of the brain, they are already on that side of it. By contrast, the neural elements of the vertebrate eye must pass through, and that’s what makes the blind spot. Molluscan eyes have no blind spot.
Which mollusk has the largest eye of all animals?
The eye diameter of the giant squid, which measures up to 27 cm (10.6 inches), is among the largest of all living animals; it is second only to that of the colossal squid.
What characteristic is common to all mollusks?
There are only three characteristics shared by all living mollusks: the presence of a mantle (the rear covering of the body) that secretes calcareous (e.g., calcium-containing) structures; the genitals and anus opening into the mantle cavity; and paired nerve cords.
What structures do all molluscs 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.
How do Cephalopods differ from other molluscs?
The most obvious difference between most cephalopods and other mollusks is the apparent lack of a shell. Octopuses do not have shells at all, while squids have a small internal shell. (Nautiluses, which are found in the South Pacific and Indian oceans, are the only cephalopods with an external shell.
Do all mollusks have shells?
Not all mollusks have shells, however– there are plenty of species of mollusks without shells. Instead of a shell, their backs are protected by sturdy reinforced skin, scales, spines, or incomplete armored plates. The word “mollusk” comes from the Latin “molluscus,” meaning soft.
How molluscs differ from other phylum describe?
Although there is no single feature that all molluscs possess, three features are so common in molluscs that they are used to distinguish them from organisms in other phyla: All molluscs have a specialized foot used in digging, grasping, or creeping.
Does a Polyplacophora have tentacles?
Chitons do not have cephalic eyes or tentacles, and the head is located on the underside of the body, anterior to the broad muscular foot.