Mollusk Anatomy & Classification Quiz (30 Questions)

Among the three groups of annelids, polychaetes are known to be broadcast spawners, releasing eggs and sperm into the water to increase chances of fertilization.

The correct answer is that a larva may be a herbivore because larva refers to the juvenile form of an insect that undergoes metamorphosis. Larvae can have various diets including herbivorous, carnivorous, or omnivorous.

Mollusks are highly diverse in terms of their physical characteristics (morphology), how they obtain nutrients (modes of nutrition), reproduction methods, and how they respond to their environment. These aspects contribute to the vast diversity seen within the mollusk phylum.

The correct answer describes the characteristics of the phylum Mollusca, which include being bilaterally symmetrical, triploblastic, and coelomate protostomes. The incorrect answers provided do not accurately reflect these characteristics and therefore are not correct responses.

Mollusks are classified into four major groups: Polyplacophora, Gastropoda, Bivalvia, and Cephalopoda. The incorrect answers provided do not belong to the major groups of mollusks and are part of other phyla or classes in the animal kingdom.

The body plan of a mollusk typically consists of a visceral mass, mantle, and foot, which are key features of their anatomy and functionality.

Polyplacophorans, also known as chitons, are marine mollusks known for their unique characteristics such as a large muscular foot, ability to roll into a ball, gills located in mantle grooves, omnivorous diet, segmented shell, and radula that scrapes algae and bryozoans.

Bivalvia are characterized by having a mantle cavity modified by siphons, an enlargement of gills, being relatively sessile, functioning as filter feeders, and engaging in broadcast spawning. The incorrect answers provided do not align with the typical characteristics of Bivalvia.

Siphons are actually extensions of the posterior mantle in certain mollusks that help in filtering food particles from water flowing through the mantle cavity.

The foot in bivalves is primarily used for anchoring themselves in place and for digging into the substrate.

The adductor muscles in scallops are primarily responsible for closing and holding the shell together as a defense mechanism.

Mantle lined eyes in scallops are specialized to detect motion and light, helping the scallops avoid predators and navigate their surroundings.

Gastropoda, which includes slugs, are known for their herbivorous and predatory feeding habits, possess a more complex head structure, and typically engage in internal and external fertilization. They exhibit either dioecious reproduction (separate individuals having male or female gonads) or hermaphroditic characteristics. Contrary to the incorrect answers provided, slugs cannot produce both eggs and sperm simultaneously, do not solely rely on asexual reproduction, and do not have a simplistic head or exclusively use external fertilization methods.

Torsion refers to the twisting of the body in a 180-degree rotation, specifically in reference to some mollusks where the mantle cavity and anus are moved over the head. It is a specific biological process that is distinct from other unrelated processes mentioned in the incorrect answers.

The coiling phenomenon refers to the twisting or coiling of the visceral mass, which is the internal organs collectively located in the main cavities of the body.

After torsion, elongation and coiling occur as a result of the twisting or winding force applied to an object.

Cephalopods are characterized by having an enlarged head and a reduced or absent external shell.

Cephalopods, such as octopuses and squids, are known to be predators in their marine environments due to their excellent vision which helps them hunt and catch prey efficiently. Their ability to change color and texture allows them to camouflage themselves from predators.

Cephalopods, such as octopus and squid, use their ink sacs to create a cloud of ink to escape from predators or confuse them.

Cephalopods, such as octopus and cuttlefish, demonstrate visual communication through the use of chromatophores on their skin to change colors and textures, allowing them to blend in with their environment, communicate with one another, and even hypnotize their prey.

Cephalopods, such as squids and octopuses, have a closed circulatory system where blood remains enclosed in vessels and is distinct from the interstitial fluid. This efficient system allows for quicker circulation and higher metabolic rates.

Jet propulsion is typically achieved using a combination of mantle and siphon to create thrust for aircraft or other vehicles.

Arms with suckers and or nodes typically have 2 elongated tentacles for grasping and manipulation.

Cephalopods have separate sexes (male and female) and engage in elaborate courtship behaviors. They reproduce through internal fertilization, where the male transfers sperm to the female's body for fertilization.

Cephalopod males transfer sperm via a specialized arm-hectocotylus, which is specifically adapted for this purpose.

Female insects often sacrifice their own lives after laying eggs or when the eggs hatch as part of their reproductive strategy.

Cephalopods are a class of marine animals that include nautilus and ammonite, among others. Starfish, jellyfish, and hermit crab are not examples of cephalopods.

Mollusks are often utilized for various purposes such as food, jewelry, serving as vectors for parasites, and as exotic invasive species. They are not typically used for building materials, fuel source, or medical treatments.

The correct answer is 'receive, process and relay information.' The nervous system is responsible for transmitting signals between different parts of the body to coordinate the actions of the various parts.

The correct answer should be CNS (Central Nervous System) and PNS (Peripheral Nervous System). The other options mentioned do not represent actual nervous systems.