Mollusks and Echinoderms Quiz

Animals without a backbone, encompassing most animal phyla except part of phylum Chordata.

Sponges; aquatic animals; lack true tissues; suspension feeders.

Animals with two body forms (polyp and medusa); predatory; use cnidocytes on tentacles.

A major animal group; some have lophophores (feeding structures) or trochophore larvae, not both.

Flatworms, mostly free-living or parasitic; dorsoventrally flattened bodies.

Animals without a body cavity (coelom)

An animal that feeds on food particles suspended in water

A simple nervous system lacking a central brain, found in some invertebrates like cnidarians.

A rasping, tongue-like structure in mollusks used for scraping food, found in gastropods and chitons, but not bivalves.

A developmental process in gastropods where the body twists 180 degrees, resulting in the anus and mantle cavity being located above the head.

Bivalves are suspension feeders, meaning they filter food particles from the water using their gills.

Tough, silky threads secreted by bivalves, used for attaching to rocks or pilings.

A fleshy covering that encloses the visceral mass in cephalopods, also forming the shell (when present).

A free-living flatworm, moves using cilia on a slime trail, has eyespots and lateral flaps for detecting smell, and can reproduce sexually or asexually.

Internal parasitic flatworms, specialized for reproduction, with complex life cycles involving both sexual and asexual stages, and sometimes intermediate hosts.

Parasitic flatworms without a digestive system that use a scolex with hooks to attach themselves to their host.

Microscopic multicellular animals, mostly aquatic, with a complete digestive tract and a fluid-filled pseudocoelom acting as a circulatory system. They often reproduce asexually.

Animals with a lophophore. This is a crown of tentacles around their mouth. They have a true coelom, and include ectoprocts and brachiopods

Sessile colonial animals resembling plants, encased in a hard exoskeleton, and found in both fresh and saltwater.

Marine animals that resemble clams, but have dorsal and ventral shells, often attached to the seafloor by a stalk.

A large diverse group of organisms, mostly marine, with a hard calcium carbonate shell in many types, and a larval planktonic stage (trochophore).

A clade of annelids that are mostly mobile, marine organisms with paddle-like appendages called parapodia.

A clade of annelids that are typically less mobile than errantians, often burrowing or living in protective tubes.

Paddle-like or ridge-like structures found on each segment of many errantian annelids, aiding in movement and locomotion.

Bristles made of chitin, found on the parapodia of errantian annelids, providing grip and traction.

Leeches are a group belonging to the Sedentaria clade, known for their blood-sucking habits and the presence of suckers at both ends of their bodies.

A type of insect development involving four stages: egg, larva, pupa, and adult. During metamorphosis, the insect undergoes significant physical changes.

Groups of insects classified based on shared characteristics, such as wing structure, mouthparts, and life cycle.

The order of beetles, characterized by hardened forewings called elytra that protect the hind wings.

The order of true bugs, known for their piercing-sucking mouthparts and often having wings with hardened bases.

The order of bees, ants, and wasps, characterized by membranous wings and a stinger (in females).

The order of butterflies and moths, known for their colorful wings covered in scales.

The order of dragonflies and damselflies, characterized by their large, transparent wings.

The order of crickets, grasshoppers, mantids, and roaches, known for their strong hind legs for jumping.

The order of lice, wingless parasites that feed on blood of mammals and birds.

The order of fleas, wingless parasites that feed on blood of mammals and birds, known for their jumping ability.

A network of hydraulic canals and tube feet found in echinoderms, used for gas exchange, locomotion, and feeding.

A small, muscular, fluid-filled extension of the water vascular system in echinoderms, used for locomotion, feeding, and gas exchange.

Asteroidea (sea stars) have a central disc and five arms that are not sharply distinct from the body. Ophiuroidea (brittle stars) have a distinct central disc and five long, flexible arms.

This class of echinoderms includes sea urchins and sand dollars. They have a round body with spines and a mouth on the underside.

This class of echinoderms includes sea cucumbers. They have a long, soft body and are often found on the ocean floor.

Chitons are marine mollusks with a shell composed of eight plates. They are grazers, using their radula to scrape algae off rocks.

Cephalopods are marine mollusks, including octopuses, squids, and nautiluses. They have a reduced or internal shell, a mantle covering the visceral mass, and tentacles with beaks for hunting.

Annelids are segmented worms, commonly known as earthworms. They have a closed circulatory system, a complex digestive system, and reproduce both sexually and asexually.

Animals that are permanently attached to a surface and cannot move freely. They include sponges and many cnidarians like corals.

An organism that has both male and female reproductive organs. Some sponges and other invertebrates are this.

A specialized stinging cell found in cnidarians such as jellyfish and sea anemones. It helps them capture prey.

A free-swimming larval stage found in some invertebrates, like mollusks and annelids, characterized by a ring of cilia around the body.

A body shape that is flattened along the top-bottom axis, like flatworms. This allows for better surface area for gas exchange and movement across surfaces.

Bristles made of chitin, found on the parapodia of errantian annelids, providing grip and traction.

Leeches are a group belonging to the Sedentaria clade, known for their blood-sucking habits and the presence of suckers at both ends of their bodies.

Barnacles, a group of marine crustaceans that are sessile as adults, attached to rocks, ships, or other surfaces. They filter feed using feathery appendages called cirri.

A diverse group of marine animals that are bilaterally symmetrical as larvae and radially symmetrical as adults. They have a unique water vascular system that helps them move, feed, and exchange gas.

A network of canals and tube feet found in echinoderms. It uses hydraulic pressure to help with movement, feeding, and gas exchange.

Sea stars, characterized by a central disc and five arms (not sharply distinct from the body). They have a tube foot system for movement, feeding, and gas exchange.

Brittle stars, characterized by a distinct central disc and five long, flexible arms. They are efficient predators, using their arms to capture prey.

Phylum of roundworms, characterized by unsegmented bodies, tapered at both ends, and a fluid-filled pseudocoelom. They can be parasitic or free-living.

Phylum of animals with a segmented body, hard exoskeleton, and jointed appendages. They are extremely diverse and abundant, including insects, spiders, crustaceans, and millipedes.

A class of arthropods that includes spiders, scorpions, ticks, and mites. They have a cephalothorax, chelicerae, pedipalps, and four pairs of legs.

A class of arthropods that includes centipedes and millipedes, characterized by many legs and a segmented body.

A class of arthropods that includes insects, characterized by three pairs of legs and often wings. They are incredibly diverse and found in nearly all terrestrial environments.

Incomplete metamorphosis is seen in insects like grasshoppers, where the young (nymphs) resemble smaller versions of adults and molt several times. Complete metamorphosis involves a larval stage (caterpillar), followed by a pupal stage (chrysalis) before reaching the adult stage. This pattern is seen in butterflies, moths, and beetles.

Arthropods are distinguished by segmented bodies (head, thorax, abdomen), hard exoskeletons requiring molting, and jointed appendages. This body plan has proven successful since the Cambrian explosion.

Most arthropods use a system of tracheae, branching tubes that connect to the external environment through openings called spiracles.

The order of beetles, known for their hardened forewings, called elytra, which protect the hind wings.

The order of true bugs, characterized by piercing-sucking mouthparts and wings with hardened bases.

The order of bees, ants, and wasps, known for their membranous wings and, in females, a stinger.

The order of butterflies and moths, characterized by colorful wings covered in scales.

The order of dragonflies and damselflies, known for their large, transparent wings.

The order of crickets, grasshoppers, mantids, and roaches, known for strong hind legs for jumping.

The class of crustaceans that includes isopods, amphipods, and decapods, featuring diverse body forms and extensive appendages.

The order of crustaceans that includes crabs, shrimp, lobsters, and crayfish, characterized by ten walking legs.

The class of crustaceans, known as copepods, that are the most abundant primary consumers in oceans.