Pre- Lab Quiz 5

Vocabulary flashcards covering key terms related to the phyla Mollusca and Annelida, including their body plans, classes, and specific anatomical features.

Phylum Mollusca

A diverse phylum of invertebrates including snails, clams, octopuses, and squids, characterized by a soft body, often enclosed in a calcium-based shell. This has 4 classes

Phylum Annelida

A phylum of segmented worms with 3 class that are divided by septa including earthworms, leeches, and polychaetes, characterized by a coelom and a closed circulatory system.

Coelomate

An animal that possesses a true coelom, a body cavity completely lined by mesoderm.

Protostome

A group of coelomate animals where cleavage is spiral and determinate, the blastopore becomes the mouth, and the coelom forms by a splitting of the mesoderm.

Deuterostome

A group of coelomate animals where cleavage is radial and indeterminate, the blastopore becomes the anus, and the coelom forms by an outpocketing of the primitive gut.

Mantle (Mollusca)

A specialized layer of epidermal cells in mollusks that secretes the shell and may aid in respiration and locomotion.

Open Circulatory System (Mollusca)

A circulatory system commonly found in mollusks where hemolymph bathes the organs directly within a body cavity called a hemocoel.

Phylum Mollusca Body Plan

Characterized by a visceral mass containing organ systems and sensory structures, a ventral muscular foot for locomotion, a calcium-based shell (sometimes absent), and a mantle that secretes the shell and potentially aids in respiration and locomotion.

Class Polyplacophora

A class of primitive marine mollusks, commonly called chitons, characterized by a dorsal shell divided into 8 plates. They use the ventral foot for locomotion and the radula (rasping tongue) to help assist in scraping food from the rocks. “many plates move”

Class Gastropoda

A class of mollusks including snails, slugs, and nudibranchs, most of which have a coiled shell, but some do not produce one. “stomach foot” 

Class Bivalvia

A class of mollusks including clams, oysters, scallops, and mussels, characterized by a dorsally hinged shell in two parts. Most of these produce pearls when an irritant (such as a grain of sand) lodges between mantle and shell.

Class Cephalopoda

A class of mollusks including squids, octopuses, nautilus, and cuttlefish, where the foot is modified into tentacles and shells may be internal or absent. “head foot”

Phylum Annelida

A segmented Phylum that has about 12,000 species like earthworms, polychaetes, and leeches. Each bodily segment, is divided by septa and contains parts of the circulatory, digestive, nervous, and excretory systems. It is a closed circulatory system, and most members have small, paired bristle like apendages called setae.

Class Polychaeta

An  Annelida class of marine annelids (e.g., clam worms), characterized by many setae and fleshy parapodia on each segment.   “many setae”

Class Hirudinea

A class of annelids commonly known as leeches, primarily freshwater ectoparasites, characterized by less apparent segmentation, lack of setae, and anterior/posterior suckers. They are hermaphodic

Class Oligochaeta

A class of annelids including earthworms and many freshwater species, characterized by lacking parapodia and having few setae. This is hermaphrodic.

Earthworm Locomotion

A method of movement in earthworms involving alternating contractions of circular and longitudinal muscles, leading to extension, anchoring, and contraction.

Seminal Receptacles (Earthworm)

Organs in earthworms that store sperm received from another earthworm during copulation.

Siphon (Squid)

A muscular funnel in squids and other cephalopods used for jet propulsion by expelling water.

Mantle (Squid)

The main body wall of a squid, covering the visceral mass and involved in respiration and locomotion.

Tentacles (Squid)

Longer, retractable appendages in squids, often ending in a club with suckers, used for catching distant prey.

Ink Sac (Squid)

An organ in squids that contains dark ink, expelled when threatened to create a diversion.

Ctenidium (Squid)

Feathery respiratory organs (gills) in squids, located within the mantle cavity, used for gas exchange.

Branchial Heart (Squid)

Accessory hearts in squids that pump blood through the gills to increase oxygen uptake.