BIOL 1123 – EXAM 3 Zoology Study Guide

Comprehensive vocabulary flashcards outlining terminology, physiological mechanisms, and anatomical structures for BIOL 1123 Zoology Exam 3.

Metamerism

A body organization made of repeated sections, similar to links in a chain.

Tagmatization

The grouping of repeated body sections into larger, specialized regions with distinct functional roles.

Cuticle

A protective outer layer produced by the skin-like outer cells of an animal.

Ecdysis

The shedding of an animal's old outer covering (molting) to permit body growth.

Hemocoel

An internal body cavity in certain animals where blood-like fluid flows freely and directly bathes organs.

Chelicerae

The first pair of mouth appendages in spiders and related arachnids, functioning as fangs or pincers.

Pedipalps

The second pair of appendages near the mouth in arachnids, used for touch, sensory reception, holding food, or mating.

Coxal glands

Excretory organs present in some arachnids that remove metabolic waste and maintain water and salt balance.

Malpighian tubules

Slender excretory tubules in insects that extract nitrogenous waste from hemolymph and empty it into the digestive tract.

Spermatophores

Small packaged capsules carrying sperm that are transferred directly to a female or deposited for her to pick up.

Biramous

Describing an appendage that branches into two distinct paths or parts.

Uniramous

Describing an appendage that consists of a single unbranched structure.

Shivering thermogenesis

Rapid, involuntary muscle contractions that generate metabolic heat.

Pheromones

Chemical signals released by an animal to communicate messages to conspecifics.

Notochord

A flexible, longitudinal support rod characteristic of chordate embryos and retained in some adult chordates.

Pharyngeal slits

Openings or grooves situated in the throat region of chordates, functioning in feeding or gas exchange in aquatic species.

Muscular foot

One of the three primary body parts of a mollusk, adapted primarily for locomotion.

Visceral mass

The central body area of a mollusk that contains the majority of internal organs, including digestive and reproductive structures.

Mantle

A tissue layer in mollusks that covers the visceral mass and typically secretes the shell.

Radula

A rasplike, toothed chitinous ribbon found in the mouths of most mollusks (absent in bivalves) used to scrape or slice food.

Mantle cavity

The space enclosed under the mantle in mollusks that houses respiratory structures like gills or lung surfaces.

Nephridia / metanephridia

Excretory structures in mollusks that filter coelomic fluid, remove metabolic wastes, and regulate osmotic balance.

Torsion

A developmental event in gastropods where the visceral mass rotates approximately 180 degrees, orienting the mantle cavity and anus toward the anterior.

Siphons

Tubular structures in bivalves through which water is drawn in (incurrent) and expelled (excurrent).

Glochidia

Specialized, parasitic larval forms of freshwater mussels that temporarily attach to fish fins or gills for dispersal.

Jet propulsion

A mode of locomotion in cephalopods achieved by forcing water rapidly out of the funnel, driving the animal in the opposite direction.

Closed circulatory system

A circulatory arrangement where blood is entirely confined within a network of continuous vessels, characteristic of cephalopods.

Epicuticle

The thin, outermost layer of the arthropod exoskeleton responsible for waterproofing and barrier protection.

Procuticle

The thick inner section of the arthropod cuticle, subdivided into an outer exocuticle and an inner endocuticle.

Metamorphosis

A prominent structural transformation in body morphology occurring between the juvenile and adult life stages.

Prosoma

The anterior body region of chelicerates, forming the protective cephalothoracic shield in horseshoe crabs.

Opisthosoma

The posterior abdominal body region of chelicerates.

Telson

The terminal spine of a horseshoe crab used primarily to right itself when overturned, rather than delivering venom.

Book gills

External, layered leaflike respiratory organs located beneath the abdomen of horseshoe crabs.

Book lungs

Internal respiratory organs in arachnids containing stacked, leaflike vascular plates across which gas exchange occurs.

Carapace

A rigid, protective dorsal shield of cuticle covering the cephalothorax in many crustaceans.

Green glands (antennal glands)

Paired excretory structures in decapod crustaceans like crayfish that filter wastes and manage osmoregulation.

Direct flight muscles

Flight muscles in insects that attach straight to the base of the wings to actuate wing movement.

Indirect flight muscles

Flight muscles that move insect wings indirectly by distorting and altering the mechanical shape of the thoracic body wall.

Spiracles

External surface pores along the pleural walls of insects through which air enters the tracheal system.

Tracheae

Branching, internal tubular networks that deliver gaseous oxygen directly to insect body tissues.

Ecdysone

An insect hormone that initiates and regulates the molting process.

Juvenile hormone

An insect hormone that maintains nymphal or larval characteristics and regulates advancement toward sexual maturity.

Ametabolous

A developmental pattern with negligible metamorphosis where newly hatched juveniles appear as miniature replicas of the adult.

Hemimetabolous

Incomplete metamorphosis proceeding through egg, nymph, and adult stages without an intervening pupal phase.

Holometabolous

Complete metamorphosis consisting of four distinct lifecycle stages: egg, larva, pupa, and adult.

Hemiptera

The taxonomic order containing true bugs, diagnosed by piercing-sucking feeding mouthparts.

Cryptobiosis

A state of suspended metabolic animation enabling tardigrades to withstand extreme environmental stress.

Lobopods

Fleshy, stubby, unjointed walking appendages characteristic of velvet worms (Phylum Onychophora).

Pentaradial symmetry

A form of radial symmetry arranged in five distinct sections around a central axis, typical of adult echinoderms.

Ossicles

Microscopic to fused plates composed of calcium carbonate that constitute the endoskeleton of echinoderms.

Water vascular system

A hydraulic network of fluid-filled canals unique to echinoderms, driving tube foot extension, locomotion, and feeding.

Madreporite

A porous, sieve-like plate on the aboral surface of echinoderms serving as the intake port for the water vascular system.

Ampullae

Bulb-like muscular reservoirs in echinoderms that contract to force fluid into and extend the tube feet.

Aristotle's lantern

A complex, five-toothed skeletal chewing and scraping apparatus characteristic of regular sea urchins (Echinoidea).

Deuterostome

An animal lineage characterized by an embryonic pattern where the initial blastopore opening develops into the anus, with the mouth developing secondarily.

Proboscis

The muscular, anterior-most anatomical division of hemichordates used for burrowing, food capture, and sensing.

Collar

The short intermediate anatomical section of a hemichordate immediately following the proboscis, flanking the mouth.

Trunk

The elongate posterior section of a hemichordate housing the visceral organs, gill slits, and gonads.

Tornaria

The free-swimming, ciliated planktonic larva produced by many species of enteropneust acorn worms.