Final Review

Question 1

Anamorphosis

Answer 1

A type of post-embryonic development in which additional body segments are added over time as the organism grows. Seen in Myriapoda like millipedes.

Question 2

Ambulacrum

Answer 2

A region in echinoderms where tube feet are located. These areas are used for locomotion, feeding, and sensory functions.

Question 3

Appendicularia

Answer 3

A class within Urochordata (Tunicates) also known as Larvaceans. They retain larval features throughout life and create mucous “houses” to filter feed.

Question 4

Aristotle’s Lantern

Answer 4

A five-toothed, ornate mouthpart structure found in Echinoidea (sea urchins) used for scraping and feeding.

Question 5

Axocoel

Answer 5

One of the three paired coelomic compartments in echinoderm larvae, involved in early body cavity development and metamorphosis.

Question 6

Basal Mat

Answer 6

In colonial tunicates, it’s a base structure from which multiple zooids grow and remain embedded, helping maintain their colony structure.

Question 7

Book lungs/gills

Answer 7

Both are respiratory structures found in arthropods, named for their stacked, page-like appearance (lamellae) that increases surface area for gas exchange.

Question 8

Buccal Cirri

Answer 8

Slender, sensory tentacle-like structures near the mouth of lancelets (Cephalochordata), used to filter out large particles from entering the pharynx.

Question 9

Bursae

Answer 9

Sac-like structures found in brittle stars (Ophiuroidea), used for respiration and sometimes for brooding young.

Question 10

Cardiac Stomach

Answer 10

The stomach in sea stars (Asteroidea) that can be everted to externally digest food before pulling it back in.

Question 11

Cirri

Answer 11

Filamentous appendages, often sensory or for feeding, found in various invertebrates including crinoids and lancelets.

Question 12

Collum

Answer 12

The first body segment behind the head in millipedes (Diplopoda), typically thickened and collar-like

Question 13

Colonial tunicates

Answer 13

Tunicates that form colonies by asexual budding; zooids are embedded in a shared tunic and often share circulatory systems.

Question 14

Cuvierian Tubules

Answer 14

Defensive structures found in some sea cucumbers (Holothuroidea) that are ejected through the anus as sticky or toxic threads to deter predators.

Question 15

Dorsal Tergites

Answer 15

The dorsal (upper) hardened plates on each body segment of arthropods like millipedes and centipedes

Question 16

Elytra

Answer 16

Hardened forewings found in Coleoptera (beetles), used as protective covers for the membranous hindwings.

Question 17

Endocrine System

Answer 17

The hormone-secreting system, which regulates growth (e.g., ecdysone for molting) and reproduction (e.g., pheromones).

Question 18

Epicuticle

Answer 18

The outermost layer of the arthropod cuticle, which may contain waxy lipids to prevent desiccation (drying out).

Question 19

Eversible Stomach

Answer 19

A stomach that can be turned inside-out through the mouth, used by sea stars to externally digest prey like mussels.

Question 20

Exoskeleton

Answer 20

A rigid external skeleton made of chitin found in arthropods that provides support and protection.

Question 21

Fissiparity

Answer 21

Common in some echinoderms like sea stars and brittle stars. The organism must retain some part of the nerve ring or essential tissues to successfully regenerate. A form of asexual reproduction where an organism splits into two or more parts, and each part regenerates into a complete individual.

Question 22

Gastric Caeca

Answer 22

As seen in Hexapoda, these increase surface area for digestion and absorption. (Caecum)

Question 23

Gnathobase

Answer 23

Tooth-like or grinding structures located at the base of Chelicerate appendages, especially near the mouth.

Question 24

Halteres

Answer 24

Modified hindwings in Diptera (true flies) used for balance during flight

Question 25

Hydrocoel

Answer 25

A coelomic compartment in echinoderm larvae that becomes the water vascular system during metamorphosis.

Question 26

Indirect copulation

Answer 26

A reproductive strategy where sperm is transferred without direct physical mating. The male deposits a spermatophore (a packet of sperm), and the female later picks it up. (as seen in Arachnids and Chilopoda)

Question 27

Lateral spiracles

Answer 27

External openings on the sides of some arthropods (like centipedes) that connect to internal tracheae for respiration.

Question 28

Malpighian tubules

Answer 28

Excretory structures found in most terrestrial arthropods (especially Hexapoda), used to remove nitrogenous wastes with minimal water loss.

Question 29

Mandibles

Answer 29

Jaw-like mouthparts in arthropods used for biting, cutting, or crushing food.

Question 30

Metapleural folds

Answer 30

Lateral folds or flaps in lancelets (Cephalochordata) that are associated with respiration or circulation.

Question 31

Myotome

Answer 31

Repeated blocks of skeletal muscle found in lancelets and other chordates, used for swimming.

Question 32

Nerve Net

Answer 32

A decentralized nerve system characteristic of radially symmetrical animals like echinoderms (especially in early development).

Question 33

Nerve Ring

Answer 33

A circular nerve structure found in echinoderms, connecting radial nerves and coordinating movements like tube feet operation

Question 34

Ossicles

Answer 34

Calcareous elements forming the internal skeleton of echinoderms (e.g., sea urchins and sea stars).

Question 35

Papulae

Answer 35

Thin-walled, finger-like extensions of the body wall in sea stars used for gas exchange (aka dermal branchiae or skin gills).

Question 36

Paranotal lobes

Answer 36

Hypothesized ancestral flaps on the thorax of insects thought to be precursors to wings (Novel Structure Hypothesis).

Question 37

Pedicellariae

Answer 37

Small pincer-like appendages found on the surface of some echinoderms, particularly sea stars (Asteroidea) and sea urchins (Echinoidea). They provide protection and hygiene.

Question 38

Pedipalps

Answer 38

A pair of appendages located near the mouth of chelicerates, transfer sperm, manipulate food, and sensory detection

Question 39

Pleuron

Answer 39

The lateral portion of the body wall on each thoracic segment of an insect.

Question 40

Pyloric Stomach

Answer 40

In sea stars, the second stomach (after the cardiac) responsible for enzymatic digestion and nutrient absorption.

Question 41

Radial Canals

Answer 41

Extensions of the echinoderm water vascular system that run along each arm and connect to the tube feet.

Question 42

Respiration strategies

Answer 42

Echinodermata using structures like papulae, bursae, or the respiratory tree

Question 43

Rolling behavior

Answer 43

A defense strategy used by millipedes where they curl into a tight coil to protect their softer underside.

Question 44

Silk glands

Answer 44

Glands in spiders (Araneae) that produce silk proteins (like spidroin) for web-building and other purposes.

Question 45

Spiracles

Answer 45

External respiratory openings in arthropods that lead to internal tracheal tubes; they can be open/closed to regulate gas exchange and water loss.

Question 46

Spinnerets

Answer 46

Specialized abdominal appendages in spiders (Araneae) used to extrude silk. Spinnerets contain spigots, which connect to silk glands that produce different types of silk for webs,

Question 47

Spigot

Answer 47

Tiny nozzles or outlets on spinnerets through which silk (spidroin) is secreted.

Question 48

Statocysts

Answer 48

Balance-sensing organs found in echinoderms and other invertebrates.

Question 49

Stridulation

Answer 49

Sound production by rubbing together certain body parts, common in insects like crickets

Question 50

Supraesophageal ganglion

Answer 50

The “brain” of arthropods, located above the esophagus and responsible for processing sensory information.

Question 51

Suspension feeders

Answer 51

Organisms that filter food particles from water, such as crinoids, larvaceans, and tunicates.

Question 52

Tentacles

Answer 52

Elongated, flexible appendages used for feeding, sensing, or movement (seen in tunicates, sea cucumbers, and others).

Question 53

Thanatosis

Answer 53

A defense behavior also known as “playing dead”, where an animal becomes immobile to avoid predation.

Question 54

Tymbal

Answer 54

A sound-producing membrane in certain insects (e.g., cicadas) that vibrates when muscles contract.

Question 55

Tunic

Answer 55

A protective outer covering found in Urochordates (tunicates), made of tunicin, a cellulose-like carbohydrate. Providing structural support and protection. It may also house symbiotic or colonial organisms.

Question 56

Velar tentacles

Answer 56

Sensory and feeding structures located near the velum (soft palate-like area), possibly in tunicate larvae or filter-feeding chordates.

Question 57

Ventral nerve cord

Answer 57

The main nerve cord running along the belly (ventral) side of arthropods, part of their central nervous system.

Question 58

Wheel Organ

Answer 58

A ciliated structure in lancelets (Cephalochordata) used to create water currents and help direct food particles toward the mouth.

Question 59

Zooids

Answer 59

Individual animals that are part of a colonial organism, such as in colonial tunicates. Each zooid may have its own feeding and reproductive organs.