Animal Diversity I & Ii

Front 1

acoelomate

Back 1

An animal lacking a body cavity.

Front 2

ampulla

Back 2

Any small, sac like extension, e.g., the expanded structure at the end of each semicircular canal of the ear.

Front 3

archenteron

Back 3

The central cavity of the gastrula stage of embryonic development that is lined with endoderm; primitive digestive system.

Front 4

axopod

Back 4

Long, filamentous, cytoplasmic projections characteristic of actinopods.

Front 5

blastopore

Back 5

The primitive opening into the body cavity of an early embryo that may become the mouth (in protostomes) or anus (in deuterostomes) of the adult organism.

Front 6

cephalization

Back 6

The evolution of a head; the concentration of nervous tissue and sense organs at the front end of the animal.

Front 7

chelicerae

Back 7

The first pair of appendages in certain arthropods; claw like appendages located immediately anterior to the mouth and used to manipulate food into the mouth.

Front 8

choanocyte or collar cells

Back 8

Flagellate cells that make up the inner layer of certain sponges. Each cell is equipped with a tiny collar surrounding the base of the flagellum. The collar is an extension of the plasma membrane and consists of microvilla. Collar cells create the water current that brings food and oxygen to the cells and carries away carbon dioxide and other wastes. Collar cells also trap phagocytized food particles.

Front 9

cilia

Back 9

One of many short, hairlike structures that project from the surface of some eukaryotic cells and are used for locomotion or movement of materials across the cell surface. (Ciliates use this for locomotion)

Front 10

What's the difference between and open and closed circulatory system?

Back 10

Open C.C.- The blood bathes the tissues directly; characteristic of arthropods and many mollusks.
Closed C.C.- The blood flows through a continuous circuit of blood vessels; characteristic of annelids, cephalopods, and vertebrates.

Front 11

cnidocyte

Back 11

Stinging cells characteristic of cnidarians which contain nematocyst which is used for anchorage, defense, and capturing prey.

Front 12

deuterostome

Back 12

Major division of the animal kingdom in which the anus develops from the blastopore; includes echinoderms and chordates.

Front 13

What is the difference between a complete and an incomplete digestive system?

Back 13

In a complete digestive system, there are two openings so the food or waste only travels in one direction (one way). In an incomplete digestive system, there is only one opening so the food or waste must travel back to the same opening it came in from.

Front 14

dorsal, hollow nerve cord

Back 14

Located in lancelets; contains specialized regions that correspond to the vertebrate forebrain and midbrain.

Front 15

ectoderm

Back 15

The outer germ layer of the early embryo; gives rise to the skin and nervous system.

Front 16

endoderm

Back 16

The inner germ layer of the early embryo; becomes the lining of the digestive tract and the structures that develop from the digestive tract- liver, lungs, and pancreas.

Front 17

epidermis

Back 17

An outer layer of cells that covers the body of plants and functions primarily for protection.

Front 18

flagellum

Back 18

A long, whip-like structure extending from certain cells and used in locomotion. Eukaryote flagella consist of two central, single microtubules surrounded by nine double microtubules (9+2 structure), all covered by a plasma membrane. Prokaryote flagella are filaments rotated by special structures located in the plasma membrane and cell wall.

Front 19

foot (of mollusk)

Back 19

Broad, flat, muscular foot is located ventrally and is used for locomotion.

Front 20

gastrodermis

Back 20

The endoderm gives rise to the inner gastrodermis, which lines the gastrovascular cavity and functions in digestion.

Front 21

gastrovascular cavity

Back 21

A central digestive cavity with a single opening that functions as both mouth and anus; characteristic of cnidarians and flatworms.

Front 22

hemocoel

Back 22

Blood cavity characteristic of animals with an open circulatory system.

Front 23

hydrostatic skeleton

Back 23

A type of skeleton found in some invertebrates in which contracting muscles push against a tube of fluid.

Front 24

ingestion

Back 24

The process of taking food(or other material) into the body.

Front 25

macronucleus

Back 25

A large nucleus found, along with one or several micronuclei, in ciliates. The macronucleus regulates metabolism and growth.

Front 26

micronucleus

Back 26

One or more smaller nuclei found, along with the macronucleus, in ciliates. The micronucleus is involved in sexual reproduction.

Front 27

mantle (of mollusk)

Back 27

A fold of tissue that covers the visceral mass and that usually produces a shell.

Front 28

medusa

Back 28

A jellyfish-like animal; a free-swimming, umbrella-shaped stage in the life cycle of certain cnidarians.

Front 29

mesoderm

Back 29

The middle germ layer of the early embryo; gives rise to connective tissue, muscle, bone, blood vessels, kidneys, and many other structures.

Front 30

mesoglea

Back 30

Gastrodermis and Epidermis is separated by a gelatinous, mainly acellular mesoglea.

Front 31

mesohyl

Back 31

Between the outer and inner cell layers of the sponge body is a gelatin-like layer, the mesohyl, supported by slender skeletal spikes called spicules.

Front 32

notochord

Back 32

The flexible, longitudinal rod in the anterior-posterior axis that serves as an internal skeleton in the embryos of all chordates and in the adults of some.

Front 33

parapodia

Back 33

Paired, thickly bristled paddle like appendages extending laterally from each segment of polychaete worms.

Front 34

pharyngeal slits

Back 34

Openings that lead from the pharyngeal cavity to the outside; evolved as part of a filter-feeding system in chordates and later became modified for other functions, including gill slits in many aquatic vertebrates

Front 35

polyp

Back 35

A hydra like animal; the sessile stage of the life cycle of certain cnidarians.

Front 36

porocyte

Back 36

Specialized tube like cells that form the pores of a simple sponge.

Front 37

postanal tail

Back 37

Chordates have a larva or embryo with a muscular post anal tail, an appendage that extends posterior to the anus

Front 38

protostome

Back 38

A major division of the animal kingdom in which the blastospore develops into the mouth, and the anus forms secondarily; includes the annelids, arthropods, and mollusks.

Front 39

pseudocoelomate

Back 39

An animal having a pseudocoelem which is a body cavity between the mesoderm and endoderm; derived from the blastocoel.

Front 40

radula

Back 40

A rasp like structure in the digestive tract of chitons, snails, squids, and certain other mollusks.

Front 41

setae

Back 41

Bristle like structures that aid in annelid locomotion.

Front 42

spicule

Back 42

Secreted by amoeboid cells in the sponge; slender skeleton spikes; supports the mesohyl.

Front 43

spongocoel

Back 43

Located in a sponge; water enters through the ostia then passes through the spongocoel which is a central cavity(not a digestive cavity) and lows out through the osculum.

Front 44

asymmetrical

Back 44

Have no symmetry; sponges are asymmetrical.

Front 45

radially symmetrical

Back 45

A body plan in which any section through the mouth and down the length of the body divides the body into similar halves. Jellyfish and other cnidarians have radial symmetry.

Front 46

bilaterally symmetrical

Back 46

A body shape with right and left halves that are approximately mirror images of each other.

Front 47

test

Back 47

A shell.

Front 48

true coelomate

Back 48

Animal whose coelom is completely lined with mesoderm.

Front 49

tube foot

Back 49

Structures characteristic of echinoderms; functions in locomotion and feeding.

Front 50

vertebral column

Back 50

The vertebrates are distinguished from other chordates in having a backbone called the vertebral column, that forms the skeletal axis of the body. This flexible support develops around the notochord, and in most species it largely replaces the notochord during embryonic development. The vertebral column consists of cartilaginous or bony segments called vertebrae.

Front 51

visceral mass (of mollusk)

Back 51

The concentration of body organs(viscera) located above the foot in mollusks.

Front 52

water vascular system

Back 52

Unique hydraulic system of echinoderms; functions in locomotion and feeding.