Chapter 33: An Introduction To Invertebrates

Question 1

Filter Feeders

Answer 1

An animal that feeds by using a filtration mechanism to strain small organisms or food particles from its surroundings

Question 2

Spongocoel

Answer 2

The central cavity of a sponge

Question 3

Osculum

Answer 3

A large opening in a sponge that connects the spongocoel to the environment

Question 4

Choanocytes

Answer 4

A flagellated feeding cell found in sponges. Also called a collar cell, it has a collar like ring that traps food particles around the base of its flagellum

Question 5

Mesohyl

Answer 5

A gelatinous region between the two layers of cells in a sponge

Question 6

Amoebocyte

Answer 6

An amoeba-like cell that moves by pseudopodia and is found in most animals. Depending on the species, it may digest and distribute food, dispose of wastes, form skeletal fibers, fight infections, or change into other cell types.

Question 7

Hermaphrodites

Answer 7

An individual that functions as both male and female in sexual reproduction by producing both sperm and eggs

Question 8

gastrovascular cavity

Answer 8

A central cavity with a single opening in the body of certain animals, including cnidarians and flatworms, that function in both the digestion and distribution of nutrients

Question 9

Polyp

Answer 9

The sessile variant of the cnidarian body plan.

Alternate form is the Medusa

Question 10

Medusa

Answer 10

The floating, mouth-down form of the cnidarian body plan

The alternate form is the polyp

Question 11

Cnidocyte

Answer 11

A specialized cell unique to Cnidaria; contains a capsule-like organelle housing a coiled thread that, when discharged, explodes outwards and functions in prey capture or defense.

Question 12

nematocysts

Answer 12

In a cnidocyte of a cnidarian, a capsule-like organelle containing a coiled thread that when discharged can penetrate the body wall of the prey.

Question 13

Exoskeleton

Answer 13

A hard encasement on the surface of an animal, such as the shell of a mollusk or the cuticle of an arthropod, that provides protection and points of attachment for muscles

Question 14

Protonephridum

Answer 14

An excretory system, such as the flame bulb system of flatworms, consisting of a network of tubules lacking internal openings

Question 15

Planarian

Answer 15

A free-living flatworm found in ponds and streams

Question 16

Alimentary canal

Answer 16

A complete digestive tract, consisting of a tube between a mouth and an anus. Found in rotifers

Question 17

Parthogenesis

Answer 17

A form of asexual reproduction in which females produce offspring from unfertilized eggs

Question 18

Ectoproct

Answer 18

A sessile, colonial lophotrochozoan

Question 19

Brachiopod

Answer 19

A marine lophotrochozoan with a shell divided into coral and ventral halves; also called lamp shells

Question 20

Visceral Mass

Answer 20

One of the three main parts of a mollusk; the part containing most of the internal organs

Question 21

Mollusk Foot

Answer 21

One of the three main parts of a mollusk; A muscular structure usually used for movement

Question 22

Mantle

Answer 22

One of the three main parts of a mollusk; a fold of tissue that drapes over the visceral mass and may secrete a shell.

Question 23

Mantle cavity

Answer 23

An water-filled chamber that houses the gills, anus, and excretory pores of a mollusk

Question 24

Radula

Answer 24

A strap like scraping organ used by many mollusks during feeding

Question 25

Ammonite

Answer 25

A member of a group of shelled cephalopods that were important marine predators for hundreds of millions of years until their extinction at the end of the Cretaceous period

Question 26

Cuticle

Answer 26

Any of a variety of tough but flexible, non-mineral outer covering of an organism, or parts of an organism, which provide protection

Question 27

Molting

Answer 27

A process in ecdysozoans in which the exoskeleton sheds at intervals, allowing growth by the production of a larger exoskeleton.

Question 28

Arthropods

Answer 28

A segmented ecdysozoan with a hard exoskeleton and jointed appendages. Familiar examples include insects, spiders, milipedes, and crabs

Question 29

Open circulatory system

Answer 29

A circulatory system in which fluid called hemolymph bathes the tissues and organs directly and there is no distinction between circulating fluid and interstitial fluid

Question 30

Chelicerate

Answer 30

An arthropod that has chelicerae and a body divided into a cephalothorax and an abdomen.

Includes sea spiders Horshoe crabs, scorpions, ticks, and spiders.

Question 31

Myriapods

Answer 31

A terrestrial arthropod with many body segments and one or two pairs of legs per segment. Millipedes and centipedes are the two major groups of living myriapods.

Question 32

Pancrustacean

Answer 32

A member of a diverse arthropod clade that include lobsters, crabs and other crustaceans, as well as insects and their six-legged terrestrial relatives

Question 33

Chelicera

Answer 33

One of a pair of clade like feeding appendages characteristic of chelicerates

Question 34

Eurypterid

Answer 34

An extinct carnivorous chelicerate; also called a water scorpion

Question 35

Arachnid

Answer 35

A member of a subgroup of the major arthropod clade chelicerata. Arachnids have six pairs of appendages, including four pairs of walking legs, and include spiders, scorpions. Ticks, and mites.

Question 36

Book lung

Answer 36

An organ of gas exchange in spiders, consisting of stacked plates contained in an internal chamber

Question 37

Incomplete metamorphosis

Answer 37

A type of development in certain insects, such as grasshoppers in which the young resemble adults but are smaller and have different body proportions. The nymph goes through a series of molts, each time looking more like an adult, until it reaches full size

Question 38

Complete metamorphosis

Answer 38

The transformation of a larva into an adult that looks very different, and often functions very differently in its environment, than the larva

Question 39

Echinoderm

Answer 39

A slow-moving or sessile marine deuterostome with a water vascular system and, in larvae, bilateral symmetry. Includes sea stars, sea urchins, and sea cucumbers

Question 40

Water Vascular System

Answer 40

A network of hydraulic canals unique to echinoderms that branches into extensions called tube feet, which function in locomotion and feeding

Question 41

tube foot

Answer 41

One of numerous extensions of an echinoderm’s water vascular system.

They function in feeding and locomotion.