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27 terms

Modern Biology Chapter 33

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sponges
Aquatic, sessile invertebrates that have no true tissues or organs that make up the phylum Porifera.
sessile
Describes an organism that remains attached to a surface for its entire life and does not move.
choanocytes
Collar cells; Flagellate cells that line the cavities of a sponge and draw water into the sponge by beating their flagella.
ostium
A pore in the body wall of a sponge.
osculum
An opening at the top of the sponge; where water leaves in a sponge.
spongin
Tough, flexible protein fibers; what some sponge skeletons are made of.
spicules
Tiny, hard particles of calcium carbonate or silicon dioxide that are often shaped like spikes; what some sponge skeletons are made of.
filter feeding
A method of feeding in which an aquatic animal traps organic material that is floating in the surrounding water; how sponges feed.
amoebocytes
Cells which crawl about within the body wall of a sponge that distribute nutrients throughout the body.
gemmules
Asexually produced internal buds that some freshwater sponges create during poor conditions. Food-filled balls of amoebocytes surrounded by a protective coat made of organic material and spicules that can survive harsh conditions.
regeneration
The regrowth of missing cells, tissues, or organs.
hermaphrodites
Organisms that produce both eggs and sperm.
medusa
Bell-shaped body form of a cnidarian that is specialized for swimming.
polyp
Vase-shaped body form of a cnidarian that is specialized for a sessile existence.
epidermis
The outer cell layer of a cnidarian.
gastrodermis
The inner cell layer of a cnidarian.
mesoglea
A jellylike material between the epidermis and gastrodermis of a cnidarian.
gastrovascular cavity
The hollow gut in the center of the body of a cnidarian which has a single opening, or mouth.
tentacles
Numerous flexible extensions surrounding the mouth of a cnidarian.
cnidocytes
Specialized cells used for defense and capturing prey.
nematocyst
A cnidocyte organelle which has a long filament coiled up inside it.
nerve net
A diffuse web of interconnected nerve cells of a cnidarian.
planula
A ciliated larva that develops from the blastula of a scyphozoan.
coral reefs
Large, rocklike formations built up from anthozoan polyps.
colloblasts
Cells of ctenophores which secrete a sticky substance that binds to their prey.
apical organ
A sensory structure at one end of a ctenophore's body that enables ctenophores to sense their orientation in the water.
bioluminescence
The production of light by means of a chemical reaction.