46 terms

Ch 29 - Introduction to Invertebrates

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acoelomate
A solid-bodied animal lacking a cavity between the gut and outer body wall.
Animalia
Kingdom of the most complex organisms; multi-cellular, heterotrophic, lack rigid cell walls, mobile, tissues in internal organs, sensory organs, nervous system
asymmetrical
not being the same on both sides.
bilateral symmetry
body plan in which only a single, imaginary line can divide the body into two equal halves; characteristic of worms, arthropods, and chordates
cephalization
the concentration of nerve tissue and sensory organs at the anterior end of an organism
cestode
ribbon-like flatworms that are parasitic in the intestines of humans and other vertebrates
cnidarian
radially symmetrical animals having saclike bodies with only one opening and tentacles with stinging structures / uses stinging cells to capture food and defend itself
coelom
a cavity in the mesoderm of an embryo that gives rise in humans to the pleural cavity and pericardial cavity and peritoneal cavity
coelomate
An animal that possesses a true coelom (a body cavity lined by tissue completely derived from mesoderm).
comb jelly
biradially symmetrical hermaphroditic solitary marine animals resembling jellyfishes having for locomotion eight rows of cilia arranged like teeth in a comb, Member of phylum Ctenophora; free-swimming marine invertebrates.
cyst
a small anatomically normal sac or bladderlike structure (especially one containing fluid)
dueterostome
An evolutionary line that are characterized by radial, indeterminate cleavage and development of the anus from the blastopore
dimorphic
undergoing two different adult morphologies, has both sessile (polyps) and motile (medusa) stages
elephantiasis
a condition in which the limbs become extremely swollen and the skin hardens and thickens, happens when a large amount of filarial worms block lymphatic vessels
flatworms
A group of often parasitical worms that have bilateral symmetry, a one opening digestive system, and the beginnings of a brain; tapeworm, Phylum Platyhelminthes
gastrovascular cavity
digestive chamber with a single opening, in which cnidarians, flatworms, and echinoderms digest food
heartworm disease
disease of dogs, cats, ferrets. mosquitoes are key to disease transmission. affects all areas of the US
hermaphroditic
possessing both the male and the female reproductive organs
hydra
small tubular solitary freshwater hydrozoan polyp
invertebrate
any animal lacking a backbone or notochord
medusa
one of two forms that coelenterates take: is the free-swimming sexual stage in the life cycle of a coelenterate and has a gelatinous umbrella-shaped body and tentacles
mesoglea
in cnidarians, the jellylike material located between the ectoderm and the endoderm
nematocyst
In a cnidocyte of a cnidarian, a specialized capsule-like organelle containing a coiled thread that when discharged can penetrate the body wall of the prey.
nerve net
in cnidarians, a network of nerve cells that lacks a central control; impulses pass in any or all directions to produce a generalized response
Obelia
a Hydrozoan, we looked at preserved colonies, includes both polyp and medusa stages on the colony (nutritive polyps called hydranths and reproductive polyps called gonangia
polyp
one of two forms that coelenterates take e.g. a hydra or coral: usually sedentary and has a hollow cylindrical body usually with a ring of tentacles around the mouth
proglottid
Detachable section of a tapeworm that contains muscles, nerves, flame cells, and reproductive organs
protostome
Animal whose mouth is formed from its blastopore
pseudocoelomate
An animal whose body cavity is lined by tissue derived from mesoderm and endoderm.
radial symmetry
body plan in which body parts repeat around the center of the body; characteristic of sea anemones and sea stars
ribbon worm
soft unsegmented marine worms that have a threadlike proboscis and the ability to stretch and contract
rotifer
a member of the phylum which consists of small, aquatic invertebrates whose ring of cilia around the mouth makes the animal look like a spinning wheel
roundworm
member of a group of cylindrical invertebrates with pointed heads and tapered tails
schistosomiasis
a disease that is caused by a parasitic blood fluke and that affects the skin, intestines, liver, vascular system, or other organs
scolex
knob-like, anterior end of tapeworm, having hooks and suckers that attach to the host's intestinal lining
segmentation
Division of an animal body along its length into a series of repeated parts
sessile
describes an organism that remains attached to a surface for its entire life and does not move
sessile filter feeder
animal that stays in one place and consumes small food particles from the water
spicule
needle of silica or calcium carbonate in the skeleton of some sponges
sponge
primitive multicellular marine animal whose porous body is supported by a fibrous skeletal framework
spongin
a fibrous protein that contains sulfur and composes the fibers of the skeleton of some sponges
trematode
parasitic flatworms having external suckers for attaching to a host
trichinosis
disease causd by roundworms resulted in eating uncooked meat
tube-within-a-tube body plan
body with a digestive tract that has both a mouth and an anus
turbellarian
flatworm with three tissue layers, acoelomate, no unique characters, inhabit freshwater streams and ponds, oceans and moist terrestrial environments
vertebrate
animals having a bony or cartilaginous skeleton with a segmented spinal column and a large brain enclosed in a skull or cranium