animals that do not have a backbone
invertebrates
multicelled heterotrophs that move about during part or all of the life cycle
animals
most animal cells are organized as ____, consisting of one or more cell types organized to perform a specific function
tissues
jellyfish and hydras have what type of symmetry?
radial symmetry
most animals have what symmetry?
bilateral symmetry
in most bilateral animals, nerve cells are concentrated at the head end
cephalization
most animals have this that opens at the body surface
gut
cavity lined by mesodermal tissue
coelom
cavity that is partially lined
pseudocoelom
have no body cavity
acoelomates
first opening in the embryo becomes the mouth, the second becomes the anus
protostomes
first opening in the embryo becomes the anus, second becomes the mouth
deuterostomes
collared flagellate" the modern protists most closely related to animals
choanoflagellates
sponges are part of which phylum?
phylum porifera
animals that attach to seafloor or other surfaces
sessile animals
animals that produce both eggs and sperm
hermaphrodites
zygote develops into a free-living, ciliated ____
larva
cnidarians are part of which phylum?
phylum cnidaria
a tentacle-ringed orifice opens into a _____ that functions in digestion and gas exchange
gastrovascular cavity
jellyfishes, are bell shaped and drift
medusa
sea anemones are tubular with one end usually attached to a surface
polyps
cells with stinging organelles, triggered by contact, used in feeding or defense
nematocysts
simple nervous system of interconnecting nerve cells extending through the tissues
nerve net
fluid-filled structure moved by contractile cells
hydrostatic skeleton
flatworms (phylum ____) have a three-layer embryo that developed into an adult with many organ systems but no coelom
platyhelminthes
annelids (phylum ___) are bilateral worms with a coelom, a closed circulatory system, and a segmented body; typically with chaetae (chitin reinforced bristles)
annelids
a band of cilia above its mouth forms during polychaete development
trochopore larva
mollusks are part of which phylum?
phylum mollusca
covers internal organs, secretes a shell
mantle
for respiration in aquatic species
gills
feed using a hard ____
radula
eight overlapping plates
chitons
snails, slugs, undergo torsion during development- the body mass twist, putting previously posterior parts, including the anus, up above the head, include the only terrestrial mollusks
gastropods
mussels, clams, oysters, hinged, two-part shell
bivalves
squids, octopuses, large, fast and smart, closed circulatory system
cephalopods
tiny bilateral animals, have a pseudocoelom, but are genetically closest to annelids and mollusks
rotifers
tiny bilateral animals, have a coelom and molt, and are probably relatives of roundworms and insects
tardigrades
roundworms (phylum ____) are unsegmented pseudocoelomate worms with a secreted cuticle that is molted
nematoda
are the most diverse animal phylum with more than a million species
phylum arthropoda
detect and touch chemicals
antennae
changing of body plans, example- caterpillar to butterfly
metamorphosis
have a three part body plant: the head has compound eyes, a pair of antennae, and specialized mouthparts, the thorax has three pairs of legs, some have wings, Malpighian tubes in the abdomen eliminate wastes and conserve water, a system of tracheal tubes
insects
have "spiny skins" embedded with interlocking spines and plates of calcium carbonate
echinoderms
they are brainless and have a unique ______ system for locomotion
water-vascular