Animal diversity Flashcards
bilateral symmetry
animal has a dorsal (top) and ventral (bottom side; left and right; anterior (head) and posterior (tail)
radial symmetry
any imaginary slice through the central axis divides the animal into mirror images
coelomate
body cavity completely lined on inner and outer layers by tissue derived from mesoderm
pseudocoelomate
nematodes; fully functional body cavity only partially lined by tissue derived from mesoderm
acoelomate
flatworms; lack a body cavity between the digestive tract and outer body wall
body cavity
fluid cushions organs and enables the internal organs to grow and move independently of outer body wall
protostome development
distinguished by spiral and determinate cleavage, schizocoelous, and mouth develops from blastopore
spiral cleavage
the planes of cell division are diagonal to the vertical axis of the embryo; often associated with determinate early fate of cells
radial cleavage
cleavage planes are either parallel or perpendicular to the vertical axis of the egg
deuterostome development
radial and indeterminate cleavage, enterocoelous, and anus develops from blastopore
schizocoelous development
in protostome development the coelom forms from splits in the mesoderm between the archenteron
enterocoelous development
in deuterostome development the coelom forms from mesodermal folding of archenteron
porifera
sponges are simple, sessile animals that lack true tissues
cnidaria
corals, jellies, and hydra; gastrovascular cavity with one opening
platyhelminthes
flatworms; bilateral symmetry and central nervous system, no body cavity or organs
rotifera
microscopic size, have alimentary canal (digestive tract)
spongocoel
water enters this central cavity through pores called porocytes and exits through the large osculum opening
mesohyl
the inner matrix of sponge between two layers of cells
amoebocyte
transport nutrients after phagocytosis from the feeding cell choanocytes to the sponge body
cnidocytes
cells that function in defense and capture of prey on cnidarian tentacles
polyps
stationary body form of cnidaria like hydra
medusa
floating body form of cnidarian like jellyfish
hydrozoans
polyp form is diploid and asexual; medusa form reproduces sexually
hydra
cnidaria found in fresh water and exist only in polyp form
scyphozoans
jellyfish; medusa is the predominant stage; some coastal have small polyp stage
anthozoans
coral and sea anemone; exist only as polyp
flaworms
platyhelminthe; tripoblastic development, acoelomates
planarian
ganglia with ventral nerve cords
rotifers
alimentary canal, pseudocoelom
parthenogenesis
some rotifer reproduce only females from unfertilized eggs
lophophores
true coelom; circular crown of ciliated tentacles surrounding mouth
molluscs
snails, oysters, squid; muscular foot, visceral mass, mantle
mollusc visceral mass
contains most of the internal organs
mollusc mantle
tissue that drapes over the visceral mass and could secrete a shell
gastropod torsion
visceral mass rotates and animals anus wind up above head
cephalopod
active predators of octopus, squid
annelid
earthworm; cerebral ganglia, closed circulatory system
nematodes
alimentary canal, lack circulatory system, pseudocoelom
arthropods
crustaceans, spiders, insects; segmented coelomates, exoskeleton, jointed appendages
arthropod cuticle
exoskeleton constructed from layers of protein and polysaccharide chitin
open circulatory system
many molluscs and arthropods, fluid called hemolymph pumped through heart through arteries to sinuses surrounding organs
decapods
curstacean arthropods of lobster, shrimp
deuterostomes
echinoderm (sea star) and chordates
chordates
notochord and dorsal, hollow nerve cord
tunicates
posses a notochord, stationary
lancelets
possess a brain
hagfish
posses a head; craniates with a neural crest
lampreys
vertebral column
mineralized skeleton
sharks, rays
lung derivatives
ray finned fishes
lobed fins
actinistia
legs
amphibians-frogs, salamander
amniotic egg
reptiles-turtle, snake, crocodile, birds
milk
mammals
gnathosomes
jaws; placoderms
tetrapods
gnathostomes that have limbs and feet
archosaurs
diapsid lineage that produced crocodiles, birds, and dinosaurs
monotremes
mammals that lay eggs, have hair and produce milk secreted through glands
marsupials
give birth to live young with placenta and grows up in outer pouch very young
eutherian
commonly called placental mammals because placentas are more complex than marsupials
