Animal Origins Flashcards
All members of the kingdom Animalia are believed to have evolved from a ______________ ancestor
common flagellated protist
The ____________ made possible the complex, multicellular body plan of animals
specialization of cells
Animals obtain their food—complex organic molecules—by _____________ of energy
active expenditure
______________,____________, & _____________ support similar animal phylogenies
Morphological, developmental, and molecular data
An ______________ is correlated with its ability to move
animal’s body cavity
Based on this, animals are classified as ____________ or ____________
acoelomates or coelomates
what is Acoelomate?
no body cavity
what is Pseudocoelomate?
cavity with muscle (mesoderm) only on outside
what is Coelomate?
cavity lined with peritoneum (mesoderm)
what is a gut?
digestive tract
What are the 2 major bilateral animal lineages?
protostomes and deuterostomes
Most animals have _________ or __________ symmetry
radial or bilateral
Radially symmetrical animals move ____________
slowly, if at all
Those with bilateral symmetry have _________, __________ concentrated at one end, and _____________
more rapid movements; neural tissue; sensory organs
What is the sponges phylum?
porifera
Sponges are simple animals that lack _________ and _________, but have several __________.
cell layers; body symmetry; cell types
Sponges feed via __________
choanocytes
What is choanocytes?
feeding cells that filter out small organisms and nutrients
In a sponge, what is Spicules?
skeletal elements
In a sponge, what are the pores called?
Pores called ostia
In a sponge, what is and what does the osculum do?
Osculum: large opening where water exits
What phylum are the jellyfish in?
Cnidarians
jellyfish are________ symmetrical
radially
How many cell layers do jellyfish have?
two cell layers
In jellyfish, what are the sting cells called and what do they do?
nematocyte; studded tentacles to capture prey larger and more complex than themselves
What kind of gut do jellyfish have?
Incomplete gut
What are the 2 stages of jellyfish and what do they do?
Polyp - where the jellyfish is born at
Medusa - the jellyfish itself
What are the different Cnidarian classes?
Class Hydrozoa
Class Scyphozoa
Class Anthozoa
Class Cubozoa
What are some examples of Hydrozoa?
freshwater Hydra and marine Portugese Man-of-War
What are some examples of Scyphozoa?
marine; includes jellyfish
What are some examples of Anthozoa?
marine; includes most corals and sea anemones
What are some examples of Cubozoa?
marine box jellies, sea wasps
Common ancestors of bilateral animals were probably simple, bilaterally symmetrical animals composed of ______________
flattened masses of cells
When did the Protostomes and Deuterostomes spilt?
Split during Cambrian period
Protostomes have a ___________ system, __________ cords, and larvae with __________ cilia
ventral nervous; paired nerve; compound
Deuterostomes have a ___________ system and larvae with _________ cilia
dorsal nervous; single
Protostomes split into two major clades and what are they?
lophotrochozoans and ecdysozoans
Some Lophotrochozoans have lophophore, what is that?
special feeding structure of ciliated tentacles that rings mouth; suspension feeding
Some Lophotrochozoans have a special larval stage called?
trochophore
Growth of lophotrochozoans is ________
incremental (do not molt)
Lophotrochozoans: Phylum ________ (Starts with a R)
Rotifera
Rotifers
No larger than many ciliated __________
highly developed ______________
protists; internal organs
Rotifer have what type of gut?
Complete gut
Lophotrochozoans: Phylum ______________ (Starts with a P)
Platyhelminthes
Platyhelminthes are what type of worm?
Flat worms
Platyhelminthes have ____ body cavity
no
Platyhelminthes have ____________ for oxygen transport
no organs
Platyhelminthes have a __________ gut
incomplete
How do Platyhelminthes move?
By cilia
Many species of Platyhelminthes are _________
parasitic
What are examples of Platyhelminthes
Chinese liver fluke and tapeworm
With in Protostomes, members of several phyla have _______________ forms
wormlike body
Phylum __________ have a diverse group of segmented worms that live in marine, freshwater, and terrestrial environments
Annelida
What are the 3 classes of phylum Annelida?
Class Oligochaeta
Class Polychaeta
Class Hirudinea
Class Oligochaeta: ________________ soil; ___________
freshwater or moist; earthworms
Class Polychaeta: _________ with fleshy __________ that extend from body __________
marine worms; parapodia; segments
Class Hirudinea: free-living or parasitic ___________
leeches
Phylum _________
evolved from _______ ancestors
Mollusca; segmented
What are the 3 basic components of a mollusca?
foot, mantle, and visceral mass
In Mollusc, Many species have a radula. What is a radula?
a rasping organ used in feeding
In mollusc, Most have shells secreted by the ________; some shells are reduced and/or internal
mantle
What are the classes of mollusc?
Chitons
Bivalves
Gastropods
Cephalopods
Chitons have __________ shells
segmented
Bivalves two _________
hinged
What are examples of Bivalves?
clams, oysters, scallops, mussels
What are examples of gastropods?
snails & slugs; whelks & conchs; marine nudibranchs (“sea slugs”)
What are examples of Cephalopods?
squid, octopus, cuttlefish, nautilus
