Chapter 8-Porifera and Cnidaria Flashcards
What are the simplest forms of metazoans?
Porifera and Cnidaria
What type of animals are in the Phylum Porifera?
sponges
T/F Spongs are the simplest and most inanimate of all metazoans.
True
What separates sponges form all other animals?
lack of defined body symmetry and lack of tissues such as muscles and nerves
What does a sponge’s simple design accomplish?
primary functions of feeding, reproduction, and adaptive responses to the environment
Do sponges exhibit a cellular level or organization?
yes
What types of animals are in the Phylum Cnidaria?
hydras, jellyfish, corals and sea anemones
What type of organization do animals in Phylum Cnidaria exhibit?
tissue-level
What does tissue-level organization mean?
have muscles and nerves yet lack organs
What are 2 features unique to cnidarian?
radial symmetry and diploblastic
What does diploblastic mean?
two germ layers, ectoderm and endoderm, produced during embryonic development
What does triploblastic mean?
animals with 3 germ layers produced in embryonic development
Where do sponges primarily live?
marine environments, 150 species found in freshwater
How are sponges sessile organism?
attach themselves to rocks and other substrates with their sac-like body supported by water
What kind of support do sponges exhibit?
skeleton made up of inorganic spicules or interconnecting collagen fibers known as spongin
What are the flagellated cells called that line the chambers in sponges?
choanocytes
What do choanocytes do?
circulate water and filter microscopically small food particles
What is remarkable about the cell of a sponge?
plastic; individual cell types can differentiate to an amoeboid form and then redifferentiate into other cel types
T/F Single sponge cells can be the basis for entire colonies.
True
What are the two ends of the sac-like body of sponges called and used for?
basal end for attachment and upper end is an opening called an osculum
What lines the osculum?
long spicules
What is the spongocoel?
opening which runs the entire length down the center of the sponge
What are the pores called that allow water to enter sponge?
dermal ostia
What are the incurrent canals?
water enters through dermal ostia
What is the radial canal?
adjacent to incurrent canals separated by a layer of cells
What are porocytes?
special cells that allow water to pass through the radial canal
What canal do choanocytes line?
radial canal
What do the flagella do?
produce water currents that bring in food particles and oxygen; food particles are digested in food vacuoles