Exam 2 Study Guide (Revised) Flashcards
what is the cell type that secretes skeletal elements of the sponge?
amoeboid; called sclerocyte
which class of platyhelminthes is not parasitic?
turbellaria
parthenogenesis is the laying of ____ eggs
unfertilized
what kind of cells are located between the outer epidermis and digestive tract?
parenchymal cells
sponges from the class Homoscleromorpha have:
a true basement membrane
adherens cell junctions
a pinacoderm which is true tissue layer
all of the above
all of the above
all of the following are characteristic members of the phylum Porifera except which?
asymmetrical
three main cell types
central cavity, or a series of branching chambers, through which water circulates during filter feeding
diploblastic tissue organization
diploblastic tissue organization
all of the following are characteristic of members of the phylum Cnidaria except which?
radial or modified biradial symmetry
gelatinous mesoglea located between epidermal and gastrodermal tissue layers
triploblastic tissue
cnidocytes used in defense, feeding, and attachment
triploblastic tissue
the largest and most prominent stage in the life cycle of most members of the class Scyphozoa is the
medusa
planula
polyp
ephyra
medusa
the hydranth (gastrozoid) is the reproductive polyp in the Obelia life cycle
True or False
false
some anthozoans live in a mutualistic relationship with protists called zooxanthellae and are largely responsible for the formation of coral reefs
true or false
true
cnidocytes produce nematocysts that are discharged on stimulation of a cnidocil. cnidocytes are produced only in members of the phylum Cnidaria.
true or false
true
in most Porifera, the zygote develops into planktonic larva
true or false
false
Cells are never present in the mesoglea of cnidarians.
a.) True
b.) False
b.) False
In an ascon sponge, choanocytes _________________________.
a.) line radial canals that branch off the spongocoel
b.) line the spongocoel directly
c.) are found in flagellated chambers
d.) line incurrent canals
b.) line the spongocoel directly
Which of the following cell types is involved with creating water currents during filter feeding of a sponge?
a.) pinacocytes
b.) choanocytes
c.) porocytes
d.) archaeocytes
b.) choanocytes
The leucon body form is seen in the Class ____________________.
a.) Demospongiae
b.) Calcarea
c.) Hexactinellida
d.) all of the above
e.) none of the above
d.) all of the above
Gemmules are resistant capsules filled with pinacocyte cells.
a.) True
b.) False
b.) False
The soft corals have ____________ pinnate tentacles.
a.) 6
b.) 2
c.) 8
d.) 4
c.) 8
Acoelomates lack a body cavity because the
__________ cells completely fill the area
between the outer epidermis and digestive
tract
parenchymal
Cell types of Phylum Porifera
- Choanocytes
- Archaeocytes
- Pinacocytes
The sessile, tubular form of a cnidarian with a mouth and tentacles at one end and a basal disk at the other
Polyp
Cnidarian; colonial animal composed of different polyps that function together as a single organism; e.g. Obelia and Physalia
hydroid
A cnidarian body plan characterized by a bowl shape and adapted for a free-swimming life.
Medusa
Digestive chamber with a single opening, in which cnidarians, flatworms, and echinoderms digest food
gastrovascular cavity
a structure at the aboral end of a polyp used for attachment
pedal disc
-Type of cells are responsible for movement in Hydra
-form most of epidermis that cover organism and function in muscle contraction
epitheliomuscular
in cnidarians, the layer of cells surrounding the digestive tract
Gastrodermis
-in cnidarians, the jellylike material located between the ectoderm and the endoderm
-are gelatinous (at least 95% water) with epidermal and gastrodermal cells sending processes into it
Mesoglea
Special stinging structures on cnidarians that look like small harpoons.
Cnidocytes
In cnidarians, a stinging cell that is used to inject a toxin into prey
nematocyst
In aquatic osteichthyans, a protective bony flap that covers and protects the gills.
operculum
An organelle characteristic of the cnidaria that is used in defense, food gathering, and attachment.
cnida
Free-living forms
Parasitic forms
Leaf-like body
Length varies
Ribbon-like body
which phylum?
Phylum Platyhelminthes.
which class?
Most are free-living.
Their gut can be simple, branched, or absent.
They can be up to 50 cm long
turbellarians
monoecious means
both male and female sex cells in one body
zygote is retained within parent and provided with nourishment until it is released as ciliated larva; most sponges are this
viviparous
sponges release both sperm and oocytes into water for external fertilization
oviparous
The free-swimming larva of most sponges is a solid-bodied ____
parenchymula
which class of porifera is defined by:
Calcareous sponges with spicules
of calcium carbonate
– Spicules are straight (monaxons)
or have three or four rays
– Most are small with tubular or
vase shapes
– Many are drab in color, but some
are bright yellow, green, red, or
lavender
– Leucosolenia (Scypha) and Sycon
(Grantia) are marine shallow-
water
– Asconoid, syconoid and leuconoid body forms
class calcarea
which class of porifera is defined by:
Glass sponges with six-rayed spicules of
silica bound together to form network
– Deep-sea; vase or funnel shaped bodies
attached by stalks of root spicules onto the
substrate (radial symmetry in some)
– Have syncytial cell structure
class hexactinellida
which class of porifera is defined by:
Contains 95% of living sponge species include most large sponges
– Spicules are siliceous but not six rayed and may be absent or bound together by spongin
– Leuconoid body form for all species
– All marine except for Spongillidae, the freshwater sponges
– Marine demosponges are highly varied in color and shape, with some growing to several meters in diameter.
class demospongiae
which class of porifera is defined by:
-Mostly marine with a variety of colors but live in cryptic habitats
– Generally found near shore but
have deep water forms
– true
basement membrane
(extracellular matrix; ECM) under pinacoderm
– Also have adherens cell
junctions that form true tissues unlike other sponges
– Divided into two clades based
on absence or presence of
spicules
class homoschleromorpha
what trait of sponges is homologous to other animals?
proteins for cell adhesion and cell-signaling
are cnidarians typically sessile (free-floating)
yes
cnidarians start with zygotes developing into _____, which settles on hard substrate and metamorphoses into a polyp
planula
