Porfiera Flashcards
Sponge bodies do not have organs, instead they have masses of cells supported by
spicules and spongin
Porifera have an extensive fossil record that extends back to the ________ era.
Cambrian
Of the 5,000 species of sponges, only ________ live in freshwater; the rest are marine.
150
The pores in the surface of a sponge that pass incoming water to the body are called __________ and the opening by which water passes out of the sponge is called the __________.
Ostia and osculum
The flagellated cells that line the canals of the sponge are called
choanocytes
The interior cavity of an asconoid sponge is called the
spongocoel
In a syconoid type of sponge, the choanocytes are located in the
radial canals
Of the three types of body or canal designs in sponges, which is the most complex, as it is composed of multiple flagellated chambers?
leuconoid
Of the following cell types found in sponges, which one covers the external surface?
pinacocytes
Of the following cell types found in sponges, which one is arranged in bands around the oscula?
myocytes
Of the following cell types found in sponges, which are tubular and pierce the body wall?
porocytes
Of the following cell types found in sponges, which ones move around in the mesohyl?
archaeocytes
Which of the following cell types is responsible for making spicules?
sclerocytes
Sponges are typically classified into _________ different classes.
3 or 4
The larval form that is characteristic of the Demospongiae is the
parenchymula
In a leuconoid sponge, the choanocytes are found in the
flagellated chambers
All mesozoans are small marine parasites living in invertebrates.
true
In sponges, food is digested in the spongocoel.
false
Sclerocytes secrete fibrillar spongin fibers.
false
When sponges reproduce asexually by internal buds, these are called gemmules
true
Sponge bodies are organized at the tissue level of structure.
false
The nervous system of the poriferans is a nerve net.
false
Sponges live attached to a substrate; this lifestyle is called sessile.
true
Around the osculum of a sponge are cells that aid in regulating the water flow; these cells are called myocytes.
true
The cells in the body wall of a sponge that pass water into the interior are called choanocytes.
false
The opening by which water passes out of a sponge body is called the dermal ostia.
false
The body design of a sponge that has many multiple flagellated chambers within the body wall is called leuconoid.
true
The channels that pass water from the outside of the sponge into the flagellated chambers are called the excurrent canals.
false
In addition to budding, sponges can reproduce asexually by a stage that is able to resist unfavorable conditions. This stage is called a gemmule.
true
In sponges, excretion and respiration is accomplished by diffusion, although contractile vacuoles occur in freshwater sponges.
true
Sclerocytes secrete spicules, spongocytes secrete spongin, and collencytes secrete collagen.
true
Most sponges are oviparous, with fertilized eggs exiting the body of the sponge through the osculum.
false
The collar of the collar cell is composed of microvilli.
true