Chapter 12: Exam Prep Flashcards
(18 cards)
Which one of the following statements regarding the origin of Metazoan’s has the most support?
The choanocytes shade features with the sponges, like having collars of microvilli surrounding a flagellum and being colonial. These shared features suggest a link to at least one metazoan lineage.
Which statement about adult sponges is false?
Their bodies are aggregations of one cell type
The order in which a drop of ink would pass by the structures in an ascot sponge is
Ostia-spongocoel-osculum
The simplest of canal systems is found in the
Asconoids
The most complex and the most common body form of sponges is found in the
Leucinoids
The extracellular matrix found in sponges is
Mesophyl or mesenchyme
Minute calcareous or siliceous, needle-like elements of the sponge body wall that provide skeletal support are called
Spicules
A sponge feeds by
Beating the flagella of collar cells to form a current; food is absorbed by collar cells
Cells that move about in the mesohyl, digest particles, and may specialize for other functions are the
Archaeocytes
Cells responsible for water flow and capture some particles are the
Choanocytes
If a sponge is fragmented and cells are dissociated from one another, the cells will
Reorganize their structure and function, and clumps of isolated cells will form a new sponge
Reproduction in at least some sponges is
All of the choices are correct. (Sexual with both male and female sex cells in one individual, asexual by gemmules, asexual by budding, asexual by fragmentation)
The largest impact that the loss of sponges would have on the environment would be
Loss of filtration
The tough protein fibers sometimes found in sponge skeletons are of a substance called
Spongin
The water outlet in sponges is known as a/an
Osculum
The flagellated cells embedded in the mesohyl of a sponge are called
Choanocytes
Internal buds of freshwater sponges that can withstand adverse conditions are
Gemmules
About 95% of the sponges belong to the class
Demospongiae
