Porifera Flashcards
What are Porifera known as? What does this mean?
Cellular grade organization = no true tissue
What symmetry are Porifera?
Asymmetrical or radial symmetry
What usually are Porifera cells? What does this mean?
Totipotent = immature or stem cell which give rise to other types of cells
What cells do Porifera have? 2 names
Choanocytes = collar cells
Explain the feeding habits between adults and larvae Porifera
Adults = sessile suspension feeders Larvae = mobile
Explain the outer and inner layers of the Porifera
Both lack basement membrane
Explain the middle layer of Porifera
Mesohyl = is variable but always has motile cells and some skeletal material
What are the 2 types of skeletal material in the middle layer of Porifera?
1- calcium carbonate
2- silicon dioxide and/or collagen fibers
Describe how water moves through a Porifera
Water moves through epidermis into spongocoel, passes over collar cells/choanocytes and out through osculum
What are archaeocyte cells of Porifera?
Wandering amoeboid cells that differentiate into specialize cells when necessary
What are the 2 types of cells that archaeocyte can differentiate into?
1- sclerocyte cells = spicules (calcareous or siliceous)
2- spongocytes cells = spongin (collagenous protein)
What other cells do archaeocytes develop into?
Give rise to sperm and egg cells
Explain the sponge structure of a Porifera
3 levels of increased complexity occur through high degree of everting of the choanocyte layer away from the spongocoel
What are the 3 levels of the sponge structure of a Porifera?
1- asconoid
2- syconoid
3- leuconoid (most sponges)
What is an example of a sponge that is 1 of the 3 levels for it’s sponge structure? What is special about it?
Bath sponge = leuconoid
Skeleton is made of a soft protein called spongi rather than calcium