Briefly describe each of the three different canal systems
Asconoid, Syconoid, Leuconoid
400
What are three types of characters or evidence that can be used to create a cladogram?
Comparative morphology, comparative biochemistry (amino acids and nucleotides), and comparative cytology (varaiation in numbers shapes and sizes of chromosomes)
400
Opposite of back region
Ventral
400
Describe two characteristics of a deuterostome and a protostome
If a sponge is put through a sieve and its cells are separated what can it do?
Reassemble itself
400
Explain how choanocytes work
flagellum pulls water through the collar and forces it out the top, particles too large to enter the collar become trapped in secreted mucus and slide down to the base where they are phagocytized by the cell body
500
What are three bits of information that can be drawn from a phylogentic tree?
-estimate ages of other branches on the tree
--common descent
--amount of adaptive evolutionary change
--evolutionary history
--homologies vs homoplasies
500
Radial symmetry occurs among which two phylums?
Cnidaria and echinodermata
500
Name two organ system derivatives of each of the three germ layers
Ectoderm - hair nails, skin, brain, mouth lining
Mesdoerm - circulatory system, skeletal muscle, bone and cartilage
Endoderm - liver pancreas, smooth muscle and connective tissue of digestive tract
500
What are five defining characteristics of sponges?
Multicellular, no true tissues, all aquatic, radial symmetry or none, choanocytes, made of collagen/spongin/spicules, No organs, all adults sessile, asexual or sexual reproduction
500
Describe class demospongiae
contain 95% of living sponge spieces, spicules or siliceous, all members are leuconoids and all are marine