BIO 469 Study Guide - Fall 2018, Comprehensive Midterm Notes - Triploblasty, Nervous System, Coelom
12 Oct 2018
School
Department
Course
Professor
BIO 469
MIDTERM EXAM
STUDY GUIDE
Fall 2018
9-4-17
● Sessile
● Ubiquitous in world's oceans
● Ecologically important
● Commercially important
● Tissue level of organization
Classification
● Phylum porifera “ pore bearing
○ Hexactinellida
○ Calcarea
■ Mostly found in caves, spicules made out of calcium carbonate or
aragonite
○ Homoscleromorpha
○ Demospongiae
■ Most abundant in Bermuda
Body Plan
● Choanocytes - collar cells
● Holes on top of sponges; Osculum
● Inflow of water through the Ostium
● Archeocyte; differentiates into whatever cell the sponge needs as well as produce
games
● Choanoderm; epithelioid
● Mesohyl (connective tissue)
● Pinacoderm (epithelioid)
Cell Types:
- Insert cell type slide
Choanocyte
● Flagella changes water pressure inside and outside of sponge and facilitate movement
(stays in place)
● Amebocyte: moves food from choanocyte to rest of the sponge (moves around)
Spicules
- Asconoid conditon
- Syconoid condition
- Leuconoid condition
Summary:
Sponges are colonial, sessile, and simple animals with pores, canals, and chambers through
which water flows. They feed on particles captured from the water
● Development
○ Cells indeterminate
● Cell Layers
○ Cellular grade of construction, no true tissue
● Symmetry
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○ Asymmetrical (unique to sponges)
● Type of gut
○ None (have digestive cells)
● Body cavity
○ None
● Segmentation
○ None
Physiology
● Nutrition: all filter feeders, some with algal symbionts
● Excretion/Osmoreg: Cellular (water current takes away wastes), no osmoreg
● Respiration: cellular
● Circulation: none ( nutrients may be transported from cell to cell via amebocytes)
● Skeleton: spicules and spongin
● Nervous system: No neurons but cell-to-cell communication, some sensory in larvae
● Locomotion: cilia or flagella only in larvae
Weird Feeding
● Asbestopluma spp.
○ Use hook shaped spicule to grab prey
○ Prey are gradually enveloped by migrating feeding cells that digest and absorb
Asexual Reproduction
● Budding of amebocytes and fragmentation
○ Fragmentation: rip sponge in half, the pieces will survive
- Most sponges are hermaphroditic but they produce sperm and eggs at different times
- Cross-fertilization is probably the norm
- Mature sperm and oocytes are released into the environment through aquiferous
systems
- Fertilization usually takes place in the water column or internally
- A planktonic larva forms
Broadcast spawning , brood spawning ( males release sperm and females keep eggs in
tissue)
Ecology
● Habitats
○ Sponges found worldwide
○ Hotspots of sponges are also hotspots of coral reefs
○ Caribbean and mediterranean
○ 4 main habitats; Coral reefs, Deep sea, seagrass meadows, and mangroves
■ Different adaptations and morphologies depending on location
● Predation
○ Starfish
■ Invert stomachs and digest sponge and reverse the process
○ Turtles
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Mostly found in caves, spicules made out of calcium carbonate or aragonite. Archeocyte; differentiates into whatever cell the sponge needs as well as produce games. Flagella changes water pressure inside and outside of sponge and facilitate movement (stays in place) Amebocyte: moves food from choanocyte to rest of the sponge (moves around) Sponges are colonial, sessile, and simple animals with pores, canals, and chambers through which water flows. They feed on particles captured from the water. Cellular grade of construction, no true tissue. Nutrition: all filter feeders, some with algal symbionts. Excretion/osmoreg: cellular (water current takes away wastes), no osmoreg. Circulation: none ( nutrients may be transported from cell to cell via amebocytes) Nervous system: no neurons but cell-to-cell communication, some sensory in larvae. Locomotion: cilia or flagella only in larvae. Use hook shaped spicule to grab prey. Prey are gradually enveloped by migrating feeding cells that digest and absorb. Fragmentation: rip sponge in half, the pieces will survive.
