Porifera and Cnidaria Flashcards
Body plan
AKA bauplan
The blueprint for the way the body of an organism is laid out
Major groups are distinguished by their unique body plan
Body plans differ in
Complexity of organization
Body symmetry
Developmental patterns
There are 32 different body plans in the animal phyla
Animal body plans differ in the grade of organization, in body symmetry, in the number of embryonic germ layers, and in the number of body cavities
Bilateral vs Radial symmetry
Bilateral - right and left sides (midsaggital division produces two mirror image halves)
Radial symmetry is where an object can be divided into equal halves by multiple planes
Phylum Porifera
Water enters body through pores, suspension feeders (they filter suspended particles from surrounding water)
How many species in Porifera?
Area they live?
Size?
Order?
15,000+
All aquatic, mostly marine
vary from a few mm to more than 2m
Cellular grade of organization
Extracellular matrix in a sponge is called…
Mesohyl
Sponges are _ symmetrical
Where do they live?
Asymmetrical or radial
They are sessile and attach to some sort of substrate, but the larva stage is free-swimming
They rely on ___ digestion
Sponges don’t gastrulate, so they have no gut and rely on purely intracellular digestion
Sponges pump water to obtain ___ and ___
Dermal ostia
Spongocoel
Osculum
oxygen and nutrients
Dermal ostia : incurrent pores
Spongocoel: Large internal cavity
Osculum : single large opening
Choanocytes do what? How do they accomplish this?
Pinocytosis?
Provide the force for driving water through the system
Beating of the flagellum draws water through the collar, where food is trapped on microvilli
Pinocytosis is the process of endocytosis done when the cell takes in fluid and dissolved small molecules, such as proteins
Pinacocytes
Phagocytize food particles at the sponge surface
Archaeocyte
Archaeocytes perform the intracellular digestion by pumping digestive enzymes into the food vacuole and extracting the nutrients, then ridding of the waste via exocytosis
Three types of sponge organization
Asconoid, simple
Syconoid, more complex
Leuconoid, most efficient and grows the largest
These do not define taxonomic groups
Sponge skeleton
Composed of…
Two types of spicules
Can be fibrous or rigid
Fibrous: Composed of collagen fibers in the extracellular matrix and spongin (a modified form of collagen in sponges)
Rigid: Composed of spicules, crystals that are either calcareous (CaCO3) or Siliceous (SiO2)
Three types of cells making spicules
Scleroblasts, calcoblasts, silicoblasts
Classification of sponges is based on…
Spicule form and Chemical composition
3 types, asconoid, syconoid, leuconoid
monoecious
Dioecious
Single sex in one organism
Two sexes in one organism
Phenotypic plasticity … makes classifying sponges hard
the ability of individual genotypes to produce different phenotypes when exposed to different environmental conditions
This is because the same genotype can be pressured differently and display morphologies different from its genetically identical neighbor
Harp sponge
Predacious sponge
Cnidaria
How many species?
90,000
Entirely aquatic, mostly marine
Cells are organized into tissues
Diploblastic
Radially symmetrical around a longitudinal axis
GV cavity (incomplete gut)
Tentacles
Nerve Net
Mouth end is…
Opposite end is…
oral
Aboral
Two germ lays give rise to…
Ectoderm and Endoderm give rise to epidermis, mesoglea, and gastrodermis
mesoglea is risen from some combination of ectoderm and endoderm
Gastrovascular cavity
Single opening that serves as mouth and anus
Serves in extracellular and intracellular digestion
Cnidocyte
Contain a nematocyst, which is concealed by an operculum
Describe cnidocyte mechanism
Are they reusable?
Operculum opens and the filament comes shooting out at high speed, turning inside out and exposes the barb with venom to a prey item
They are not reusable and become reabsorbed after use, then replaced with new ones
Cnidocytes are considered ___ predators
passive predators