Evolution & Diversity II Flashcards
Animals are classified according to ____ and ____ characteristics, such as a ____ ____.
Animals are classified according to morphological and developmental characteristics, such as a body plan.
Asymmetry animal example
sponges
Bilateral Symmetry animal example
flatworms
humans
Radial symmetry phylum example
cnidarians
echinoderms
Types of body plans:
Diploblast
Triploblast
Diploblast
organs develop from two types of tissue during development
Triploblast
organs develop from three types of tissue during development
3 Types of triploblasts
Acoelomate
Eucoelomate
Pseudocoelomate
Acoelomate
an animal that has no internal, fluid-filled body cavity separating its body wall from its digestive tract
Acoelomate example
flatworms
Eucoelomate
an animal that has an internal, fluid-filled body cavity separating its body wall from its digestive tract.
Eucoelomate examples
Annelids
Chordates
Arthropods
Mollusks
Echinoderms
Pseudocoelomate
body fluids bathe the organs and receive nutrients and oxygen from the cavity fluid.
Pseudocoelomate example
Roundworms (nematodes)
Porifera characteristics
Spongocoel
Osculum
Mesohyl
Monoecious
Spongocoel
cylinder with a large central cavity
Osculum
opening through which water flows
Mesohyl
separates inner and outer cells. Fluid filled.
Within the mesohyl, amoebocytes secrete ____, which are…
spicules- protein fibers that give structure
Monoecious
Reproduce asexually by budding or fragmentation
gemmules
clusters of cells surrounded by a tough outer layer
Gemmules survive ____ ____ and can attach to a ____ and grow into a ____ ____.
Gemmules survive hostile environments and can attach to a substrate and grow into a new sponge.
example of Cnidaria
Jelly fish
Cnidaria characteristics
1) radial or biradial symmetry
2) reproduce both sexually and asexually
3) diploblastic
4) cnidocytes (“stinging cells”)
contain specialized organelle called the nematocysts
5) Alternate between two forms
Medusa- free floating (jelly fish)
Polyp – anemone
6) Three layers:
Epidermis – outer layer
Gastrodermis – inner layer
Mesoglea – jelly-like and non-living.
7) Perform extracellular digestion before nutrients move into the cells (glycolysis, krebs, electron transport chain).
cnidocytes (“____ ____”)
contain specialized organelle called the ____
(“stinging cells”)
contain specialized organelle called the nematocysts
two forms of cnidaria
Medusa- free floating (jelly fish)
Polyp – anemone
3 layers of Cnidaria
Epidermis – outer layer
Gastrodermis – inner layer
Mesoglea – jelly-like and non-living
4 classes of Cnidaria
Scyphozoa- the jellies and are motile and exclusively marine
Anthozoa- a sessile polyp body plan
Cubozoa - square in cross-section “box jellyfish.”
Hydrozoa- class have both polyp and medusa forms in their life cycle
example of Platyhelminthes
flatworm
Characteristics of Platyhelminthes
Free living or parasitic
Bilaterally symmetrical.
gas and nutrient exchange is dependent on diffusion and intercellular junctions.
Important classes include Trematoda (causes shistosomiasis and swimmers itch) and cestode (includes tape worms)
4 classes of Platyhelminthes
1) Turbellaria Pseudobiceros bedfordi / Planaria
2) Trematoda: includes about 20,000 species, most of which are parasitic with complex lifecycles
3) Cestoda includes segmented tapeworms such as Taenia saginata;
4) Monogenea - small parasitic flatworms
