Exam 2 Flashcards
Tissues
An organization of specialized cells
Germ Layers
Ectoderm, endoderm, mesoderm
Ectoderm
Epithelial tissue and nervous tissue
Mesoderm
Muscular, circulatory, skeletal
Endoderm
Gives rise to internal organs
Free Form Symmetry
No symmetry
Radial Symmetry
When a plane can be passed through a central axis and divide the organism into two equal halves
Bilateral Symmetry
When a plane can be passed one way through a central axis to divide the organism into two equal halves
Cephalization
The grouping of primary sensory organs at one end of the organism
Coelom
“Cavity”; A space between the gut and body wall used to house organs
Acoelomates
No body cavity; less complex
Pseudocolemates
Have a partially lined cavity
Coleomates
Have a fully lined body cavity
Segmentation
Similar repeated units; allows for an increase in size without the need for new DNA
Intercellular Digestion
Digestion within the cell
Gastrovascular Cavity
One opening, both mouth and anus
Complete Digestive Tract
Two openings, mouth separate from the anus
Invertebrates
Animals that lack a backbone
Vertebrates
Animals that have a backbone
Porifera
Sponges
Cnidaria
Jellyfish
Platyhelminthes
Flatworms
Annelida
Segmented worms
Nematoda
Round worms
Arthropoda
“jointed skeleton”
Deuterostomes
The first embryonic opening is the anus and the second becomes the mouth
Chordates have:
notochord, a dorsal nerve chord, pharyngeal gill slits, tail near anus
Invertebrate Chordates have:
Everything but the bony set of vertebrae
Tunicates
Sea squirts
Cephalochordates
Lancelets
Jawless Fish
Lampreys, hagfish
Chondrocytes
Sharks, skate, rays