1. Comparing Evolutionary Trends in Invertebrates and Vertebrates
(Chapters )

2. Body Symmetry Radial symmetry: extends from the center outwards
Bilateral symmetry: sides are like mirror images (left and right)

3. Nervous System (Response)
Cephalization: concentration of sense organs and nerve cells in front (top) of the body
Evolution from ganglia (simple) to brain (complex)

4. Body Cavity
coelom: area of body cavity between the body wall and the digestive cavity
Acoelomate: animal that lacks a body cavity
Ex: flatworm (planaria)
Pseudocoelomate: animal that has a partial body cavity
Ex: roundworm (earthworm)

5. Embryo Development Depends on what the blastopore develops into first…
Protostome: mouth develops first
Ex: invertebrates
Deuterostome: anus develops first
Ex: humans

6. Feeding and Digestion
Intracellular digestion: digestion occurs inside the cells
Ex: sponges
Extracellular digestion: digestion occurs outside the cells in the digestive tract
Ex: arthropods

7. Respiration (“Breathing”)
Gills: feathery structures that take in O2 from the water- usually close to the body surface
Ex: fish
Alveoli: tiny air sacs at the end of the bronchiole that increase surface area and act in gas exchange
Ex: humans

8. Vertebrate Introduction
Notochord: long supporting rod that runs below the nerve cord
Chordate: organism that has a dorsal nerve cord

9. Circulatory System Open system: blood is not always in vessels
Ex: insects, clams
Closed system: blood always in vessels
Ex: humans

10. Excretion Roles: control the output of waste products
Involved in water balance

11. Movement and Support
Hydrostatic skeleton: move with water-filled cavity and accessory muscles
Ex: jellyfish
Exoskeleton: external skeleton on outside of body
Ex: insects
Endoskeleton: internal skeleton on inside of body
Ex: kangaroo

12. Reproduction
External fertilization: eggs fertilized outside the body (ex: coral)
Internal fertilization: eggs fertilized inside the body (ex: humans)
Oviparous: eggs develop outside the mother (ex: snake)
Ovoviparous: embryo gets nutrients from the yolk of egg (ex: seahorses)
Viviparous: embryo gets nutrients from mom (ex: humans)

13. Regulating Body Temp.
Ectotherm: body temp determined by environment- organism must
Ex: lizards
Endotherm: body temp controlled internally
Ex: dogs

14. Reproductive Strategies
K selection: having only a few offspring but investing a lot of parental care into them
Ex: humans, gorillas
Occurs in crowded, competitive populations
r selection: having many offspring but investing very little parental care
Ex: carp fish
Occurs in populations that grow and change rapidly