PAGE 1: Invertebrate Phyla at a Glance
| Phylum | Org Level | Germ | Coelom | Symm | Key Feature | Excretion | Circulation | Examples |
|---|---|---|---|---|---|---|---|---|
| Porifera | Cellular | — | — | Asym/Radial | Choanocytes, spicules | Diffusion | None | Sycon, Spongilla, Euspongia |
| Cnidaria | Tissue | Diplo | — | Radial | Cnidocytes, polyp+medusa | Diffusion | Gastrovascular | Hydra, Aurelia, Physalia |
| Ctenophora | Tissue | Diplo | — | Radial | Comb plates, bioluminescence | Diffusion | — | Pleurobrachia |
| Platyhelminthes | Organ | Triplo | Acoelomate | Bilateral | Flat, flame cells | Flame cells | None | Planaria, Taenia, Fasciola |
| Aschelminthes | Organ-sys | Triplo | Pseudo | Bilateral | Round, complete gut | Diffusion | None | Ascaris, Wuchereria |
| Annelida | Organ-sys | Triplo | True | Bilateral | Metameric, nephridia | Nephridia | Closed (most) | Nereis, Pheretima, Hirudinaria |
| Arthropoda | Organ-sys | Triplo | True | Bilateral | LARGEST, chitin, Jointed | Malpighian | Open | Apis, Bombyx, Limulus |
| Mollusca | Organ-sys | Triplo | True | Bilateral | 2nd LARGEST, mantle, radula | Metanephridia | Open (except Cephalopoda=Closed) | Pila, Pinctada, Octopus |
| Echinodermata | Organ-sys | Triplo | True | Radial adult/Bilateral larva | WVS, tube feet, | WVS diffusion | Haemal system | Asterias, Echinus, Antedon |
| Hemichordata | Organ-sys | Triplo | True | Bilateral | Stomochord, gill slits | — | — | Balanoglossus |
PAGE 2: Vertebrata Quick Reference
Heart Chambers:
- 2 chambers: Cyclostomata, Chondrichthyes, Osteichthyes (ALL fish)
- 3 chambers: Amphibia (undivided ventricle), Reptilia (incomplete septum)
- 4 chambers: Crocodilia (exception in Reptilia), Aves, Mammalia
Body Covering:
- Cyclostomata: Slimy skin (no scales)
- Chondrichthyes: Placoid scales
- Osteichthyes: Cycloid or Ctenoid scales
- Amphibia: Moist, glandular skin
- Reptilia: Dry, keratinized scales
- Aves: Feathers
- Mammalia: Hair/Fur
Temperature Regulation:
- Ectothermic: Cyclostomata, Chondrichthyes, Osteichthyes, Amphibia, Reptilia
- Endothermic: Aves, Mammalia
Respiration:
- Gills: All fish classes
- Lungs + Skin: Amphibia
- Lungs only: Reptilia, Mammalia
- Lungs + Air sacs: Aves (most efficient)
Key Exceptions (MUST KNOW for NEET):
- Crocodile → 4-chambered heart (reptile exception)
- Platypus + Echidna → oviparous mammals (monotremes)
- Cephalopoda (Octopus, Loligo, Sepia) → closed circulation (mollusc exception)
- Echinoderm larvae → bilateral (adult = radial)
- Limulus → Merostomata (NOT Crustacea despite name "king crab")
- Whale → Mammalia (NOT fish despite aquatic lifestyle)
- Penguin → Aves (NOT mammal despite cold environment and swimming)
- Hippocampus → Osteichthyes (NOT unusual — it IS a bony fish)
NEET Mnemonics (rapid fire):
- Phyla order: Poor Creatures Cry Poorly And Arrive At Many Exotic Homes Cheerfully
- Vertebrate classes: Cute Children Often Attack Roaming Angry Monsters
- Chordata features: No Dorsal Gills Post (Notochord, Dorsal cord, Gill slits, Post-anal tail)
- Fish = 2 chambers; Frogs/Reptiles = 3 chambers; Croc+Birds+Mammals = 4 chambers
- Only diploblastic: CN = Cnidaria + cteNophora