invertebrates and vertebrates

What are the key features of Agnathans (jawless fishes)?

Skeletons made of cartilage, no jaws, notochord present, gill slits, no paired appendages. Examples: Lamprey, eel.

What are the key features of Chondrichthyes (cartilaginous fishes)?

Skeletons made of cartilage, jaws, vertebrae, gill slits, paired appendages, thick fins, internal fertilization. Examples: Sharks.

What are the key features of Actinopterygii (bony fishes)?

Bony skeletons, fins with stiff rays, external fertilization. Examples: Salmon, trout, perch.

What are the key features of Amphibia (amphibians)?

Aquatic larvae (tadpoles), adults with four limbs (tetrapods), breathe through lungs and/or skin, external fertilization. Examples: Frogs, salamanders.

What are the key features of Reptilia (reptiles)?

Tetrapods with dry, scaly skin, breathe with lungs, internal fertilization, cold-blooded. Examples: Lizards, snakes, turtles.

What are the key features of Aves (birds)?

Forelimbs modified as wings, capable of flight, feathers, warm-blooded, internal fertilization. Examples: Robin.

What are the key features of Mammalia (mammals)?

Tetrapods with hair, nurse young with milk, warm-blooded, large brains, internal fertilization. Examples: Cheetah, humans.

What are the key features of Arthropoda (arthropods)?

Segmented bodies, jointed appendages, complex sensory system with antennae, hard outer skeleton with chitin. Examples: Insects, spiders.

What are the key features of Nematoda (roundworms)?

Unsegmented, cylindrical bodies, complete digestive tracts, parasites. Examples: Dog heartworm.

What are the key features of Annelida (segmented worms)?

Bodies and most internal organs are segmented, complete digestive systems, gas exchange occurs through skin and gills. Examples: Earthworms.

What are the key features of Mollusca (mollusks)?

Three main unsegmented body parts: foot, visceral mass, mantle. Complete digestive, circulatory systems, gills for gas exchange. Examples: Snail, clams, mussels.

What are the key features of Rotifera (rotifers)?

Small aquatic animals, use cilia to direct food into their mouths, no respiratory or circulatory system. Examples: Rotifers.

What are the key features of Platyhelminthes (flatworms)?

Flattened, unsegmented worms, some are parasitic, contain digestive cavity with a single opening, no circulatory or respiratory system. Examples: Tapeworm.