Characteristics of Mammals and Amphibians

Mammals

• Warm-blooded (endothermic)
• Hair or fur present
• Three middle ear bones (ossicles)
• Mammary glands present for milk production
• Live birth (except for platypus and echidna)
• Brain development:
  • Large cerebral cortex
  • Neocortex divided into four lobes
• Examples: humans, lions, bears, whales, monkeys

Amphibians

• Cold-blooded (ectothermic)
• Moist, smooth skin
• Lay eggs in water
• Undergo metamorphosis from larva to adult
• Respire through skin and lungs
• Examples: frogs, toads, salamanders, newts

Reptiles

• Cold-blooded (ectothermic)
• Scaly skin
• Lay eggs on land
• Breathe air through lungs
• Heart with three or four chambers
• Examples: snakes, lizards, turtles, crocodiles, alligators

Birds

• Warm-blooded (endothermic)
• Feathers present
• Lay eggs on land
• Light skeleton with hollow bones
• Respiratory system adapted for flight
• Examples: sparrows, eagles, robins, penguins, ostriches

Invertebrates

• No backbone (vertebral column)
• Diverse group, including:
  • Insects (bees, wasps, butterflies)
  • Arachnids (spiders, scorpions)
  • Mollusks (squid, octopuses, clams)
  • Echinoderms (starfish, sea urchins)
  • Worms (flatworms, roundworms)
  • Crustaceans (crabs, lobsters, shrimp)
• Examples: ants, beetles, flies, worms, jellyfish

Mammals

• Characterized by being warm-blooded (endothermic) and having hair or fur
• Possess three middle ear bones (ossicles) for hearing
• Mammary glands present for milk production to nourish young
• Give birth to live young, except for platypus and echidna
• Brain development features a large cerebral cortex and a neocortex divided into four lobes
• Examples include humans, lions, bears, whales, and monkeys

Amphibians

• Cold-blooded (ectothermic) and have moist, smooth skin
• Lay eggs in water and undergo metamorphosis from larva to adult
• Respire through skin and lungs
• Examples include frogs, toads, salamanders, and newts

Reptiles

• Cold-blooded (ectothermic) and have scaly skin
• Lay eggs on land and breathe air through lungs
• Heart features three or four chambers
• Examples include snakes, lizards, turtles, crocodiles, and alligators

Birds

• Warm-blooded (endothermic) and have feathers
• Lay eggs on land and have a light skeleton with hollow bones
• Respiratory system adapted for flight
• Examples include sparrows, eagles, robins, penguins, and ostriches

Invertebrates

• Diverse group characterized by the absence of a backbone (vertebral column)
• Includes insects, arachnids, mollusks, echinoderms, worms, and crustaceans
• Examples include ants, beetles, flies, worms, jellyfish, and various others