Kingdom Animalia
Main

Eubacteria / Archaebacteria

Protista

Animalia

Fungi / Plantae

Viruses

Life Cycles

General Characteristics


  • all are multicellular
  • all are hetertrophs
  • most reproduce sexually
  • live in terrestrial and aquatic habitats

Characteristics Used to Classify Animals
  • body organisation - Does the animal have tissues, or tissues organismed into organs, or organ systems?
  • number of body layers - Does the animal have two or three layers?
  • body symmetry - Does the animal have radial or bilateral symmetry?
  • digestive tract or gut - Does the animal's gut have only one opening or does it have two openings: a mouth for food intake and an anus for expulsion of body waste
  • coelom or body cavity - Does the animal have a true body cavity, is it partially formed, or is it absent?

The Different Phyla

 

  • The Porifera, or sponges, are the simplest animals because they lack true tissues or organs.
  • Cnidaria possess two different body plans; polyp and medusa.
  • Some cnidarians show an alternation of sexual and asexual generations in their life cycle.


  • Platyhelminthes, or flatworms, have no coelom but they show bilateral symmetry, have mesoderm, true organs, and a primitive brain.
  • Nematodes, or roundworms, are more advanced because they have a pseudocoelom, a nervous system, and a complete digestive tract with a mouth and an anus.
  • Annelids are segmented worms and possess a true coelom.
  • Segmentation is an important evolutionary advantage because it allows for greater specialization.


  • All mollusks posses the same early development of the embryo, and have a larval stage before they mature into adults.
  • Adult mollusks vary greatly in their appearance but they share a common body plan.
  • All echinoderms are spiny-skinned animals that live in marine habitats.
  • Echinoderms posses a different type of early embryonic development from mollusks.  The adult forms possess radial symmetry with five similar body segments


  • The most diverse phylum of animals is Arthropoda, characterized by an exoskeleton and jointed appendages.
  • Arthropods include spiders, crustaceans, and insects, which play a vital role in the survival of all life on Earth.
  • In arthropods, some segments are fused and are specialized to perform certain functions for the whole animal.


  • Some cnidarians show an alternation .
  • Fish are the most numerous and widespread of the vertebrates

o       They are divided into jawless fish, cartilaginous fish, and bony fish

o       All fish have gills

  •  The earliest vertebrates were aquatic creatures that lacked jaws.

o       They have a notochord and a cartilaginous skeleton

o       The two groups of living jawless fish are lampreys and hagfish

  • Cartilaginous fish are jawed.

o       They have a skeleton made of cartilage

o       This group includes sharks, skates, and rays

  • All other jawed fish are bony fish

o       Bony fish are the most numerous

o       Bony fish have swim bladders, which help maintain buoyancy and allow the fish to float at different levels


  • The three orders are legless amphibians, the tailless amphibians, and the tailed amphibians.
  • Amphibians have two lives.

o       Reproducution occurs in water. They hatch fromeggs and, as tadpoles, are herbivores and exchange gases through gills.

o       When they become adults, they live on land, are carnivores, and exchange gases through their skin and lungs


  • Birds, like mammals, are warm-blooded; however, unlike mammals, all birds have feathers and lay eggs.
  • Birds display many characteristics for flight, such as feathers, hollow quills and bones, very efficient lungs with air sacs, an efficient heart, good vision, and rapid digestion.

 


  • Only monotremes, lay eggs.
  • Marsupials bear live young that complete their development in a pouch attached to the mother.
  • Most are placentals, all embryo development occurs within the uterus.
  • Typically mammals are warm-blooded, air breathing, and four legged.

o       They have hair, sweat glands, teeth fleshy lips, a diaphragm, a four chambered heart, and a middle ear.

o       Females have mammary glands, which secrete milk to nourish the young.

o       An endoskeleton means that mammals can grow continuously without moulting.

o       A complex brain and nervous system enables mammals to learn from experience and adapt readily to environmental changes.