CH+25+Notes



[|Animal Kingdom]
Characteristics
 * Multicellular
 * eukaryotic--have nucleus
 * specialized cells and tissues
 * heterotrophic-consumer
 * capable of movement/responding to stimuli

Body of Development Stages of Development
 * Blastula: a hollow ball of cells that develop from the zygote
 * Gastrula: two layered structrue that develops from the blastula and gives rise to germ cell layers


 * Endoderm: Inner most germ cell layers ex. digestive organs
 * Mesoderm: Middle germ cell layer ex. muscles and circulatory systems
 * Extoderm: Outer most germ cell layer, ex. skin, nervous system

Symmetry: Assymetry : irregularly shaped body (no symmetry) ex. sponges

Radial symmetry : Circular organization; appears to be the same from any angle--can be divided along any plane through a central axis into equal halves ex. starfish; hydra

Bilateral Symmetry : can be divided down length into right and left halves ex. humans

Body plans
 * Acdolomates: have no true body cavities
 * ex. flatworms
 * Pseudocoelomates: have body cavities that are only partially lined iwth mesoderm
 * ex. roundworms
 * Coelomates: have tru body cavities completely lined by mesoderm
 * ex. segmented worms, humans, insects, fishes

Classification
 * Invertebrates: animals without a backbone; many have an exoskeleton
 * ex. jellyfish, worms, clams, spiders, etc.
 * 95% of all animals are invertebrates, insects make up the largest of that; 8 phyla


 * Vertebrates: animals that have a backbone, an endoskeleton, and are bilaterally symmetrical
 * ex. fish, amphibians, reptiles, birds, and mammals

Adaptations of Land Animals Skeleton Systems Reproduction: Returning to water to lay eggs or secreting protective shells over eggs or developing eggs within bodies