250 likes | 388 Views
Biology Notes: Unit 7. Exploring Invertebrates. I. General Characteristics of Animals. A. Heterotrophic- Must take in food B. Mobility- Most animals can perform rapid, complex movements C. Multicellularity- Made of more than one cell
E N D
Biology Notes: Unit 7 Exploring Invertebrates
I. General Characteristics of Animals • A. Heterotrophic- Must take in food • B. Mobility- Most animals can perform rapid, complex movements • C. Multicellularity- Made of more than one cell • D. Eukaryotic- Made of true cells with nucleus and organelles
II. Invertebrates • Animals without a backbone
III. Invertebrate Characteristics • A. Internal Body Cavities • 1. coelom- body cavity • A. acoelomates- animals with no body cavity • B. pseudocoelomates- animals with a false body cavity • C. coelomates- animals with a true body cavity
B. Skeletons • 1. hydrostatic- use water contained under pressure • 2. exoskeleton- a rigid external skeleton • 3. endoskeleton- an internal skeleton exoskeleton endoskeleton
C. Body Symmetry • 1. asymmetrical- irregular in shape • 2. radial- body parts arranged around a central axis • Bilateral- right and left sides that are mirror images
D. Feeding and Digestion • 1. intracellular digestion- digestion within special body cells • 2. gastrovascular cavity- a digestive sac with a single opening • 3. extracellular digestion- food is digested by special organs
E. Circulatory System • 1. open system- blood is not contained in vessels • 2. closed system- heart circulates blood inside blood vessels
F. Methods of Respiration • 1. respire through the skin (earthworm) • 2. use gills (crayfish, clams) • 3. book lungs (spider) • 4. trachea (insects)
Methods of Respiration gills Book lungs trachea
F. Methods of Excretion • 1. flame cells (flatworms) • 2. nephridia (mollusks, earthworms) • 3. malpighiantubules (terrestrial arthropods)
H. Response • 1. centralization- concentration of nerve cells at anterior end • 2. cephalization- anterior developed into a definite head
I. Types of Reproduction • 1. asexual-clone of the parent • regeneration: can regrow lost body parts • Budding :separation of a parent into 2 or more individuals • 2. hermaphrodites- contains both male andfemaleorgans • 3. sexual- fusion of egg and sperm
IV. Invertebrate Phyla A. Porifera- sponges