bio2

• Animals


  • Heterotrophs
  • Multicelled
  • Ingest and digest food inside the body
  • Reproduce by sexual reproduction
  • Mostly motile
  • Composed of diploid cells
  • Have tissues except sponges
  • Developed from 2 diploblastic or 3 triploblastic germ layers
• Body symmetry


  • Asymmetric
  • Radial
  • Bilateral
• Number of Germ Layers

  • Diploblastic with 2 germ layers
  • Triploblastic with 3 germ layers
• Ectoderm


  Forms the outer covering, CNS (central nervous system)
• Mesoderm


  Forms the internal organs
• Endoderm


  Forms the lining of the digestive tract, liver and lungs of the vertebrates
• Fate of the blastopore

  • Protostome - the blastopore will develop into the mouth first
  • Deuterostome - the blastopore will develop into the anus first
• Presence or absence of a body cavity

  • Acoelomate - no coelom
  • Coelomate - have a cavity lined with a tissue derived from the mesoderm
  • Pseudocoelomate - with body cavity but without lining
• Cephalization


  Nerve cells and sensory structure become concentrated at one end (anterior)
• Segmentation


  Division of a body into similar repeating units along the main axis
• Animal


  • Multicelled heterotroph with unwalled cells
  • Ingest food and digest it inside the body
  • Mostly motile at some point of life
  • Composed of diploid cells
  • Reproduce by sexual reproduction, no alternation of generation
  • Have tissues (except sponges) developed from either 2 (diploblastic) or 3(triploblastic) germ layers
• Classification of Animals


  • Presence or absence of true tissues
  • Body Symmetry
  • Number of embryonic germ layers
  • Fate of the Blastopore
  • Presence or absence of a body cavity
  • Cephalization and segmentation
  • Feeding Mechanism
• Body Symmetry


  • Asymmetric- Body cannot be divided into halves or mirror image
  • Radial- Body parts are repeated along a central axis
  • Bilateral- Body can be divided into half, mirror-image
• Number of Germ Layers

  • Diploblastic- with only 2 germ layers
  • Triploblastic- with 3 germ layers
  • Ectoderm- Forms the outer covering, CNS
  • Mesoderm- Form the internal organs
  • Endoderm- Forms the lining of the digestive tract, liver and lungs of vertebrates
• Fate of the Blastopore

  • Protostome- The blastopore will develop into the mouth first
  • Deuterostome- The blastopore will develop into the anus first
• Presence or Absence of a Body Cavity

  • Acoelomate- No coelom
  • Coelomate- Have a body cavity lined with a tissue derived from the mesoderm
  • Pseudocoelomate- With body cavity, but without lining
• Cephalization


  • Nerve cells and sensory structures become concentrated at one end (anterior)
• Segmentation


  • Division of a body into similar repeating units along the main axis
• Feeding Mechanism


  • Herbivore- Feed on plants
  • Carnivore- Feed on animals
  • Omnivore- Feed on both plants and animals
  • Insectivore- Feed on insects
  • Frugivorous- Feed on fruits
  • Detritus- Feed on decaying matter
  • Parasite- Feed on host
  • Filter Feeder- Filter the water to trap small particles
• Major Animal Phyla


  • Porifera
  • Cnidaria
  • Platyhelminthes
  • Mollusca
  • Annelida
  • Nematoda
  • Arthropoda
  • Echinodermata
  • Chordata
• Porifera


  • Sponges
  • Without true tissues
  • Asymmetric
  • Hermaphrodite (sperms released in water)
  • Aquatic (Marine or Fresh)
  • Filter Feeder
  • Motile larva, sessile adult
• Cnidaria


  • Corals, sea anemones, Jellies, Hydra, Portuguese man-of-war
  • Radial Symmetry
  • Diploblastic
  • Have tentacle ringed mouth with nematocyst
  • Divided into 2: Medusa- Jellies, shaped like a bell; Polyps- Sea Anemones, hydra, Mouth on the upper surface
• Platyhelminthes


  • Flatworms
  • Bilateral symmetry
  • Triploblastic
  • Protostome
  • Acoelomate
  • Can be free-living (Planaria) or parasitic (Tapeworm and flukes)
• Mollusca


  • Mollusks
  • Bilateral symmetry
  • Triploblastic
  • Protostome
  • Coelomate
  • Gastropods- One piece shell; (Snails), No shell; (Nudibranchs, slugs)
  • Bivalves- 2 shells; mussels, oysters, clams
  • Cephalopods- Head-footed; Squid, octopi
• Annelida


  • Segmented Worms
  • Bilateral symmetry
  • Triploblastic
  • Protostome
  • Coelomate
  • Marine Polychaetes, Oligochaetes (earthworms), leeches
• Nematoda


  • Unsegmented Roundworms
  • Bilateral symmetry
  • Triploblastic
  • Protostome
  • Pseudocoelomate
  • Free-living- C. elegans
  • Parasitic- A. lumbricoides, Wutchireria bancrofti, pinworms, hookworms
• Arthropoda


  • Arthropods (Joint-legged)
  • Most diverse phylum
  • Bilateral symmetry
  • Triploblastic
  • Protostome
  • Coelomate
  • Have hardened exoskeleton made of chitin
  • Undergo ecdysis
• Arthropoda Subgroups


  • Chelicerates
  • Crustaceans
  • Insects
• Chelicerates


  • Cephalothorax
  • Horseshoe crab
  • Arachnids
  • Four pairs of walking legs
  • Spiders, scorpions, ticks, mites
• Crustaceans


  • Aquatic; with 2 pairs of antennae
  • Crabs, lobster, shrimps
• Insects


  • Most diverse arthropods
  • Have three part body: Head, Thorax, Abdomen
  • Have one pair of antennae
  • Have 3 pairs of legs
  • Have 2 pairs of wings (except Dipterans)
• Echinodermata


  • Echinoderms
  • Sea Star, brittle star, sea cucumber, sea urchin
  • Radial symmetry for adults and bilateral for larvae
  • Evolved from bilateral ancestors
  • Triploblastic
  • Deuterostomes
  • Coelomate
• Chordata


  • Fishes, amphibians, reptiles, birds, mammals
  • Bilateral symmetry
  • Triploblastic
  • Deuterostomes
  • Coelomate
  • Can be exothermic or endothermic
• Chordata Subgroups


  • Urochordata- Tunicates
  • Cephalochordata- Lancelets
  • Agnatha- Jawless fishes
  • Chondricthyes- Cartilaginous fishes
  • Osteicthyes- Bony Fishes
  • Amphibia- Amphibians
  • Reptilia- Reptiles
  • Aves- Birds
  • Mammalia- Mammals
• Tissue


  A group of cells with similar structure and function, as well as similar extracellular substances located between the cells
• Types of Tissues


  • Epithelial
  • Connective
  • Muscle
  • Nervous
• Histology


  The microscopic study of tissue structure
• Epithelial Tissues


  • Found throughout the body, covers internal and external surfaces
  • Lines Cavitites
• Functions of Epithelial Tissues

  • Protect underlying structures
  • Act as barriers
  • Permit the passage of substances
  • Secrete substances
  • Absorbs substances
• Classification of Epithelia by Cell Shape

  • Squamous- One Flat, scale-like
  • Cuboidal- Cube-like
  • Columnar- Tall and thin