BIO112 Flashcards

THE KINGDOM ANIMALIA

  • Animals lack cell walls and chloroplasts.
  • They are heterotrophic and eukaryotic.
  • Classification is based on architectural designs, symmetries, body designs, and patterns of organization.
  • Divided into invertebrates and vertebrates.

CLASSIFICATION OF INVERTEBRATES AND VERTEBRATES

  • Invertebrates:
    • Kingdom Protista: Protozoa (Sacromastigophora, Labyrinthomorpha, Apicomplexa, Microspora, Ascetospora, Myxozoa, Ciliophora).
    • Kingdom Animalia: Porifera (Calcarea, Demospongiae, Sclerospongiae, Hexactinellida), Coelenterata (Cnidaria) (Hydrozoa, Scyphozoa, Cubozoa, Anthozoa), Platyhelminthes (Turbellaria, Monogenea, Trematoda, Cestoda), Nematoda (Aphasmida, Phasmida), Annelida (Polychaeta, Oligochaeta, Archiannelida, Hirudnea), Mollusca (Polyplacophora, Aplacophora, Monoplacophora, Gastropoda, Bivalvia, Scaphopoda, Cephalopoda), Arthropoda (Trilobitomorpha, Chelicerata, Uniramia, Crustacea), Echinodermata (Crinoidea, Ophiuroidea, Asteroidea, Echinoidea, Holothuroidea).
  • Vertebrates:
    • Phylum Chordata: Protochordata, Craniata (Vertebrata).
    • Superclass Agnatha: Myxini, Cephalaspidomorphi.
    • Superclass Gnathostomata: Chondrichthyes, Osteichthyes, Amphibia, Reptiles, Aves, Mammalia.

ARCHITECTURAL DESIGNS OF ANIMALS

  • Symmetry:

    • Asymmetry: No central axis (e.g., sponges).
    • Bilateral symmetry: Divides into right and left mirror images (e.g., vertebrates).
    • Radial Symmetry: Divides into mirror images through oral-aboral axis (e.g., cnidarians).

  • Terms to Locate Regions:

    • Aboral: Opposite the mouth.
    • Oral: End bearing the mouth.
    • Anterior: Head end.
    • Posterior: Tail end.
    • Distal: Away from attachment point.
    • Proximal: Toward attachment point.
    • Dorsal: Back or upper surface.
    • Ventral: Belly or lower surface.

  • Cephalization:

    • Concentration of nervous tissue and sense organs at the front end.
    • Associated with bilateral symmetry.
    • Advantages: Complex neural system, clustering of senses.

  • Metameric Segmentation:

    • Serial repetition of body segments along the longitudinal axis.
    • Segments called metameres or somites.
    • Seen in annelids, arthropods, and chordates.

LEVELS OF ORGANIZATION

  • Protoplasmic: Unicellular (protists).
  • Cellular Aggregates: Loose association of cells (sponges).
  • Cell-Tissue: Similar cells form tissues (cnidarians).
  • Tissue-Organ: Tissues organized into organs (Platyhelminthes).
  • Organ-System: Organs working together (Nemertean worms and higher phyla).

BODY DESIGN

  • Sac-like bodies: Single opening for mouth and waste.
  • Tubular bodies: Gut cavity with anterior and posterior openings.

DIVISIONS BY BODY LAYERS

  • Diploblastic Animals:
    • Two germ layers: ectoderm and endoderm.
    • Non-cellular mesoglea between layers (Coelenterates and Ctenophores).
  • Triploblastic Animals:
    • Three germ layers: ectoderm, mesoderm, and endoderm.
    • Bilaterally symmetrical with organ-system level organization.

BODY CAVITY

  • Acoelomate: No body cavity, mesodermal region filled with cells.
  • Pseudocoelomate: False body cavity, not completely lined by mesoderm.
  • Coelomate: True body cavity, completely lined by mesoderm.

ANIMALLIKE PROTISTS (THE PROTOZOANS)

  • Protozoa: Unicellular, complex organisms.

  • Classification based on nuclei, reproduction, and locomotion.

  • Characteristics:

    • Unicellular, microscopic.
    • No germ layer, tissues, or organs.
    • Various nutrition types and locomotion methods.
    • Asexual and sexual reproduction.

  • Classification:

    • Phylum Sacromastigophora: amoebae and flagellates.
      • Possess flagella or pseudopodia for locomotion.
        Subphylum Mastigophora: whip-bearing, flagella for locomotion. Autotrophic or heterotrophic.
        *Class Phytomastigophorea: possess chloroplasts, autotrophic nutrition. Examples: Euglena, Volvox.
        *Class Zoomastigophorea: lack chloroplasts, heterotrophic. Examples: Trypanosoma, Trichomonas.
        Subphylum Sarcodina: pseudopodia for movement and food gathering; naked or with tests; mostly free-living. Examples: Amoeba, Entamoeba.
    • Phylum Labyrinthomorpha: protozoans living on algae.
    • Phylum Apicomplexa: apical complex for penetrating host cells, parasitic. Examples: Plasmodium.
    • Phylum Microspora: intracellular parasites.
    • Phylum Acetospora: parasites in invertebrates.
    • Phylum Myxozoa: parasitic.
    • Phylum Ciliophora: cilia for locomotion and feeding currents. Examples: Paramecium.

THE SPONGES AND CNIDARIANS

PHYLUM PORIFERA (SPONGES)

  • Simplest multicellular animals.
    • Porifera are filter feeders that depend on water currents.
  • Characteristics:
    • Multicellular, mesenchymal origin.
    • Body with pores, canals, and chambers.
    • Aquatic, mostly marine.
    • Radial symmetry or none.
    • No organs or true tissues; filter feeders.
    • Asexual and sexual reproduction.
  • Canal Systems:
    • Asconoid: Simplest, spongocoel, single osculum (e.g., Leucosolenia).
    • Syconoid: Incurrent canals, spongocoel, single osculum (e.g., Scypha).
    • Leuconoid: Complex, many flagellated chambers, multiple oscula (e.g., Euspongiae).
  • Cell Types:
    • Choanocytes: Collar cells, flagellum for water currents.
    • Pinacocytes: Outer epithelium.
    • Porocytes: Tubular cells forming pores (asconoid sponges).
    • Archaeocytes: Amoeboid cells, digestion, secrete spicules or spongin.
  • Support: Skeleton of spicules (calcium carbonate, silica, or spongin).
  • Classification:
    • Class Calcarea: Calcium carbonate spicules, all canal systems (e.g., Leucosolenia).
    • Class Hexactinellida: Siliceous spicules of 6 rays (e.g., Pheronema).
    • Class Demospongiae: Silica spicules or spongin fibers (e.g., Spongilla).
  • Economic Importance:
    • Food for some molluscs.
    • Commensal, protective houses.
    • Dried skeletons for scrubbing and bathing.

THE CNIDARIANS (COELENTERATES)

  • Cnidarians have cnidocytes with nematocysts.
  • Characteristics:
    • Mostly marine.
    • Diploblastic (ectoderm and endoderm).
    • Free-swimming or sessile.
    • Cnidocytes for capturing food and defense.
    • Tissue-level organization.
    • Gastrovascular cavity with a single opening (mouth).
    • Skeleton composed of Calcium carbonate.
    • Two basic forms: Polyp and medusa.
    • Alternation of generation (Metagenesis).
  • Classification:
    • Class Hydrozoa: Cnidocytes in epidermis, medusa with velum (e.g., Hydra, Obelia).
    • Class Scyphozoa: Small polyp, medusa prominent (e.g., Aurelia).
    • Class Cubozoa: Medusa cuboidal, marine (e.g., Chironex).
    • Class Anthozoa: Polyps colonial or solitary, no medusa (e.g., Metridium).
  • Examples:
    • Hydra: Cylindrical tube, basal disc, tentacles, nerve net.
    • Obelia: Trimorphic colony (polyps, gonangia, medusa).