Zoology_Lab_Study_Guide_Midterm_Exam

Taxonomic Classification

• Taxonomic Levels

  • Domain = Darn

  • Kingdom = King

  • Phylum = Philip

  • Class = Came

  • Order = Over

  • Family = For

  • Genus = Good

  • Species = Sex

Developmental Biology

• Protostome vs. Deuterostome

  • Radial or spiral cleavage patterns in embryo development

  • Cleavage leads to multiple cells:

    • 8-cell stage

    • Morula: 16 cells

    • Blastula: 32-64 cells forming a sphere

    • Gastrula: 64+ cells forming a hollow sphere with a notch

  • Free swimming larvae can take multiple forms based on species

Phylum Porifera (Sponges)

• Basic Structure

  • Flagella creates water flow throughout the sponge

  • Water Flow Path:

    • Incurrent canal ➜ Prosopyle ➜ Radial canal ➜ Apopyle ➜ Spongocoel ➜ Osculum

  • Anatomy Components:

    • Radial canal (outer wall)

    • Spongocoel (inner cavity)

    • Osculum (exit for water)

• Characteristics

  • No true tissues present

  • Reproduction: sexual and asexual methods

  • Majority belong to class Demospongiae

  • Classes Differences:

    • Demospongiae: Siliceous/spongin fibers, non-6 rayed spicules

    • Calcispongiae: Composed of calcium carbonate

    • Hexactinellida: Possesses 6 rayed spicules

Phylum Cnidaria

• General Features

  • Radial symmetry and bell shape

  • Life cycles include Medusa and Polyp stages

  • Diploblastic structure

  • Body covered with epidermis, no cephalization present

  • Acoelomate structure

• Anatomical Characteristics

  • Represented by ecto and endodermal muscle fibers

  • Mouth and anus share a single opening

  • Lacks defined sense organs and excretory systems

  • Network of neurons present

• Reproduction

  • Sexual reproduction through medusa forming polyp

  • Asexual reproduction through budding in polyps

Phylum Platyhelminthes (Flatworms)

• General Features

  • Bilateral symmetry with flat body shape

  • Triploblastic structure with ciliated epidermis

  • Present cephalization

  • Acoelomate design

• Body Systems

  • Muscular structure: circular and longitudinal muscles

  • Incomplete digestive system

  • Excretion via flame cells

  • Ladder-like nervous system with cerebral ganglia and transverse nerve cords

  • Eyespots present for light detection

  • Reproduction: hermaphroditic; can reproduce asexually via binary fission

Phylum Mollusca

• Class Bivalva (Clams)

  • Structure features include umbo on the external surface and a mantle

  • Mantle cavity serves as leftover space for various functions

  • Gills with large internal wings for gas exchange

  • Nacreous layer present, producing the pearl-like mantle cover

• Class Gastropoda (Snails)

  • Mouth located at the front end, eyes protrude on the head

  • Foot positioned on the bottom, with tentacles beneath the eyes

  • Visceral mass housed inside the mantle

• Class Cephalopoda (Squid)

  • Distinct features include large fins on body top, with eyes beneath the mantle collar

  • Gills spread out on the sides of the mantle

  • Females possess ovaries coming from the top of the body; ink sac hidden under organs near eyes

Phylum Annelida

• General Features

  • Protostome development with eucoelomate arrangement

  • Closed circulatory system, particularly in earthworms

  • Segmented body structure with circular muscles

  • Numerous setae present

  • Complete digestive system including mouth and anus

Phylum Nematoda (Roundworms)

• General Features

  • Lacks true segmentation, known as pseudocoelomates

  • Round body shape, featuring longitudinal muscles only

  • Protostome and bilateral symmetry present

  • Triploblastic body design with some degree of cephalization

• Body Systems

  • Complete digestive tract operational from mouth to anus

  • Excretion through anus, designated canals and specialized cells

  • Dorsal and ventral nerve cords, along with a ring of ganglia in the head

  • Presence of labial and cephalic sensilla organs

• Reproduction

  • Diecious in nature, does not reproduce asexually

Phylum Arthropoda

• General Characteristics

  • Common traits among arthropods include:

    • Jointed appendages

    • Chitinous exoskeleton

    • Segmentation (tagma)

    • Open circulatory system with hemocoel

• Subphylum Chelicerata

  • Inhabitants: spiders, scorpions, horseshoe crabs, ticks, and mites

  • Class Merostoma (Horseshoe Crabs): Possess blue blood, characterized by 10 legs with pedipalps and chelicerae

  • Class Arachnida (Spiders): Body segmented into cephalothorax and abdomen

• Subphylum Myriapoda

  • Class Chilopoda (Centipede):

    • Carnivorous

    • 1 leg per segment, flat body

    • Antennae and venom present

  • Class Diplopoda (Millipede):

    • Herbivorous

    • 2 legs per segment, rounded body

    • Legs extend from the bottom of the body

• Subphylum Crustacea

  • Predominantly gill-breathing

  • Two pairs of antennae present

  • Mandibles and maxillae for all classes

  • Biramous appendages

  • Cephalothorax structure

• Additional Features

  • Hauplius Larva: Notable developmental stage

  • Classification of Decapoda, featuring 10 legs

  • Sexual dimorphism observable in swimmerets on abdomen

  • Telson referred to as tail region

Subphylum Hexapoda

• Class Insecta

  • Tracheal respiratory system

  • Possesses one pair of specialized mouthparts/mandibles

  • Typically 6 uniramous walking legs

  • Body divided into head, thorax, and abdomen

  • Many species feature wings and compound eyes