Animal Biology LAB EXAM #1 Review

Stereo Head

The moveable top portion of the microscope and the stereo head holds the two adjustable eyepieces.

-Two pairs of antennae -Biramous appendages = two functions -Primarily aquatic (except for some isopods)

Phylum Arthropoda, Subphylum Crustacea (Crayfish)

Diopter

It compensates for the focusing differences between the left and right eye. Setting it correctly prevents eye strain

Fine adjustment knob

Moves the stage slightly to sharpen the image for focusing on high power.

Principle of parsimony

Phylogeny with the fewest changes is mostly likely to be true

-Bilateral symmetry -Trocophore larvae -Triploblastic protosomes Segmented worm-like body form (metamerism) -Unique locomotion -Paired epidermal setae -Closed circulatory system -Dorsal ganglia -Ventral nerve cord -Metanephridia (simple kidneys) -Complete digestive tract -Regenerative abilities -Mono/dioecious

Phylum Annelida

-Polychaete worms: clam worms, blood worms, fireworms and sea mouse -Relatively long setae & developed parapodia -Adaptations for active, mobile lives (Prostium w/ eyes & tentacles)

Phylum Annelida, Class Errantia (Clam Worm, Clam Worm cross section, Clam Worm Parapodia, Sea mouse)

- Oligochaete Worms: Mostly marine tubeworms along w/ terrestrial & freshwater worms - Parapodia w/ reduced lobes or completely lacking parapodia - Setae closely associated w/ stiff body wall to help anchor in tubes & burrows - Head modified w/ tentacles

Phylum Annelida, Class Sedentaria (Earth Worm, Earthworm Cross Section, Leech)

-Range in body size (0.1mm-4mm) -Active animals (diverse habitats with diverse diets) -Metamerism and tagmatization body forms -Mouthparts (chelicerae & mandibles) -Jointed stiff exoskeleton that shows ecdysis -Uniramous or Biramous -Homecoel -Open circulatory system -Metamorphosis

Phylum Arthropoda

-Chelicerae (feeding appendages) -Most have two tagmata: Cephalothorax (prosoma) & Abdomen (opisthosoma)

Phylum Arthropoda, Subphylum Chelicarata (Spider & Horseshoe Crab)

-Exoskeleton & metamorphosis key to success on land -Bodies divided into 3 tagmata: Head, thorax, abdomen -Evolution of flight (WINGS)

Phylum Arthropoda, Subphylum Hexapoda (Grasshopper & Insect wings)

-Radial Symmetry -Gastrovascular cavity (incomplete gut) -cnidocytes -Diploblastic (two germ layers) -Gelatinous mesoglea - Polyp & medusa forms (alteration of generations)

Phylum Cnidaria

-True Jellyfish -Medusa dominant -Dioecious -Cnidocytes present in gastrodermis & epidermis -Rhopalium (sensory organ containing nerves)

Phylum Cnidaria , Class Scyphozoa (Moon Jelly)

-Lack Medusa stage -Colonial or solitary body plan -Radial Symmetry (often in multiples of 6 or 8) -Gastrovascular cavity divided into sections by mesenteries or septa

Phylum Cnidaria, Class Anthozoa (Sea Anemone, Coral)

-Hydromedusa, Medusa, & Hydra forms -Cnidocytes in epidermis -Extracellular digestion -Asexual/sexual reproduction **Contains a layer called a velum, that contracts & aids in movement of hydrozoans**

Phylum Cnidaria, Class Hydrozoa (Hydra & Obelia (Medusa & polyp form))

- Bilateral symmetry - Coelomate lophotrochozoan protostomes - Monoecious and Dioecious forms - Nervous system w/ highly specialized sensory organs - Open circulatory system (except Class Cephalopoda) - Complete digestive tract - Metanephridia: simple kidneys

Phylum Mollusca

- Covered by a sheet-like mantle & shell w/ 2 valves - Sedentary lifestyle (lack of head, no radula, use gills for filter feeding) -Most are dioecious w/ external fertilzation - Unique locomotion including swimming & burrowing - Produce pearls to remove sand or parasite in special substance

Phylum Mollusca, Class Bivalva (Clam)

- Reduced shell, muscular mantle encloses viscera - Locomotion w/ jet propulsion through funnel or siphon - Color changes possible due to chromotaphores - Anterior portion of foot modified into a circle of tentacles - Highly developed nervous & sensory system (relatively large brains) - Closed circulatory system - Efficient active predators

Phylum Mollusca, Class Cephalopoda (Squid)

- Ontogenetic torsion (180 degree twisting of visceral mass, gills, & anus very close to mouth) - Open circulatory system - Well-developed sensory structures -Monoecious & dioecious

Phylum Mollusca, Class Gastropoda (Snail radula & snail shell)

- Chitons (many plate bearers) - Muscular foot for attachment to solid substrates - Shell w/ 7 or 8 dorsal plates

Phylum Mollusca, Class Polyphacophora (Chiton)

-Acoelomates -Organ system level of organization -Extra & intracellular digestion -Monoecious -Specialized neurons -Active carnivorous hunters

Phylum Platyhelminthes

-Lack a mouth and digestive tract in all life stages -Adults consist of long series of repeating units called proglottids w/o scolex for attachment

Phylum Platyhelminthes, Class Cestoda (Tapeworm & Immature, Mature, Gravid Proglottids)

-Adapted to be parasitic -Organs for adhesion -Increased reproductive capacity -Monoecious -Incomplete gut -Infect liver, blood, lungs, etc

Phylum Platyhelminthes, Class Trematoda (Fluke)

-Flattened shape provides lots of surface area for diffusion of gases and waste -Digestive tract incomplete -Most are monoecious -Neurons for sensory, motor and association -Flame cells or protonephridia present for excretion

Phylum Platyhelminthes, Class Turbellaria (Planaria)

Ocular Lens

The eyepieces through which the viewer looks at the specimen. The eyepieces are typically set at 10x magnification. It is also possible to upgrade to a higher magnification level.

Coarse adjustment knob

Moves the stage up and down for focusing

-"Many footed" -Two tagmata (head and trunk) -Uniramous appendages

Phylum Arthropoda, Subphylum Myriapoda (Centipede & Millipede)

Stage plate

Platform where the specimen is placed for viewing

Illumination

Some microscopes only have one source of illumination, top or bottom. The top lighting shines down on the specimen and reflects light off them. The bottom lighting transmits light up through the stage to show translucent specimens.

Objective lens

Stereo microscopes have two separate objectives, each one connecting to one of the eyepieces. The eyepiece and the objective lenses collectively determine the magnification of the microscope. They can have a fixed single objective, a rotating multiple lens turret or a zoom. It allows you to change the magnification levels depending on the applications.