Download - Monday, April 8 th
MONDAY, APRIL 8TH
Introduction to Animals
Objective: Be able to identify if an organism is in the animal kingdom based off characteristics
10 Animal Phylu
ms
WHAT IS AN ANIMAL
MulticellularHeterotrophic EukaryoticReproduce sexually and asexuallyLack cell walls
SYMMETRYAsymmetry-no body plan(sponges)Radial Symmetry-radiate from center
(jelly fish)Bilateral Symmetry-identical halves
when cut from head to tail.
Anatomical Terminology
Superior (toward head) Inferior (toward feet) Dorsal (toward back) Ventral ( toward front) Medial (towards center) Lateral (towards outside)ProximalDistal
BODY PLANcoelom - body cavity to house organs. An evolutionary advantageacoelomate - no body cavity presentPseudocoelomate – partial body cavity
Introduction to Animals Germ Layers
Endoderm inner layer of cells
Ectodermouter layer of cells
Mesoderm layer of cells
between the endoderm and ectoderm
10 Animal Phylu
ms
PHYLUM PORIFERA
FEEDING: water is drawn in through pores into a central cavity and out of opening called OSCULUM
Lack TRUE Tissues Sessile (doesn’t
move)
SPONGES
2 Tissue LayersHermaphrodites
Ectoderm & Endoderm
Egg & Sperm – Sexual reproduction results when sperm are drawn to other sponge
Capable of RegenerationNO Tissues or coordination between parts
Check these
Porifera out
PHYLUM CNIDARIAHYDRA, SEA
JELLY (JELLYFISH),
CORALS
2 Germ Layers**Muscles & Nerves
Endotherm & Ectotherm
Simplest Form**Radial Symmetry
** evolutionary advancement
Body is a sac with a central gastrovascular cavity and 1 opening (mouth and anus)
Carnivores: use nematocysts (tentacles) to capture prey
Can occur as POLYP (sessile) or MEDUSA (free swimming)
Reproduce by spawning
PHYLUM PLATYHELMINTHESFlatworms, flukes, tapewormsBilateral symmetry*3 tissue layers*
ectoderm/mesoderm/endodermmore complex organ systems
and true muscles*
only 1 openingReproduction:sexually - exchange sperm through internal fertilization
asexually - regenerationHermaphrodites
PHYLUM NEMATODA
roundwormsMost numerous of all animalscomplete digestive tract; 2 OPENINGS*
Reproduction is usually sexual w/ separate males and females
Fertilization is internalPseudocoelom*
PHYLUM ANNELIDA Segmented worms: earthworm, leech all have segments* Coelom (body cavity) - houses, cushions and protects
organs* Digestive system has specialized regions;Pharynx,
esophagus, crop, gizzard and intestines
Closed circulatory system; blood*
“brainlike” cerebral gangliaHermaphroditic but cross fertilize (exchange sperm and store it in clitellium)
The Giant Earthworm
PHYLUM MOLLUSCASnails, oysters, octopuscoelom*BODY: 3 main parts FOOT (movement)VISCERAL MASS (internal organs)MANTLE (shell)
Separate sexes with ovaries and testes in visceral mass -- reproduce sexually
1. Class Gastropoda - snails, slugs• single shell
CLASSES of Mollusks
2. Class Bivalvia - oysters, clams• suspension feeders • two shells
3. Class Cephlapoda - octopus, squid• built for speed -- carnivores,• reduced shell (beak)
PHYLUM ECHINODERMATA
Sea stars, sea urchinsRadial symmetryplates with spines embedded in soft body tissues.
External fertilization; separate males and females
simple nervous and sensory system; no excretory system
Gill-like structuresa sea star is a predator; it spits its stomach from its mouth and digests its food and brings the stomach back in.
PHYLUM ARTHROPODAMost successful group of animals ever to live
segmentation, hard skeleton and jointed appendages led to great success.
Appendages are modified for walking, feeding, flying, sensory reception, copulation and defense
Body covered with cuticle (exoskeleton) made of chitin; provides protection and place for muscle attachment
Grow by moltingSeparate sexes: males and females
Well developed sensory organs including eyes, olfactory receptors (scent), antennae (touch).
Cephalization is extensive (well defined head)
CLASS ARACHNIDAspiders, ticks, mites, scorpions
2 body parts (cephalothorax and abdomen)
anterior appendages are modified as pincers or fangs (chelicerae)
CLASS DIPLOPODA (millipedes)2 pair of legs per segmentsaprophytesCLASS CHILOPODA (centipedes)
1 pair of legs per segmentcarnivorous, poisonous
Class Insectaout number all other life forms combined
complex NS3 body regions (head, thorax and abdomen)
specialized mouthparts (mandibles for eating)
3 pairs of legsPollination
CLASS CRUSTACEA Lobsters, crawfish, shrimp, crab Most are aquatic Head and thorax fused into 1 cephalothorax
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