A. A.INTRODUCTION
1. Animals are heterotrophic; they must take in food.
2. Predators have bilateral symmetry, good musculature sense organs and a well developed nervous system.
3. Bilareral symmetry (cut only 2 equals halves) and cephalization (definite head and sense organs with brain) are present.
4. Phylogenetic tree indicates animal origins to be flagellated protozoans.
B. ANIMAL CLASSIFICATION
1. Body plan- sac and tube within a tube;
a. sac plan- animals have only 1 opening, wastes enter and exit here. b. tube within tube plan- 2 openings.
2. Symmetry
a. defined: the general form or the mirror images of each other. b. types:
i. Asymmetry-no symmetry is present.
ii. Radical symmetry- animal is circularly organized regardless of angle, cut to bottom two equal halves result.
iii. Bilateral symmetry- animal has a definite right and left side, thus only cut down center will result in equal halves.
C. C. GERM LAYERS
1. defined: original layers from which all organs and tissues evolve; 2. types: diploblastic, triploblastic.
a. diploblastic- animal with 2 germ layers, endoderm and ectoderm (tissues level of organization.
b. triploblastic- animals have 3 layers endoderm, ectoderm and mesoderm. (organ level of development)
i. The endoderm forms the digestive system. The ectoderm forms the body covering and the nervous systems.
D. BODY CAVITY- SURROUNDS THE DIGESTIVE SYSTEM
1. acoelomate- no cavity
2. psuedo coelomate- incompletely lined cavity- partial 3. coelomates
a. schizocoelomates- mesoderm arises from cells near blastopore which split out and form coelom.
b. enterocoelmaters- mesoderm arises and out pockets the endoderm.
E. SEGMENTATION- repeating units
F. LARVAL STAGE- an independent embryonic stage that is capable of acquiring its
own food.
G. LOCOMOTION- exhibition of moving parts.
H. UNIQUE FEATURES- features among one group of animals and not among others.
________________The Phylogenetic Tree
SPONGE
1. Classified according to rays on skeletal spicules 2. Aquatic
3. No germ layers, body cavity or segmentation, organization body plan.
4. Outer layer is just flattened epidermal cells with a gelatinous middle-collar celled inner layer.
5. Symmetry is radial if present.
6. Flagellum of collar cells in the inner layer produces a water current bringing food in through pores.
7. Food is engulfed by collar cells and digested in the food vacuoles (intracellular). 8. The amoeboid cells transport food throughout the body cells are located in
jelly-like layers.
10. Excretion- amoeboid cells;
11. Oxygen is secured from the water;
12. Reproduction is sexual and asexual. Asexual by buddline sexual via gametes produced by the amboid cells.
HYDRA
1. Fresh water, getting oxygen from water.
2. Diploblastic, sac body plan, with radial symmetry. 3. Wastes are deposited in cavity and exit through mouth. 4. No body cavity or segmentation: tissue level of organization.
5. Stinging cells called cnidiblasts are located in the tentacles and are used for food and defense.
6. Food enters mouth ->gastro vascular cavity-> cells here secrete enzymes to begin digestion. Digestion is completed in food vacuoles of cells of inner layer. 7. Food nutrients diffuse throughout body.
8. A nerve net composed of nerve cells along with contractile fibers aid in movement.
9. Reproduction is sexual and asexual. Reproduction is sexual by budding and regeneration. Sexual via gametes produced by embryonic cells, which form ovaries and testes.
Planaria
1. Contains the sac body plan, triploblastic with bilateral symmetry.
2. There is no body cavity or segmentation with the organ level of organization. 3. Fresh water flat worm that gets its food and oxygen from the water.
4. Liquid wastes collected by flame cells exit through pores.
5. Food enters pharynx which is extended through mouthÆ gastrovascular canal. Food is digested in cavity by secretrons of those cells. It is completed in the food vacuoles of those cells.
6. Food diffuses through body.
7. There are 3 muscular layers, which along with cilia and gland secretion aids in movement.
8. The nervous system is a ladder type with a “brain” and sensory cell in body wall and eyespots; to aid in stimuli & light reaction.
Ascaris
1. Tube within a tube body plan with a pseudocolon. 2. Parasitic, triploblastic, unsegemented worm.
3. Has achieved organ level of organization with bilateral symmetry.
4. Movement in a whip-like action due to the muscles and nervous system which consists of nerve cord and nerve ring.
5. Food is digested by host and enters by mouth.
6. Food diffuses from intestine to pseudocoel and disperses throughout body. 7. Wastes are removed through the excretory canal through the excretory pore. 8. Sexes are separate, sexual reproduction.
Testes=sperm Ovary= egg
9. O2 is taken from the food provided by host.
Clam
1. Inactive, filter feeder using a muscular hatchet foot for locomotion. 2. Aquatic Schizocoelomate with no segmentations.
3. Contains a bivalve exoskeleton, with no cephalization.
4. Food is ingested through incurrent siphon through mouthÆ esophagusÆ stomachÆ intestineÆanusÆ excurrent siphon.
5. Circulation is open if blood flows out of blood vessel closed if always in blood vessels. Here it is open blood, blue flows in sinuses.
6. The kidney removes liquid wastes, gills secure oxygen. 7. The ganglion nerves insure reaction to stimuli.
8. Has larva stage, trochopore.
Earthworm
1. A segmented, schizocoelmate that lives on land and inactively secures its food. 2. Moves with use of its 2 layers of muscles and setae; no skeleton no
cephalization.
3. The earthworm is not a predator, but a scavenger that feeds on leaves or any other organic matter in soil.
4. Earthworms are hermaphrodites, with no larval stage, eggs and sperm are deposited in the clitellum.
5. The Nephridia remove liquid wastes.
6. The closed circulatory system consists of red blood, 5 pairs of “hearts”, and 2 large blood vessels.
7. Oxygen enters through moist skin “cuticle”.
8. Nervous structures include the brain, solid ventral, nerve cord and nerves. 9. Food enters mouth Æ esophagus Æ crop Æ Gizzard Æ intestine Æ anus.
Crayfish
1. Since the crayfish lies in wait for food, it is termed an active predator, utilizing its jointed appendages, legs and swimmerets for movement.
2. The aquatic, segmented animal utilizes its gills for securing oxygen.
3. This schizocoelomate has an exoskeleton composes of chitlin, cover the body regions (cephalothorax abdominal).
4. The blue blood, heart and blood vessels and hemocoel complete the open circulatory system.
5. The anterior green gland removes liquid wastes.
6. Food enters mouthÆ esophagusÆ stomachÆ intestineÆanusÆdigestive system.
7. A brain, ventral solid nerve cord and nerves comprise the nervous system. 8. Muscles are attached to the exoskeleton for support.
9. Sexes are separate.
Star fish
2. Although it’s not segmented this enterocoelomate utilizes its skin gills for respiration.
3. The spiny endoskeleton provides protection as it actively seeks its prey. 4. There is no definite head region.
5. Muscles are present along with a nervous system composes of a nerve ring and 5 cords.
6. The starfish eats clams by inverting stomach through mouth. Food then passes through esophagus, stomach, intestine, and anus.
7. The open “circulatory system” consists of coelmic fluid where in circulatory and excretory functions are carried out.
8. The sexes are separate, dipleurla larva, regeneration.
Frog
1. The frog is amphibian, land and water.
2. This predator utilizes internal skeleton and muscles in locomotion. It is an enterocoelomate.
3. A definite head region is present along with specialization of parts. 4. The kidney removes wastes, passes them to the ureters and bladder.
5. The brain, spinal cord, nerves, tympanic membrane spinal and cranial nerves make up the nervous system.
6. The sexes are separate.
7. Oxygen is secured oxygen through lungs and through skin.
8. The 3 chambered heart and blood vessels comprise the closed circulatory system.
