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Published byCaroline Lewis Modified over 10 years ago
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How Many Kingdoms? Extant 8 5 3 Extinct 2 Long Time with 1
Archaebacteria Archezoans Multicellular Animals Protozoans Green Algae Bryophytes Slime Molds Myxozoans True Fungi Bacteria Euglenoids Chrysophytes Brown Algae Red algae Tracheophytes 8 5 3 Extinct 2 1 Long Time with Prokaryotes only Original Cell
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Animal Features Multicellular Eukaryotes Heterotrophic Ingestion
Collagen Protein Connections Nerve and Muscle Tissues Diplontic (Gametic) Life History Gametes Oogamous with Flagellated Sperm Zygote to Blastula, perhaps Gastrulation Larval metamorphosis into Adult Ontogeny Recapitulating Phylogeny
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Domain Eukarya Kingdom Animalia Phylum Nematoda
Animals Domain Eukarya Kingdom Animalia Phylum Nematoda
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Nematode Body Organization
Nematode Body Organization
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embryo in shell of zygote
Caenorhabditis elegans is a bacteriovorous soil nematode, feeds on E. coli in vitro, is a genetic model organism, its genome is sequenced. N=6 XX=hermaphrodite XO=male protandrous Life cycle: 3 days at 20°C vulva embryo in shell of zygote anus mouth
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syngamy meiosis protandrous
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Domain Eukarya Kingdom Animalia Phylum Annelida
Animals Domain Eukarya Kingdom Animalia Phylum Annelida
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Lumbriculus variegatus : California mudworm
This is an aquatic oligochaete annelid Mouth feeds in sediments Tail extends toward water surface for gas exchange Body walls nearly transparent for easy observation For example: may count pulses of blood in dorsal vessel
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Lumbricus terrestris: Canadian nightcrawler or Earthworm
clitellum edge of ventral reproductive structures mouth anus
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The earthworm body is fundamentally segmented
The earthworm body is fundamentally segmented. Here is a typical segment: Each segment is filled with coelomic fluid, under some pressure, which provides “stiffness.” The segments near the head are specialized for other physiological functions.
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Circulatory: Gases, Nutrients, Wastes
Major Organ Systems in an Earthworm Excretory: Reproductive: Male Female Circulatory: Gases, Nutrients, Wastes Digestive: Food Intake Nutrient Absorption Muscular: Movement Dermal: Gas Exchange Nervous: Sensory and Coordination
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Segments separated by partitions that divide coelom
Characteristics More than 100 segments Segments separated by partitions that divide coelom Segments identical except when specialized and fused Anterior and posterior ends Cephalization specialized for burrowing Head contains sense organs Circular and longitudinal muscles 1 Mouth 2 Prostomium 3 Segment 4 Spermathecal openings 5 Female (oviduct) opening 6 Male (vas deferens) opening 7 Sperm groove 8 Papilla 9 Clitellum (saddle) 10 Paired setae (ventro-lateral) 11 Anus 12 Dorsal surface 13 Ventral surface
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Setae anchored during movement Circular muscles contract
Hydrostatic pressure increases in anterior coelomic cavities Body elongates pushing head forward Anterior setae grip ground Longitudinal muscles contract--posterior pulled along Coelomic divisions allow simultaneous contraction and expansion of segments A External view B Section through segment 1 Coelom 2 Circular muscle 3 Cuticle 4 Intestine 5 Dorsal blood vessel 6 Typhlosole 7 Epidermis 8 Nephridium 9 Longitudinal muscle 10 Seta 11 Protractor muscle 12 Retractor muscle 13 Ventral nerve cord 14 Subneural vessel 15 Ventral vessel 16 Septum
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Light receptors on head and tail--sense direction
Nervous Sensitive to tough, light, moisture, chemicals, temperature, and vibrations Light receptors on head and tail--sense direction Most sense organs and nerves control muscle contractions in individual segments Pair of ganglia in each segment coordinate movement with adjacent segments Cerebral ganglion in head controls total body Ventral nerve cord connects brain with ganglia 1 Anus 2 Intestine 3 Cerebral ganglion 4 Prostomium 5 Mouth 6 Nerve collar 7 Segmental ganglion 8 Pharynx 9 Esophagus 10 Segmental nerve 11 Crop 12 Gizzard 13 Ventral nerve cord
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Feed on organic matter in soil Digest organic matter
Feeding Feed on organic matter in soil Digest organic matter Wastes and undigested soil eliminated as casting Loosens and aerates soil Digestion Soil sucked in by pharynx -> esophagus -> crop (storage) -> gizzard (grinds soil releasing organic matter) -> intestine (nutrients absorbed) 1 Anus 2 Intestine 3 Cerebral ganglion 4 Prostomium 5 Mouth 6 Nerve collar 7 Segmental ganglion 8 Pharynx 9 Esophagus 10 Segmental nerve 11 Crop 12 Gizzard 13 Ventral nerve cord
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Transport oxygen, nutrients, and wastes
Circulation Transport oxygen, nutrients, and wastes Flow of blood toward posterior via ventral blood vessel Flow of blood toward anterior via dorsal blood vessel 5 pair of aortic arches link vessels near anterior Smaller vessels branch into segments Contraction of ventral vessel and aortic arches forces blood through body 1 Anus 2 Dorso-subneural vessel 3 Intestine 4 Dorsal vessel 5 Hearts (aortic arches) 6 Mouth 7 Ventral vessel 8 Subneural vessel
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Lack gills or lungs--oxygen and carbon dioxide diffuse across skin
Gas Exchange Lack gills or lungs--oxygen and carbon dioxide diffuse across skin Requires moist skin, thin cuticle, mucus secretion…limits habitat! Excretion Elimination of nitrogen wastes Long tubules (nephridia) excrete wastes Coelomic fluid enters nephridium through ciliated funnel opening Some water reabsorbed by blood Remaining fluid excreted through ventral pores A External view B Excretory system (nephridium) C-D Reproductive system C Lateral view D Dorsal view 1 Nephrostome 2 Septum 3 Ciliated tube 4 Bladder 5 Nephridiopore 6 Body wall
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Hermaphrodites--cannot self fertilize Worms join head to tail
Reproduction Hermaphrodites--cannot self fertilize Worms join head to tail Form mucus coat around bodies--each inject sperm into mucus Sperm move to seminal receptacle Eggs move through oviducts to female genital pore Clitellum secretes mucus and chitinous sheath Worm wiggles to slip off sheath Eggs and sperm join A External view B Excretory system (nephridium) C-D Reproductive system C Lateral view D Dorsal view 1 Nephrostome 2 Septum 3 Ciliated tube 4 Bladder 5 Nephridiopore 6 Body wall 7 Seminal vesicle 8 Testis 9 Egg sac 10 Male opening 11 Female opening 12 Oviduct 13 Ovary 14 Sperm duct (vas deferens) 15 Opening to sperm-receiving sac 16 Sperm-receiving sac (spermatheca)
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http://biog-101-104. bio. cornell
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Animals probably evolved from a flagellated protist similar to the choanoflagellates
flagellum One step in this evolution is to become colonial. Here are the choanocytes of one of the simplest of sponges. Basically the most primitive animals. collar cell body Of course the other required step is to eliminate the chloroplasts of the choanoflagellate (Chrysophyta!).
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Evolution of Body Organization
Sponge, Cnidarian spongocoel Planarian gastrovascular cavity Ectoderm Endoderm Mesoderm Nematode pseudocoelom 2-layered 3-layered digestive tract Acoelomate Annelid coelom Pseudocoelomate Coelomate
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Development or Evolution?
cleavage zygote blastula 2-layered acoelomate body plan
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Origin of Mesoderm Cnidarians Protostome Phyla Deuterostome Phyla
Platyhelminthes Nematoda Annelida Mollusca Arthropoda Origin of Mesoderm Cnidarians Echinodermata Hemichordata Chordata Protostome Phyla blastocoel archenteron Deuterostome Phyla (except vertebrates) blastopore mouth mouth anus
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The Animal Clade Extant
Platyhelminthes acoelomates Arthropoda Annelida Mollusca protostomia Nematoda Rotifera pseudo-coelomates Hemichordata Echinodermata Porifera parazoa Cnidaria Chordata deuterostomia coelomates radiata This cladogram omits several smaller animal phyla! bilateria eumetazoa (true tissues) loss of chloroplast, colonial organization Ancestral Choanoflagellate
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