DOCSLIB.ORG

COELOME Introduction Evolution of Body Cavity Is an Important Event

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
COELOME Introduction Evolution of Body Cavity Is an Important Event COELOME Introduction Evolution of body cavity is an important event which further helped the formation of efficient body systems to support growing organs and distribute material. Body cavity also acts as shock absorber and protects the internal organs. Coelome is the main body cavity in most of the animals which is located between the intestinal canal and the body wall. Early stages of development In general, zygote undergoes rapid cell divisions called as cleavage to produce a compact mass of cells called morula. The different cells derived from the cleavage are called as blastomeres. Cleavage ends with the formation of blastula. As the cleavage proceeds, the number of blastomeres increases and cells of blastula are arranged into a hollow ball like structure. The central cavity of blastula is called as blastocoel or segmentation cavity or primary body cavity. Invagination of the cells at one end of the blastula results in the formation of Gastrula. The open cavity of gastrula lined by endoderm is called archenteron or primitive gut. Its opening is called as blastopore. The outer layer of gastrula is the ectoderm and the inner layer is called as endoderm. And the cavity between the two layers is blastocoel. Members of radiata are diploblastic with ectoderm and endoderm. But bilaterians are triploblastic with a third germ layer called mesoderm which arises between ectoderm and endoderm. Mesoderm is solid but has loosely organized tissue called mesenchyme. 1. In aceolomates, blastocoel is completely occupied by mesenchyme. 2. In pseudocoelomate, blastocoel is partly filled by mesenchyme and the unoccupied portion exists as pseudocoelom. 3. In coelomates, blastocoel is completely replaced by true coelom. Definition of coelom Coelome in Greek language means a hollow cavity. It is a fluid-filled cavity between alimentary canal and body wall. It is lined on all sides by mesoderm. The peritoneal cavity of INVERTEBRATA NOTES –M.Sc. ZOOLOGY(Previous)- Dr.C.V.Narasimha murthy, Associate Professor(CONTRACT)-VSUPG CENTRE-KAVALI. 2018. abdomen is also a part of coelom and there are similar spaces around our heart and lungs. The structure and mode of development of coelom differs among different group of animals. Advantages of coelom Primitive diploblastic and triploblastic animals have developed only one major body cavity called as the digestive tract. This digestive tract gave many limitations on the body size, development and locomotion of the animals. With the increasing body size, the weight of the animal also increases. This increased body mass puts lot of stress on the body organs during locomotion thereby preventing the formation of effective circulatory system. All these reasons paved way for the evolution of animals by the development of additional body cavity called as the coelom. The advantages of the coelom are as follows: 1. The organs like that of the digestive tract need more space to grow. Coelome allows this extra space for such organs. 2. Some organs like gonads need more space only during the breeding season. Some animals which give birth to young ones need more space only during certain stage of their life. This space is arranged by the coelom. 3. Coelome also allows the formation of well-organized circulatory system with an efficient heart to draw blood from vessels. 4. Coelomic fluid transports materials faster than diffusion. Generally animals fill food or waste products into the coelom. These products are distributed as required. 5. Coelomic fluid generates effective hydrostatic force against which the muscles of the animals act. Types of animals based on coelom There are three structural types of body plans related to the coelom. 1. Acoelomates (animals with no coelom) 2. Pseudocoelomates (animals with false coelom) 3. Eucoelomates (animals with true coelom) Additionally two other types of structural body plans can be observed namely, schizocoelomates and enterocoelomates mainly in higher grade animals. These two are based on the mode of formation of the coelom. Acoelomates Acoelomates have no coelomic cavity. The space around the internal organs is completely filled by parenchyma. Hence there is no body cavity surrounding the internal organs. Parenchyma restricts the movement of the internal organs. Only a gut, coelenterons or spongocoel exists in these animals and there is no other cavity. Ex: flatworms (platyhelminthes), coelenterates and sponges. INVERTEBRATA NOTES –M.Sc. ZOOLOGY(Previous)- Dr.C.V.Narasimha murthy, Associate Professor(CONTRACT)-VSUPG CENTRE-KAVALI. 2018. Pseudocoelomates As it is neither formed in mesoderm nor it is lined by mesodermal peritoneum it is called so. The internal organs lie freely within pseudocoelom. Ex: round worms (nemathelminthes) and some minor phyla grouped under aschelminthes. Coelomates or Eucoelomates They are true coelomates in which the coelom is lined both inside the body wall and around the gut by mesoderm. The coelom is lined by the mesodermal epithelium called as peritoneum. The portion of the epithelium that lines the outer wall of coelom is called as parietal/somatic peritoneum. The portion of the epithelium that lines the inner wall of coelom is called as visceral/splanchnic epithelium. Animals with a true coelom also have mesenteries, which suspend the body organs within the coelom. Ex: annelids, arthropods, molluscs, echinoderms and chordates Types of coelomates Based on the mode of formation of coelom, coelomates are classified into the following types: A) Schizocoelomates They are true coelomates in which the body cavity originates by splitting of mesodermal tissue at the time of gastrulation. This method of coelom formation is called schizocoelous (gr. Schizo = split), and occurs in animals like annelids, arthropods and molluscs. Sometimes the schizocoelomates is filled with blood and is called haemocoel as in arthropods and molluscs. A) Schizocoelomates They are true coelomates in which the body cavity originates by splitting of mesodermal tissue at the time of gastrulation. This method of coelom formation is called INVERTEBRATA NOTES –M.Sc. ZOOLOGY(Previous)- Dr.C.V.Narasimha murthy, Associate Professor(CONTRACT)-VSUPG CENTRE-KAVALI. 2018. schizocoelous (gr. Schizo = split), and occurs in animals like annelids, arthropods and molluscs. Sometimes the schizocoelomates is filled with blood and is called haemocoel as in arthropods and molluscs. B) Enterocoelomates In most deuterostomes, such as chordates and echinoderms, the coelom originates by out- pouching of the archenteron during gastrulation. Each pouch then expands and its mesoderm lines the gut on the inner side and body wall on the outer side. This method of coelom formation is called enterocoelous. INVERTEBRATA NOTES –M.Sc. ZOOLOGY(Previous)- Dr.C.V.Narasimha murthy, Associate Professor(CONTRACT)-VSUPG CENTRE-KAVALI. 2018. .
Load more

Recommended publications
  • Cleavage of Cytoskeletal Proteins by Caspases During Ovarian Cell Death: Evidence That Cell-Free Systems Do Not Always Mimic Apoptotic Events in Intact Cells
    Cell Death and Differentiation (1997) 4, 707 ± 712 1997 Stockton Press All rights reserved 13509047/97 $12.00 Cleavage of cytoskeletal proteins by caspases during ovarian cell death: evidence that cell-free systems do not always mimic apoptotic events in intact cells Daniel V. Maravei1, Alexander M. Trbovich1, Gloria I. Perez1, versus the cell-free extract assays (actin cleaved) raises Kim I. Tilly1, David Banach2, Robert V. Talanian2, concern over previous conclusions drawn related to the Winnie W. Wong2 and Jonathan L. Tilly1,3 role of actin cleavage in apoptosis. 1 The Vincent Center for Reproductive Biology, Department of Obstetrics and Keywords: apoptosis; caspase; ICE; CPP32; actin; fodrin; Gynecology, Massachusetts General Hospital/Harvard Medical School, proteolysis; granulosa cell; follicle; atresia Boston, Massachusetts 02114 USA 2 Department of Biochemistry, BASF Bioresearch Corporation, Worcester, Massachusetts 01605 USA Abbreviations: caspase, cysteine aspartic acid-speci®c 3 corresponding author: Jonathan L. Tilly, Ph.D., Massachusetts General protease (CASP, designation of the gene); ICE, interleukin- Hospital, VBK137E-GYN, 55 Fruit Street, Boston, Massachusetts 1b-converting enzyme; zVAD-FMK, benzyloxycarbonyl-Val- 02114-2696 USA. tel: +617 724 2182; fax: +617 726 7548; Ala-Asp-¯uoromethylketone; zDEVD-FMK, benzyloxycarbo- e-mail: [email protected] nyl-Asp-Glu-Val-Asp-¯uoromethylketone; kDa, kilodaltons; Received 28.1.97; revised 24.4.97; accepted 14.7.97 ICH-1, ICE/CED-3 homolog-1; CPP32, cysteine protease Edited by J.C. Reed p32; PARP, poly(ADP-ribose)-polymerase; MW, molecular weight; STSP, staurosporine; C8-CER, C8-ceramide; DTT, dithiothrietol; cCG, equine chorionic gonadotropin (PMSG or Abstract pregnant mare's serum gonadotropin); ddATP, dideoxy-ATP; kb, kilobases; HEPES, N-(2-hydroxyethyl)piperazine-N'-(2- Several lines of evidence support a role for protease ethanesulfonic acid); SDS ± PAGE, sodium dodecylsulfate- activation during apoptosis.
    [Show full text]
  • Animal Origins and the Evolution of Body Plans 621
    Animal Origins and the Evolution 32 of Body Plans In 1822, nearly forty years before Darwin wrote The Origin of Species, a French naturalist, Étienne Geoffroy Saint-Hilaire, was examining a lob- ster. He noticed that when he turned the lobster upside down and viewed it with its ventral surface up, its central nervous system was located above its digestive tract, which in turn was located above its heart—the same relative positions these systems have in mammals when viewed dorsally. His observations led Geoffroy to conclude that the differences between arthropods (such as lobsters) and vertebrates (such as mammals) could be explained if the embryos of one of those groups were inverted during development. Geoffroy’s suggestion was regarded as preposterous at the time and was largely dismissed until recently. However, the discovery of two genes that influence a sys- tem of extracellular signals involved in development has lent new support to Geof- froy’s seemingly outrageous hypothesis. Genes that Control Development A A vertebrate gene called chordin helps to establish cells on one side of the embryo human and a lobster carry similar genes that control the development of the body as dorsal and on the other as ventral. A probably homologous gene in fruit flies, called axis, but these genes position their body sog, acts in a similar manner, but has the opposite effect. Fly cells where sog is active systems inversely. A lobster’s nervous sys- become ventral, whereas vertebrate cells where chordin is active become dorsal. How- tem runs up its ventral (belly) surface, whereas a vertebrate’s runs down its dorsal ever, when sog mRNA is injected into an embryo (back) surface.
    [Show full text]
  • Animal Phylum Poster Porifera
    Phylum PORIFERA CNIDARIA PLATYHELMINTHES ANNELIDA MOLLUSCA ECHINODERMATA ARTHROPODA CHORDATA Hexactinellida -- glass (siliceous) Anthozoa -- corals and sea Turbellaria -- free-living or symbiotic Polychaetes -- segmented Gastopods -- snails and slugs Asteroidea -- starfish Trilobitomorpha -- tribolites (extinct) Urochordata -- tunicates Groups sponges anemones flatworms (Dugusia) bristleworms Bivalves -- clams, scallops, mussels Echinoidea -- sea urchins, sand Chelicerata Cephalochordata -- lancelets (organisms studied in detail in Demospongia -- spongin or Hydrazoa -- hydras, some corals Trematoda -- flukes (parasitic) Oligochaetes -- earthworms (Lumbricus) Cephalopods -- squid, octopus, dollars Arachnida -- spiders, scorpions Mixini -- hagfish siliceous sponges Xiphosura -- horseshoe crabs Bio1AL are underlined) Cubozoa -- box jellyfish, sea wasps Cestoda -- tapeworms (parasitic) Hirudinea -- leeches nautilus Holothuroidea -- sea cucumbers Petromyzontida -- lamprey Mandibulata Calcarea -- calcareous sponges Scyphozoa -- jellyfish, sea nettles Monogenea -- parasitic flatworms Polyplacophora -- chitons Ophiuroidea -- brittle stars Chondrichtyes -- sharks, skates Crustacea -- crustaceans (shrimp, crayfish Scleropongiae -- coralline or Crinoidea -- sea lily, feather stars Actinipterygia -- ray-finned fish tropical reef sponges Hexapoda -- insects (cockroach, fruit fly) Sarcopterygia -- lobed-finned fish Myriapoda Amphibia (frog, newt) Chilopoda -- centipedes Diplopoda -- millipedes Reptilia (snake, turtle) Aves (chicken, hummingbird) Mammalia
    [Show full text]
  • Animal Kingdom
    ANIMAL KINGDOM Characteristics of Animals Heterotrophic Can’t make their own food Mobile Multicellular Diploid cells Sexual reproduction No cell wall Blastula Fertilized egg cell divides to form a hollow ball of cells Forms 3 layers – ectoderm, endoderm, mesoderm Tissues Group of cells with a common function Characteristics of Animals Body symmetry Asymmetrical – irregular in shape Ex: sponges Radial symmetry – body parts around a central axis Ex: sea anemone Bilateral symmetry – distinct right and left halves Characteristics of Animals Internal body cavity Coelom – fluid-filled space between the body wall and digestive tract Acoelomates – animal with no body cavity Pseudocoelomates – “false coelom” Located between mesoderm and endoderm Coelomates – body cavity located entirely in the mesoderm Kinds of Animals Divided into two groups Invertebrates Animals without a backbone Vertebrates Animals with a backbone Invertebrates Sponges Cnidarians Flatworms and Roundworms SPONGES Phylum – Porifera Asymmetrical body form Not organized into tissues and organs Ostia – openings in the body wall Where water enters the sponge Oscula – large openings Where water exits the sponge Sessile – attached to the sea bottom or a rock or coral reef and don’t move from that place Filter feeders Can reproduce sexually or asexually CNIDARIANS What kinds of animals are these??? Jellyfish, sea anemones 2 different body forms Medusa – free-floating, jellylike, often shaped like an umbrella Polyp – tubelike and usually
    [Show full text]
  • Understanding Paraxial Mesoderm Development and Sclerotome Specification for Skeletal Repair Shoichiro Tani 1,2, Ung-Il Chung2,3, Shinsuke Ohba4 and Hironori Hojo2,3
    Tani et al. Experimental & Molecular Medicine (2020) 52:1166–1177 https://doi.org/10.1038/s12276-020-0482-1 Experimental & Molecular Medicine REVIEW ARTICLE Open Access Understanding paraxial mesoderm development and sclerotome specification for skeletal repair Shoichiro Tani 1,2, Ung-il Chung2,3, Shinsuke Ohba4 and Hironori Hojo2,3 Abstract Pluripotent stem cells (PSCs) are attractive regenerative therapy tools for skeletal tissues. However, a deep understanding of skeletal development is required in order to model this development with PSCs, and for the application of PSCs in clinical settings. Skeletal tissues originate from three types of cell populations: the paraxial mesoderm, lateral plate mesoderm, and neural crest. The paraxial mesoderm gives rise to the sclerotome mainly through somitogenesis. In this process, key developmental processes, including initiation of the segmentation clock, formation of the determination front, and the mesenchymal–epithelial transition, are sequentially coordinated. The sclerotome further forms vertebral columns and contributes to various other tissues, such as tendons, vessels (including the dorsal aorta), and even meninges. To understand the molecular mechanisms underlying these developmental processes, extensive studies have been conducted. These studies have demonstrated that a gradient of activities involving multiple signaling pathways specify the embryonic axis and induce cell-type-specific master transcription factors in a spatiotemporal manner. Moreover, applying the knowledge of mesoderm development, researchers have attempted to recapitulate the in vivo development processes in in vitro settings, using mouse and human PSCs. In this review, we summarize the state-of-the-art understanding of mesoderm development and in vitro modeling of mesoderm development using PSCs. We also discuss future perspectives on the use of PSCs to generate skeletal tissues for basic research and clinical applications.
    [Show full text]
  • Introduction to Phylum Chordata
    Unifying Themes 1. Chordate evolution is a history of innovations that is built upon major invertebrate traits •bilateral symmetry •cephalization •segmentation •coelom or "gut" tube 2. Chordate evolution is marked by physical and behavioral specializations • For example the forelimb of mammals has a wide range of structural variation, specialized by natural selection 3. Evolutionary innovations and specializations led to adaptive radiations - the development of a variety of forms from a single ancestral group Characteristics of the Chordates 1. Notochord 2. dorsal hollow nerve cord 3. pharyngeal gill slits 4. postanal tail 5. endostyle Characteristics of the Chordates Notochord •stiff, flexible rod, provides internal support • Remains throughout the life of most invertebrate chordates • only in the embryos of vertebrate chordates Characteristics of the Chordates cont. Dorsal Hollow Nerve Cord (Spinal Cord) •fluid-filled tube of nerve tissue, runs the length of the animal, just dorsal to the notochord • Present in chordates throughout embryonic and adult life Characteristics of the Chordates cont. Pharyngeal gill slits • Pairs of opening through the pharynx • Invertebrate chordates use them to filter food •In fishes the gill sits develop into true gills • In reptiles, birds, and mammals the gill slits are vestiges (occurring only in the embryo) Characteristics of the Chordates cont. Endostyle • mucous secreting structure found in the pharynx floor (traps small food particles) Characteristics of the Chordates cont. Postanal Tail • works with muscles (myomeres) & notochord to provide motility & stability • Aids in propulsion in nonvertebrates & fish but vestigial in later lineages SubPhylum Urochordata Ex: tunicates or sea squirts • Sessile as adults, but motile during the larval stages • Possess all 5 chordate characteristics as larvae • Settle head first on hard substrates and undergo a dramatic metamorphosis • tail, notochord, muscle segments, and nerve cord disappear SubPhylum Urochordata cont.
    [Show full text]
  • Vertebrate Embryonic Cleavage Pattern Determination
    Chapter 4 Vertebrate Embryonic Cleavage Pattern Determination Andrew Hasley, Shawn Chavez, Michael Danilchik, Martin Wühr, and Francisco Pelegri Abstract The pattern of the earliest cell divisions in a vertebrate embryo lays the groundwork for later developmental events such as gastrulation, organogenesis, and overall body plan establishment. Understanding these early cleavage patterns and the mechanisms that create them is thus crucial for the study of vertebrate develop- ment. This chapter describes the early cleavage stages for species representing ray- finned fish, amphibians, birds, reptiles, mammals, and proto-vertebrate ascidians and summarizes current understanding of the mechanisms that govern these pat- terns. The nearly universal influence of cell shape on orientation and positioning of spindles and cleavage furrows and the mechanisms that mediate this influence are discussed. We discuss in particular models of aster and spindle centering and orien- tation in large embryonic blastomeres that rely on asymmetric internal pulling forces generated by the cleavage furrow for the previous cell cycle. Also explored are mechanisms that integrate cell division given the limited supply of cellular building blocks in the egg and several-fold changes of cell size during early devel- opment, as well as cytoskeletal specializations specific to early blastomeres A. Hasley • F. Pelegri (*) Laboratory of Genetics, University of Wisconsin—Madison, Genetics/Biotech Addition, Room 2424, 425-G Henry Mall, Madison, WI 53706, USA e-mail: [email protected] S. Chavez Division of Reproductive & Developmental Sciences, Oregon National Primate Research Center, Department of Physiology & Pharmacology, Oregon Heath & Science University, 505 NW 185th Avenue, Beaverton, OR 97006, USA Division of Reproductive & Developmental Sciences, Oregon National Primate Research Center, Department of Obstetrics & Gynecology, Oregon Heath & Science University, 505 NW 185th Avenue, Beaverton, OR 97006, USA M.
    [Show full text]
  • Human Anatomy Bio 11 Embryology “Chapter 3”
    Human Anatomy Bio 11 Embryology “chapter 3” Stages of development 1. “Pre-” really early embryonic period: fertilization (egg + sperm) forms the zygote gastrulation [~ first 3 weeks] 2. Embryonic period: neurulation organ formation [~ weeks 3-8] 3. Fetal period: growth and maturation [week 8 – birth ~ 40 weeks] Human life cycle MEIOSIS • compare to mitosis • disjunction & non-disjunction – aneuploidy e.g. Down syndrome = trisomy 21 • visit http://www.ivc.edu/faculty/kschmeidler/Pages /sc-mitosis-meiosis.pdf • and/or http://www.ivc.edu/faculty/kschmeidler/Pages /HumGen/mit-meiosis.pdf GAMETOGENESIS We will discuss, a bit, at the end of the semester. For now, suffice to say that mature males produce sperm and mature females produce ova (ovum; egg) all of which are gametes Gametes are haploid which means that each gamete contains half the full portion of DNA, compared to somatic cells = all the rest of our cells Fertilization restores the diploid state. Early embryonic stages blastocyst (blastula) 6 days of human embryo development http://www.sisuhospital.org/FET.php human early embryo development https://opentextbc.ca/anatomyandphysiology/chapter/28- 2-embryonic-development/ https://embryology.med.unsw.edu.au/embryology/images/thumb/d/dd/Model_human_blastocyst_development.jpg/600px-Model_human_blastocyst_development.jpg Good Sites To Visit • Schmeidler: http://www.ivc.edu/faculty/kschmeidler/Pages /sc_EMBRY-DEV.pdf • https://embryology.med.unsw.edu.au/embryol ogy/index.php/Week_1 • https://opentextbc.ca/anatomyandphysiology/c hapter/28-2-embryonic-development/
    [Show full text]
  • Cleavage: Types and Patterns Fertilization …………..Cleavage
    Cleavage: Types and Patterns Fertilization …………..Cleavage • The transition from fertilization to cleavage is caused by the activation of mitosis promoting factor (MPF). Cleavage • Cleavage, a series of mitotic divisions whereby the enormous volume of egg cytoplasm is divided into numerous smaller, nucleated cells. • These cleavage-stage cells are called blastomeres. • In most species the rate of cell division and the placement of the blastomeres with respect to one another is completely under the control of the proteins and mRNAs stored in the oocyte by the mother. • During cleavage, however, cytoplasmic volume does not increase. Rather, the enormous volume of zygote cytoplasm is divided into increasingly smaller cells. • One consequence of this rapid cell division is that the ratio of cytoplasmic to nuclear volume gets increasingly smaller as cleavage progresses. • This decrease in the cytoplasmic to nuclear volume ratio is crucial in timing the activation of certain genes. • For example, in the frog Xenopus laevis, transcription of new messages is not activated until after 12 divisions. At that time, the rate of cleavage decreases, the blastomeres become motile, and nuclear genes begin to be transcribed. This stage is called the mid- blastula transition. • Thus, cleavage begins soon after fertilization and ends shortly after the stage when the embryo achieves a new balance between nucleus and cytoplasm. Cleavage Embryonic development Cleavage 2 • Division of first cell to many within ball of same volume (morula) is followed by hollowing
    [Show full text]
  • Andivers2'06h.O.Pdf
    Animal diversity 2 - Animals Mapping body plan characters without a coelom on the tree Key concepts PROTOSTOMES ARTHROPODA DEUTEROSTOMES NEMATODA • Simple animals may be ANNELIDA MOLLUSCA evolutionarily successful, have PLATYHELMINTHES CNIDARIA RADIAL SYMMETRY diverse life styles and behavior! MOUTH PORIFERA ECHINODERMATA • Basic biology of CHORDATA Porifera/ Cnidaria/ AND Platyhelminthes/ Nematoda ANUS TRUE COELOM MOUTH AND ANUS BILATERAL SYMMETRY TISSUES 1 EXTRACELLULAR DIGESTION 2 PROTISTAMULTICELLULARITY Today: phyla without a true coelom Diversity of Sponges PROTOSTOMES A. Body plan - ARTHROPODA DEUTEROSTOMES NEMATODA cells in ANNELIDA MOLLUSCA extracellular PLATYHELMINTHES CNIDARIA matrix, tube RADIAL SYMMETRY MOUTH PORIFERA ECHINODERMATA structure CHORDATA AND with flow of water ANUS TRUE COELOM bringing MOUTH AND ANUS food to cells BILATERAL SYMMETRY TISSUES EXTRACELLULAR DIGESTION 3 PROTISTAMULTICELLULARITY 4 B. Feeding If choanocytes specialized for Diversity of Sponges feeding, how are other cell types nourished? C. Reproduction via another cell type Asexual - branches may ‘pinch’ off and - amoeboid cells regenerate that move Sexual - most are hermaphrodites throughout the Hermaphrodite - single individual produces sponge, collecting both male and female gametes and further digesting material from choanocytes, then passing it on to other cells... 5 6 Page ‹#› Diversity of Sponges Diversity of Sponges Sperm are produced from modified The zygote (fertilized choanocytes, released egg) gives into the environment rise to swimming
    [Show full text]
  • Organogenesis Part 2 ______
    Organogenesis Part 2 ___________________________________ ___________________________________ V. Lateral Plate Mesoderm VI. Endoderm ___________________________________ VII. Development of the Tetrapod Limb VIII. Sex Determination ___________________________________ ___________________________________ ___________________________________ ___________________________________ V. Lateral Plate Mesoderm ___________________________________ ___________________________________ paraxial mesoderm chordamesoderm intermediate mesoderm ___________________________________ ___________________________________ ___________________________________ lateral plate mesoderm ___________________________________ ___________________________________ Lateral Plate Mesoderm ___________________________________ Terminology: - Somatopleure: somatic mesoderm plus ectoderm ___________________________________ - Splanchnopleure: splanchnic mesoderm plus endoderm - Coelom: body cavity forms between them ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ Lateral Plate Mesoderm ___________________________________ • The Coelom: ___________________________________ – eventually left and right cavities fuse into one ___________________________________ – runs from neck to anus in vertebrates – portioned off by folds of somatic mesoderm ___________________________________ • pleural cavity: surrounds the thorax and lungs • pericardial cavity: surrounds the
    [Show full text]
  • BI 101: Invertebrate Animals
    5/30/2014 BI 101: Invertebrate Animals Hornwort- a bryophyte 1 5/30/2014 Announcements • Lab tomorrow: Invertebrates ( lab worksheet provided) – No prelab • Extra credit: Mycorestoration at Sequoia creek – Friday June 6th, 2014 3-4pm – the street Coffee culture, Corvallis • Extra credit: World Oceans Day- beach cleanup – Sunday June 8th – Nye Beach, Newport Classification The three-domains Bacteria Archaea Eukarya The six-kingdom system Bacteria Archaea Protista Plantae Fungi Animalia The traditional five-kingdom system Monera Protista Plantae Fungi Animalia 2 5/30/2014 (Forams and Radiolarians) Rhizarians Alveolates Rhodophyta Stramenopile CHLOROPHYTA Euglenozoa AMOEBOZOANS What are some characteristics animals share? List as many as you can think of. Discuss this in your groups 3 5/30/2014 Animal Cell Fungus Cell Evidence indicates that animals evolved from choanoflagellates (protists) ~ 570 mya • Single cells • Often clonal • Heterotroph • No specialization or coodination between cells 4 5/30/2014 Animal Classification 1. DNA sequencing 2. Body Symmetry 3. Presence or absence of body cavity 4. Embyonic Development Symmetry 5 5/30/2014 Body Cavity Most bilateral animals have body cavities – Body cavities are fluid-filled cavities between the digestive tube and the outer body wall – Functions: • skeleton, providing support for the body and a framework against which muscles can act • protective buffer between the internal organs and the outside world • They can allow organs to move independently of the body wall Body Cavity? epidermis gut cavity organs packed between A No coelom gut and body wall (acoelomate animal) Fig. 25-4a, p. 405 6 5/30/2014 Body Cavity? epidermis gut cavity B Pseudocoel (pseudocoelomate animal) unlined body cavity around gut Fig.
    [Show full text]