Study Guides (247,997)
Canada (121,215)
Biology (1,267)
BIO2135 (155)

BIO2135 Final: Animal Form and Function Final Review - Keywords

22 Pages
Unlock Document

Jon Houseman

Protozoa 9+2 organization: The arrangement of microtubules in cilia and flagella; 2 central tubulin fibers surrounded by 9 peripheral tubules that facilitates movement of the cilia or flagella when dyein arms attach as molecular motors Actin: A protein found in all eukaryotic cells, forming filaments that make up the cell’s structural matrix or cytoskeleton; actin and myosin make up contractile units called sarcomeres Amoebozoa: A major taxonomic group containing thousands of amoeboid species; defined as possessing blunt, finger-like, lobose pseudopods; a large phylum in the Protista/Protozoa kingdom Apicomplexa: A large phylum of parasitic alveolates; these parasitic organisms possess an apical complex structure which facilitates penetration of host cells Archaeplastida: A supergroup of protists (including red and green algae); evolved from endosymbiotic relationships between a heterotrophic protist and a cyanobacteria; Asexual reproduction: A form of reproduction that does not involve meiosis, ploidy reduction or fertilization; the offspring is a clone of the parent as no genetic material is exchanged; binary fission and multiple fission (schizogony) Alveolate: Defined by the presence of an alveolus beneath the cell membrane and include dinoflagellates, apicomplexans and ciliates Basal body: Structure at the base of cilia and flagella from which microtubules forming the axoneme radiate; structurally similar to a centriole Bikont: A eukaryotic cell with two flagella Binary fission: Asexual reproduction; cell division where the parent cell divides into two daughter cells of equal size Cellular creeping (gliding): A process whereby an organism can move across a substrate without the use of a flagella Centriole: A small cylindrical organelle near the nucleus in animal cells which is involved in the development of spindle fibers in cell division Centrosome: An organelle near the nucleus of a cell that contains centrioles, which develop spindle fibers Choanocyte: This unique collar-shaped cells whose flagella are responsible for generating the water current in the sponge. As the flagella beat, food particles are trapped against the microvilli that form the collar. Choanocytes are also found in some colonial protists Chromalveolata: A eukaryote supergroup present in the Protista/protozoa kingdom; they are defined by the presence of alveolus (small sacs underlining the cell) and colour pigments Cilia: Cellular hairlike locomotory structures that consists of an extension of the plasma membrane surrounding a 9+2 organization of microtubules. Unlike flagella, cilia are shorter and more numerous on the cell surface Ciliophora: A group of protozoans characterized by the presence of hair-like organelles called cilia that are similar to flagella in structure but are shorter and present in larger quantities Cirrus: Slender filamentous structures: fused cilia in protozoa, attachment appendages in sessile echinoderms, or a copulatory organ found in some invertebrates Colonial choanoflagellate: Free-living protozoans that exist in colonies Conjugation: Sexual reproduction; one organism transfers genetic material to another through direct contact Contractile vacuoles: A membrane-enveloped cellular organelle that fills with water then contracts, expelling the contains from the cell Cytopharynx: An organelle in certain flagellates and ciliates that serves as a gullet through which food material passes from the cytostome to the cell interior Cytoplasmic streaming: The movement of the cytoplasm within an organism to transport nutrients, proteins and organelles around the cell Cytoproct: The anal opening in a unicellular organism Cytostome: In some protozoans, especially ciliates, phagocytosis always occurs at the same position on the cell surface. When this occurs the location is referred to as the cytostome (cell mouth) Dyenin arm: A structure that attaches to the microtubule structures to facilitate movement Dyenin motor: The dynein arm moves along the microtubule; converting ATP to mechanical work and moving the flagella/cilia, propelling the cell to move Ectoplasm: The outer cytoplasm of a cell or protozoan that has no organelles; usually less fluid than the inner endoplasm Endomembrane system: A system composed of different membranes that are suspended in the cytoplasm; divide the cell into functional and structural components and organelles Endoplasm: The inner cytoplasm of a cell or protozoan with organelles; usually more fluid than the outer ectoplasm Endosymbiont theory: Explains how eukaryotes may have evolved from prokaryotes; a single-celled organism engulfs another  accounts for the nuclear envelop, intracellular membrane and spaces Euglenozoa: A large group of flagellate excavates; include a variety of free-living species and important parasites that infect humans; long, cylindrical bodies with flagella; asexual reproduction; include euglena Excavata: A supergroup of protists defined by an asymmetrical appearance with a feeding groove Eye spot: Simple type of eye found in invertebrates; consisting of photoreceptive cells positioned underneath a lens that can either change its shape or be positioned to focus light; May be image-forming on some (nautilus and spiders), or it may only detect light intensities Flagella: A cellular hairlike locomotory structure that consists of an extension of the plasma membrane surrounding a 9+2 organization of microtubules. Unlike cilia, flagella are longer and are usually found singly or in pairs on each cell Food vacuole: A vacuole containing digestive enzymes that break down food Gametocyte: A cell capable of dividing to produce gametes; can undergo meiosis to produce four similar gametes Gametogony: The life stage of a sporozoan in which gametes are formed Helicoid flagellar beat: flagellum movement is spiral Hyaline cap: When a pseudopodium begins to form, a clear space at the leading edge of the pseudopodium called the hyaline cap appears. After this occurs, endoplasm begins to flow into this space, causing the pseudopodium to be pushed forward through the medium Kinesin Motor: Protein that walks towards + end of microtubule. Powered by hydrolysis of ATP Kinetodesmata: Longitudinally oriented cytoplasmic fibrils associated with and always on the right of, the kinetosomes of ciliates Lobose pseudopod: Group of amoebozoa. Lobose psudopods are blunt, and there may be one or several on a cell, which is usually divided into a layer of clear ectoplasm surrounding more granular endoplasm Lysosome: Organelles containing a large range of digetive enzymes used primarily for digestion and removal of excess or worn-out organelles, food particles, and engulfed viruses or bacteria Macronucleus: one of two types of dimporphic nuclei found in ciliate protozoans. The macronucleus contains multiple copies of the genome (polyploidy) and is responsible for general protozoan cell function. The other type of nucleus is the micronucleus Membranelle: are structures found around the mouth, or cytostome, in ciliate protists. They are typically arranged in series, to form an "adoral zone of membranelles," or AZM, on the left side of the buccal cavity (peristome). The membranelles are made up of kinetosomes arranged in groups to make up polykinetids. The cilia which emerge from these structures appear too fused and to function as a single membrane, which can be used to sweep particles of food into the cytostome, or for locomotion Merozoites: stage in the life cycle of the malaria parasite (plasmodium): formed during the asexual division of the schizont. Merozoites are released and invade other cells Metachronal wave: the synchronized beat along the longitudinal ciliary rows Micronucleus: One of two dimorphic nuclei found in ciliate protozoans; the single micronucleus contains only one copy of the genome and is used during the reproductive cell Microtubules: a hollow cylindrical in the cytoplasm of most cells, involved in intracellular shape and transport Microvilli: Any of the minute hairlike structures projecting from the exposed surface of the cell in order to increase the surface area for absorption, secretion, cellular adhesion, or mechanotransduction Multiple fission: Division of the nucleus, simultaneously or successively, into a number of daughter nuclei, followed by division of the cell body into an equal number of parts, each containing a nucleus Myonemes: strands of contractile myofibers found in single cells. These allow the cell, or a portion of the cell, to contract in length and change its shape Myosin motor: ATP-dependent motor protein, responsible for actin-based motility. Most myosin molecules are composed of a head, neck, and tail domain Nuclear envelope: the double-layered membrane that envelopes the nucleus of a eukaryotic cell, separating the contents of the nucleus from the cytoplasm Oocyst: the encysted zygotic stage in life cycle of some sporozoans Opisthokont: broad group of eukaryotes including both the animal and fungus kingdom together with the eukaryotic microorganism that are sometimes grouped in the paraphletic phylum choanozoa Pellicle: The network of semi-rigid cell membrane thickenings found on the surface of some protozoans. These are used to anchor either the locomotory flagella or cilia into the surrounding plasma membrane Phagocytosis: Cellular ingestion; engulfing food particle or foreign bodies by surrounding them with cytoplasm and forming a membrane-bound vesicle or vacuole containing the particle Phagosome: is a vesicle formed around a particle absorbed by phagocytosis. The vacuole is formed by the fusion of the cell membrane around the particle. A phagosome is a cellular compartment in which pathogenic microorganisms can be killed and digested. Phagosomes fuse with lysosomes in their maturation process, forming phagolysosomes Pinocytosis: uptake of fluid, rather than particulate material, by endocytosis, surrounds the fluid with cytoplasm to form a vesicle or vacuole Planar flagellar beat: Flagellum beats in one plane, so it needs more than one to move in different directions Protista: Kingdom of the taxonomy tree, containing Protists Protozoa: Single-celled organisms, in the kingdom Protista, that exhibit the animal-like characteristics of having to feed to obtain nutrients. They are considered heterotrophic Pseudopod: A cytoplasmic extension that extends from the surface of either a protozoan or any amoeboid cell. These structures are temporary and are used for locomotion and feeding Radiozoa: Phylum of protists; produce intricate mineral skeletons, typically with a central capsule dividing the cell into the inner and outer portions of endoplasm and ectoplasm. They are found as zooplankton throughout the ocean, and their skeletal remains make up a large part of the cover of the ocean floor as siliceous ooze. Due to their rapid turn-over of species, they represent an important diagnostic fossil found from the Cambrian onwards Rhizaria: a species rich supergroup of mostly unicellular eukaryotes that for the most part are amoeboids with filose, reticulose, or microtubule-supported pseudopods Schizogony: A form of asexual reproduction found in some protozoans. An already multinucleated cell undergoes cell division that results in each daughter cell containing only one of the many nuclei present in the parent cell. This is also referred to as multiple fission Sexual reproduction: a mode of reproduction involving the fusion of female gamete (ovum) and male gamete (spermatozoon) which forms a zygote that potentially develops into genetically distinct offspring Sliding microtubule hypothesis: Cilia and flagella are composed of microtubules arranged in nine pairs around a central pair. This arrangement allows the energy from ATP to be used for changing the shape of the cilium or flagellum to accomplish movement. This is known as the sliding microtubule hypothesis Sporogony: a form of asexual reproduction where the fusion product of the male and female gamete (the zygote) undergoes multiple cell divisions that produce sporozites. Found in animals in the protozoan phylum Apicomplexa Sporozoites: any of the minute undeveloped sporozoans produced by multiple fission of a zygote or spore, especially at the stage just before it infects a new host cell Supergroup: Syngamy: the fusion of gametes resulting in the formation of a zygote, which develops into a new organism Synkaryon: The nucleus of a fertilized egg immediately after male and female nuclei have fused Tests: The hard shell of some spherical marine animals; in radiolarians = silica shells; in foraminifera = secreted calcium salts Trichocysts: flask-shaped structure in the pellicles of some protists used to defend and anchor the organism Trophozoites: the feeding stage of a protozoan (as distinct from reproductive or encysted stages Tubulin: is the protein which makes up microtubules. Microtubules are assembled from dimmers of alpha and beta tubulin. Each of these subunits has three domains Undulipod: generic name for cilia and flagella Unikont: a eukaryotic cell with a single flagellum; thought to be the ancestor of all animals Water expulsion vesicle: special organelle found in protozoan and some parozoans that is involved in osmo- regulation. The organelle collects water from the cytoplasm and then releases it from the cell. Also called contractile vacuole Porifera Aboral side: In radially symmetric animals there is no anterior, posterior, left or right sides to the animals. Instead we refer to the two sides of the animal by the location of the mouth. In this case the side opposite the mouth Amebocyte: move throughout sponges and distribute food, can turn into any cell Animalia: taxonomic kingdom comprising all living or extinct animals Apomorphies: A novel evolutionary trait that is unique to a particular species and all its descendants and which can be used as a defining character for a species or group in phylogenetic terms Aquiferous system: This type of system is found in sponges and consists of the canals and chambers through which water flows. Water is pumped through the system by the choanocytes Archeocyte: Cell capable of a variety of functions or of differentiating into a variety of cell types with different functions. Examples include the wandering amebocytes in the mesohyl of a sponge Asconoid: Of the three different sponge architectures, this is the simplest. It consists of a central choanocyte lined spongocoel that opens to the outside directly through the osculum. Water enters the spongocoel after passing through the dermal pores Assymetric body plan: A body plan where there is no axis of symmetry that runs through the body and creates identical parts Autapomorphies: A distinctive feature, known as a derived trait, that is unique to a given taxon Bilaterally symmetric body: In organisms that are bilaterally symmetric there is only one way that the axis of symmetry can pass through the longitudinal axis and create two identical halves. Budding: A form of asexual reproduction where a small part of the body separates from the parent and develops into a complete organism Cellular grade: Organisms with this type of cellular organization are referred to as the Parazoa. They have distinct cells that function independently of each other even though some cells may take on specialized functions. Groups of cells never work together and function as a tissue Choanocyte: This unique collar-shaped cells whose flagella are responsible for generating the water current in the sponge. As the flagella beat, food particles are trapped against the microvilli that form the collar. Choanocytes are also found in some colonial protists Choanoderm: The layer of choanocyte cells lining the different parts of the aquiferous system in a sponge: in the asconoid architecture, the spongocoel; in syconoid, the radial canals; and in leuconoid sponges, the choanocyte chambers Cladistics: A method for classifying organisms based on primitive and derived characters. The resulting arrangement of organisms reflect evolutionary relationships between the taxa Cladogram: A visual representation of the phylogenetic branching of different animal groups based on cladistics. There is no units or measures to the dimensions of a cladogram Collagen: Tough fibrous protein found in the connective tissue of vertebrates and the cuticles of some invertebrates. The protein is flexible but doesn't stretch or compress Dioecious: Organisms that have the male or female reproductive structures in separate individuals. This is the opposite of monoecious Eukaryote: Cells, or organisms with cells, containing a membrane bound nucleus Fragmentation: A form of sexual reproduction wherein a parent organism breaks into fragments, each capable of growing independently into a new organism Gemmule: A bud of asexually formed freshwater sponge cells resistant to unfavorable conditions; permits the organism to survive adverse conditions Hermaphrodite (Monoecious): Organisms that have, at some time during their life, both male and female reproductive structures. This is the opposite of dioecious Heterotroph: Organisms not capable of converting light into chemical energy. They must consume other organisms or material produced by other organisms to survive. This is a characteristic of all animals Intracellular digestion: The final breakdown of ingested food into components small enough to be absorbed across the cell membrane; occurs inside the cells of the digestive tract. Digestive enzymes may be secreted for initial breakdown of the meal, but phagocytosis ultimately occurs, and nutrients are absorbed across the membrane of the phagosome into the cell Leuconoid: The most complex of the three different sponge architectures. Choanocytes are found in chambers, and there is no spongocoel. Water enters incurrent canals to the prosopyles and exits the chambers through apopyles, then excurrent canals and the osculum Mesohyl: Gelatinous matrix between the two layers of cells in the body wall of the sponge. Contains spicules and amebocytes but is not homologous with mesoderm Metazoa: True multicellular organisms that exhibit all the characteristics of animals. They have cells, tissues, and organs Monophyletic: A group of organisms, including the ancestor to that group, that all share a common evolutionary line of descent Oral side: In radially symmetric animals there is no anterior, posterior, left or right sides to the animal. Instead, we refer to the two sides of the animal by the location of the mouth. In this case the side where the mouth is found Osculum: The opening in all types of sponge architectures that water pumped by the sponge exits Paraphyletic: descended from a common evolutionary ancestor or ancestral group, but not including all the descendant groups Parazoa: Animals organized at the cellular grade. They lack tissues; evidence of this is the absence of a basement membrane or tight cell junctions between the cells. Usually includes Porifera and Placozoa Parsimony: Pinacocyte: Flattened cells that cover the surface of a sponge. Collectively they form the pinacoderm Pinacoderm: Outer layer of pinacocyte cells in a sponge. It is not a tissue, only a layer of cells Plesiomorphies: The ancestral trait state, usually in reference to a derived trait state. A symplesiomorphic trait is also shared with other taxa that have an earlier last common ancestor with the taxa under consideration Polyphyletic: A taxon that includes animals from two or more distinct evolutionary lineages and may not include the ancestor of either Porifera: a phylum of aquatic invertebrate animals that comprises the sponges; "pore bearers" Porocyte: A cell in an asconoid sponge with a hole through its center so that water can enter the sponge Radial canal: Radially symmetric body: When an organism's body parts are arranged around the oral-aboral axis so that any plane passing through this axis results in two identical halves Sclerocyte: The type of cell producing spicules in sponges Sister group: Pair of taxa that are the closest phylogenetic relatives of each other Spicules: Any needlelike structure. This term is most often thought of in conjunction with sponges and refers to the needlelike structures produced by sponge cells that form the supporting skeleton. In Nematodes spicules are used by the male during copulation. Needlelike deposits of the shell in Mollusca are also referred to as spicules Spongin: Collagenlike material that forms the skeletal system of some sponges Spongocoel: The internal cavity of asconoid and syconoid sponges that opens to the outside through the osculum. There is no spongocoel in a leuconoid sponge Syconoid: Of the different sponge architectures, this is intermediate in its complexity. The spongocoel is no longer lined with choanocytes, now located in radial canals that open to the spongocoel through apopyles. Water enters the radial canals through prosopyles and exits through a single osculum Symplesiomorphies: an ancestral character or trait state shared by two or more taxa Synapomorphies: A new and unique character that a group of organisms all share and that defines the lineage or clade Totipotent cells: When a differentiated cell can change into any one of a variety of different specialized cells found in an organism. These changes will result in the cell carrying out new functions Cnideria Acontia: Threadlike defensive organs, composed largely of nettling cells (cnidæ), thrown out of the mouth or special pores of certain Actiniæ when irritated Anthozoa: a class within the phylum Cnidaria. Unlike other cnidarians, anthozoans do not have a medusa stage in their development. Instead, they release sperm and eggs that form a planula, which attaches to some substrate on which the cnidarian grows Biradial symmetry: The organism appears radially symmetric but at least one set of structures is paired. This results in only two planes of symmetry that pass through the oral-aboral axis of the animal Blastula: A stage in the development of multicellular animals in which only one cell layer is present, the blastoderm; the cavity the cells surround is the blastocoel. In eggs with little yolk, the embryo resembles a hollow ball; in eggs with yolk, the appearance varies depending on species Cnidaria: any invertebrate animal, as a hydra, jellyfish, sea anemone, or coral, considered as belonging to the phylum Cnidaria, characterized by the specialized stinging structures in the tentacles surrounding the mouth; a coelenterate Cnidocil: A modified flagellum on the cnidocyte that causes the nematocyst inside to fire. The stimulus involves some sort of chemical cue; touching the cnidocil doesn't fire the nematocyst Cnidocytes: Specialized cells found only in the Cnidaria. When these cells evert, a nematocyst is discharged. The nematocyst may act as a stinger or a sticky thread to entangle and capture prey Cnidoglandular lobe: The median band located on the upper portion of the mesenterial filament, this band consisting of a mesogleal core and an epithelium including supporting cells, gland cells, and nematocysts Complete septa: Connexon: an assembly of six proteins called connexins that form the pore for a gap junction between the cytoplasm of two adjacent cells Cubozoa: Any of several jellyfish-like marine cnidarians of the class Cubozoa of tropical and subtropical waters, having an almost transparent cube-shaped body, complex eyes, and stinging tentacles containing potent toxins in some species; e.g. box jellyfish Digestive epithelium: The layer of cells that forms the luminal surface or lining of both the small and large intestine (colon) of the gastrointestinal tract. It is composed of simple columnar epithelium Dimorphic life cycle: When the life cycle of the animal includes two distinct and physically different body types. The life cycle progresses from the immature form to the reproductive type. Or both forms may appear together in colonial types of dimorphic organisms Diploblastic: Organisms formed from only the two primitive cell layers--endoderm and ectoderm. Although there may be some type of a matrix between the two cell layers, often referred to as mesoglea or mesenchyme, it is not a true tissue layer Ectoderm: The outermost cell layer that forms the epithelium and nervous systems of an animal. The ectoderm and endoderm are the two primary germ layers Endoderm: The innermost layer of cells that forms the digestive tract and other associated organs. The ectoderm and the endoderm form the two primary germ layers of an animal Ephyra: Free-swimming, miniature medusa of scyphozoans produced by asexual budding from the scyphistome Epithelomuscular cells: Cells that line the outer surface of cnidarians. These cell have two functions: the first is to form the outer body covering of the animal, the second is in movement by contraction of the myoneme portion of the cell. Extracellular digestion: The final breakdown of ingested food to components small enough to be absorbed across a cell membrane occurs outside of the cell in the lumen of the digestive tract; --intestine or digestive gland, for example Gap junctions: specialized intercellular connection between a multitude of animal cell-types. They directly connect the cytoplasm of two cells, which allows various molecules, ions and electrical impulses to directly pass through a regulated gate between cells Gastric filaments: a fringe of short, threadlike filaments whose secretory cells secrete digestive enzymes. They are located on the floor of each gastric pouch. Gastrodermis: The name given to the endodermal cells that line the gastrovascular cavity (coelenteron) of cnidarians Gastrovascular cavity: The name given to the internal cavity of the cnidarians. A blind-ended (incomplete) gut with only one opening. Food is to be digested and undigested food that must be eliminated pass through the mouth. The cavity is lined by gastrodermis Gastrozooid: Polyps in colonial hydrozoans specialized for feeding; also referred to as hydranths Gastrulation: During embryological development this stage results in the blastula is converted into a gastrula. Cells migrate toward the inside of the embryo from the region where the blastopore will form to create the second germ layer (endoderm). The embryo changes from having only one cell layer to having two cell layers Gonozooid: Polyp in colonial hydrozoans specialized for producing medusa, the reproductive stage in the life cycle. Gonozooids are also referred to as gonangia Hydranth: one of the feeding zooids of a hydroid colony Hydrostatic skeleton: Formed from a fluid-filled and closed cavity surrounded by a body wall containing muscles oriented in different directions. Muscular contractions maintain the rigid form or change the shape of the organisms allowing movement Hydrozoa: a coelenterate of the class Hydrozoa, such as a hydra or Portuguese man-of-war Incomplete digestive system: A digestive system that has only a mouth and no anal opening. Both ingested food and the undigested food must pass through the same opening to the alimentary tract Incomplete septa: Medusa: The free-swimming, mobile stage of the cnidarian life cycle. This stage, when present, is reproductive and mature gonads form on either male or female medusae. A common example is the jellyfish Mesoglea: The jellylike layer found between the ectodermal and endodermal cell layers of diploblastic organisms. It acts as a type of cement holding the two layers together but, unlike mesenchyme, has few, if any, cells Myoneme: Blocks of segmental muscles found in chordates. The term may also be used to refer to similar blocks of muscle in other animals, but is traditionally used for chordates Nematocyst: This organelle is part of the cnidocyte unique to the Cnidarians. It is the stinging, or eversible, portion of the cell, and it can drill into, entangle, and or stick to potential prey Nerve net: A diffuse network of neurons that conducts impulses in all directions from a point of stimulus Nutritive muscular cells: The cells that form the gastrodermis lining the inner cavity of cnidarians. They carry out two functions: The first is to absorb and digest food and the second is in movement or changing shape by contraction of the myoneme portion of the cell Pedalia: The flat, enlarged base of the tentacles in some cnidarians, usually the cubozoans Planula larva: A planula is the solid, free-swimming larval stage of cnidarians consisting of two cell layers-- an outer ciliated ectoderm and an inner endoderm Polyp: The sessile, asexual stage in the cnidarian life cycle. In some species they are independent organisms; in others, they form colonies where some polyps are involved in food gathering (gastrozooids) and other polyps (gonozooids) produce the reproductive stage Rhopalium: These sensory structures are found around the bell margin of the jellyfish medusa. They always contain a statocyst for balance and sometimes an ocelli for light detection Schyphozoa: an exclusively marine class of the phylum Cnidaria, referred to as the true jellyfish Scyphistoma: The jellyfish, class Scyphozoa, get their name from this unique stage in the life cycle. It is a small polyp existing for only for a short time before developing into a strobila, which then produces the medusa Septa: Sheets of tissue that separate two compartments or cavities Siphonoglyphs: Single or paired ciliated grooves in the oral opening of anthozoans that, along with other features, create the biradial symmetry of the group. The cilia propel water into the gastrovascular cavity Spermaries: An organ in which male gametes are developed Statocyst: A balance organ that senses gravity. It consists of at least one solid statolith surrounded by sensory cilia. As the position of the organism changes the statolith rolls, stimulating different cilia Strobila: Stage in the life cycle of scyphozoan cnidarian formed from transverse fission of the scyphostome and producing the small medusoid ephyra Strobilization: The process that converts the scyphistoma into a strobila during the life cycle of scyphozoans, jellyfish. Transverse divisions of the strobila produce the small, disc-shaped ephyra that develop into the adult jellyfish Tissue-grade: Animals that have tissues but no organ systems. Cnidaria and Ctenophora are examples Triploblastic: Organisms formed from the three cell layers: endoderm, ectoderm, and mesoderm Velum: A thin flap of tissue found around the inner surface of the bell of a hydrozoans medusa or surrounding the mouth of a cephalochordate Platyhelminthes Acetabulum: One of two suckers found on the digenic flukes (trematodes). The oral sucker surrounds the mouth, and the acetabulum is located on the ventral surface Acoelomate: Triploblastic animals that do not have an internal body cavity. This includes the flatworms and ribbon worms. Although the term could be applied to other lower phyla, it is most accurately used with the triploblasts rather than diploblasts Adhesive gland: a gland that secretes an adhesive substance Auricle: Chamber of the heart that receives the blood from outside the heart Blastopore: The opening to the primitive gut (archenteron) that will develop into either the mouth or anus. The blastopore forms during gastrulation Cercaria: A stage in the life cycle of trematode flukes. The cercaria develops from redia found in the intermediate host. This tadpolelike organism is released from the intermediate host to locate either the primary host or another intermediate host Cerebral ganglion: one of a pair of ganglia situated in the head or anterior part of the body in many invertebrates in front of or dorsal to the esophagus Chemoreception: A sensory nerve cell or sense organ, as of smell, or taste, that are able to detect and respond to chemical stimuli Circular muscle: The longitudinal muscle fibres run lengthwise along the body, and the circular fibres encircle it Coelom: A true body cavity completely lined by mesoderm, which forms the peritoneum. Animals with true coeloms are referred to as eucolomates Cysticercus: Larval stage in tapeworms without an aquatic stage in the life cycle. The csyticercus is usually found in the muscle of the intermediate mammalian host and is ingested by the definitive host. It consists of an inverted scolex inside the bladderlike cyst Definitive host: The host at which the parasite spends its final developmental stage, and reaches its mature form Deuterostomia: Phyla, including the Chordata and Echinodermata, that share common characteristics of the blastopore--not forming the mouth, radial indeterminate cellular cleavage in the embryo, and the formation of the body cavity by enterocoelic pouching Diverticulum: Any hollow branch or pouch that extends from the side of an organ Dorsoventral muscle: Muscle running the length of the dorsal side Dual-gland adhesive organ: Glandular system found in some invertebrates, notably Platyhelminthes. One gland secretes glue that holds the animal in place; a different gland secretes a second compound to dissolve the glue and break the attachment Ecdysozoa: Taxon of animals that have a chitinous or collagenous cuticle, molt, and no epithelia cilia. The Ecdysozoa is a new taxon identified by molecular techniques, and it breaks the link between the Annelida and Arthropoda (Articulata) used in traditional evolutionary classification of animals Ectoparasite: Parasitic organisms depend on another animal, their host, for survival. Ectoparasites live on the outer surface of the host. This is the opposite of an endoparasite, which lives inside the host Endoparasite: Parasitic organisms that depend on their host for all, or at least one stage, of their life cycle. Endoparasites complete this requirement inside the host Enterocoel: A process by which some animal embryos develop; a mesoderm is formed in a developing embryo in which the coelom forms from pouches pinched off of the digestive tract Eucoelomate: Organisms that possess a true coelom with mesoderm lining the whole body cavity, unlike pseudocoelomates where the mesoderm is adjacent only to ectodermal tissue Eye cup: Simple eye in invertebrates, eye spot, surrounded by pigment cells that give it a cup-shaped appearance Flame cell: Alternate name for the protonephridia based on their appearance as flickering flames. The flicker is from the cilia that beat inside the cap cell of the protonephridium Gravid proglottid: An organism either filled with eggs or pregnant Incomplete gut: A digestive system that has only a mouth and no anal opening. Both ingested food and the undigested food must pass through the same opening to the alimentary tract Intermediate host: In parasites with complex life cycles involving more than one host, the organisms that contain the larval stages of the parasite Larval amplification: A form of asexual reproduction where, during the life cycle, a single larval organism can produce large numbers of the next developmental stage. A good example is the fluke life cycle. A single sporocyst develops into hundreds of redia Lateral nerve cord: Nerve cord running the lateral length of an organism Longitudinal muscle: Either of the lingual muscles: inferior lingual and superficial lingual. Lophotrochozoa: A new taxon supported by molecular evidence and includes all the animals with a lophophore or a trochophore larval stage. Lophotrochozoans and ecdysozoans, animals with a cuticle, no epidermal ciliature, and who molt, are combined as the protostomes in traditional evolutionary classification of animals Mehlis’ gland: Glandular cells surrounding the ootype in trematodes and cestodes. Its role is unclear. It may be involved in formation of the eggshell, lubricating the egg as it moves from to ootype into the uterus, or its secretions may activate the sperm for fertilization Mesoderm: The third cell layer that develops in the gastrula between the ectoderm and endoderm in triploblastic animals. Mesoderm develops into muscle, connective tissues, and bones, as well as blood and other components of the vascular system Metacercaria: Encysted stage of the trematode fluke's life cycle. It is not present in all life cycles but when it is, it follows the cercaria and forms a dormant cyst. This cyst, often in fish, is consumed by the definitive host. The adult stage follows the metacercaria Miracidium: The ciliated stage that hatches from the egg of a trematode fluke and then invades the first intermediate host, usually a snail, where it develops into a sporocyst Nephridiopore: External openings to nephridia (protonephridia and metanephridia) in invertebrate excretory systems Ootype: Parts of the oviduct in flatworms with openings to the vitelline gland, Mehlis' gland, and seminal receptacle Ovary: emale reproductive organs that produce eggs Ovidult: a ny of the pair of ducts or tubes in female reproductive organ through which an ovum passes from the ovary to the uterus Parenchyma: Mesenchyme cells that form a spongy mass surrounding the internal organs and other acoelomate invertebrates Pharynx: The region of the digestive tract between the mouth and esophagus. In most animals it is muscular and forces food into the digestive tract that lies behind it. In vertebrates it is part of both the digestive and respiratory tracts Platyzoa: The infrakingdom of animals that have three tissue layers but lack a coelom. Molecular evidence supports the taxon that includes Platyhelminthes, Gastrotricha, Gnathostomulida, Rotifera, and the recently discovered Cycliophora Preadapted: a structure or property that developed in an ancestral stock and was useful in a descendant in a changed environment Progottid: Serially repeating segmentlike structures found in tapeworms that contain the reproductive organs. Immature proglottids are continually added at the scolex, and the most mature proglottids, containing thousands of eggs, are found the farthest from the scolex Protonephridia: Osmoregulatory-excretory structure found in some invertebrates. Also called a flame-cell, this tubule is closed at its distal end. The beating of internal cilia pull water across the cell membrane and then propels it down the tubule Protostomia: Phyla that share common characteristics of the blastopore forming the mouth, spiral determinate cellular cleavage in the embryo, and the formation of the body cavity by schizocoely Pseudocoelomate: Animals that have a body cavity that is not completely lined by mesoderm. In the past these organisms were referred to as the phylum Aschelminthes but this is no longer considered acceptable because there is no apparent common ancestor to the group Radial cleavage: During development as the cells of the zygote divide, the products of the cell division remain stacked directly on top of each other Radial symmetry: When an organism's body parts are arranged around the oral-aboral axis so that any plane passing through this axis results in two identical halves Redia: A stage in the life cycle of trematode flukes. The redia in the intermediate host develop from germ cell in the sporocyst. Redia also contain numerous germ cells that will develop in cercaria, an example of larval amplification Releaser gland: A gland releasing a secretion consisting of disintegrated cells and their secretory products into the lumen Rhabdite: Found in the epithelium of free-living flatworms, and when released dissolve to produce mucus, which may also help in defense because it contains toxic chemicals Schizocoel: A true body cavity that forms by schizocoelus splitting of the mesoderm Scolex: This unique attachment organ of the tapeworms is the most anterior part of the animal and is used to attach to the host. It consists of adhesive suckers and, in some species, hooks. Proglottids develop from behind the scolex Seminal receptacle: Part of the female reproductive system where sperm received from the male during mating is stored and later used to fertilize the eggs Seminal vesicle: In invertebrates, part of the male reproductive tract where sperm is stored prior to mating; the accessory gland in the male reproductive system of amniote vertebrates that produces the fluid part of the ejaculate Sperm duct: part of the male reproductive system of many vertebrates; these vasa transport sperm from the epididymis to the ejaculatory ducts Spiral cleavage: Pattern of cell division in the developing embryo where the products of the cell divisions shift by rotating either clockwise or counterclockwise so that the resulting daughter cells lie in the furrow of the underlying pair of cell. The opposite of radial cleavage Spiralia: Taxon of animals with spiral embryonic cleavage of the cells during early development Sporocyst: A stage in the life cycle of trematode flukes. The sporocyst develops from the mericidium found in the intermediate host. Each sporocyst contains the germ cells that will develop into numerous rediae, an example of larval amplification Syncytium: Protoplasm that contains numerous nuclei not separated from each other by plasma membrane. This creates a multinucleate cellular appearance for a tissue that appears to lack cell boundaries Tegument: The outer covering of parasitic flatworms, including flukes and tapeworms, consisting of a syncytial outer layer of cytoplasm connected to cell bodies embedded deep in the underlying protective mesenchyme Testis: Male reproductive organs that produce sperm Triploblastic: Organisms formed from the three cell layers: endoderm, ectoderm, and mesoderm Yolk (vitelline) glands: Gland in many invertebrates that provision the egg with yolk, which supplies the developing embryo with nutrients Bryozoa Ancestrula: The founding zooid that undergoes asexual budding to form a bryozoan colony Bryozoa: Are a phylum of aquatic invertebrate animals; long, filter feeders that sieve food particles out of the water using a retractable lophophore, a "crown" of tentacles lined with cilia Cardiac stomach: The large anterior foregut, or cardiac stomach, occupies much of the posterior aspect of the head and the anterior thoracic body cavity Cecum: is an intraperitoneal pouch that is considered to be the beginning of the large intestine Coleom: A true body cavity completely lined by mesoderm, which forms the peritoneum. Animals with true coeloms are referred to as eucolomates Cystide: In bryozoan (ectoproct) colonies the cystid consists of the nonliving shell, or casing, and the living part of the animal that secretes the casing. The cystid doesn't include the lophophore and the part of the body that moves inside the cystid Ectoprocta: Another term for Bryozoan Epistome: Flaplike covering of the oral opening in lophophorates. Formed from the protocoel, it may or may not have a coleomic cavity inside Funiculus: A cord connecting the digestive system and wall of a zooid in some bryozoan colonies. It may be important in exchange of materials between individuals in the colony Lophophorate: Group of animals that have a lophophore-- ring of hollow ciliated tentacles surrounding the mouth Lophophore: A unique double ring of hollow ciliated tentacles that surround the oral opening in a number of animal phyla. There is some debate as to whether these should be separate phyla, and many consider the lophophore to be a unique character of the phylum Lophophorata Lophotrochozoa: A new taxon supported by molecular evidence and includes all the animals with a lophophore or a trochophore larval stage. Lophotrochozoans and ecdysozoans, animals with a cuticle, no epidermal ciliature, and who molt, are combined as the protostomes in traditional evolutionary classification of animals. Mesocoel: The middle of three coelomic spaces found in the tripartate body plan characteristic of the deuterostome lineage of animals. The other coelomic compartments are the protocoel and metacoel Metacoel: The last of three coelomic spaces found in the tripartate body plan characteristic of the deuterostome lineage of animals. The other coelomic compartments are the protocoel and mesocoel Polypide: The soft part of the ectoproct (bryozoan) that includes the visceral mass and the lophophore and can be retracted into the cystid Protocoel: The first of three coelomic spaces found in the tripartate body plan characteristic of the deuterostome lineage of animals. The other coelomic compartments are the mesocoel and metacoel Pyloric stomach: the distal aperture of the stomach, opening into the duodenum; A ring of muscles, the pyloric sphincter, serves as a “gate,” closing the opening from the stomach to the intestine Schizocoelous: One of two ways that a body cavity forms within the mesoderm. (The other is enterocoelic pouching.) The block of mesoderm splits apart to create the coelomic space, a characteristic of the protostomes Statoblast: Asexual bud of freshwater
More Less

Related notes for BIO2135

Log In


Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.