Animal Phylogeny sponges Cnidaria Echinodermata & Chordata Platyhelminthes Molluska & Annelida Nematoda & Arthropoda tissues Deuterostomes Protostomes molting Phylum Arthropoda Insects, crustaceans, spiders, etc. Aquatic or Terrestrial; HUGE number of species 20 million +. Bilateral. Triploblastic; coelomate. Two digestive openings. Ventral nerve cord. Grow by molting (shedding exoskeleton). Exoskeleton with chitin. Jointed appendages. Phylum Arthropoda Open circulatory system = blood not always in vessels; in open spaces around organs Body plan = segments with jointed appendages (often specialized)
Generalized Arthropod Insect Spider
Arthropod Groups Trilobites = aquatic; extinct Arachnids = spiders, mites, ticks, scorpions Crustaceans = crabs, shrimps, barnacles, rollie pollies Myriapods = centipedes & millipedes Insects Insects Insects = 1-200 million species -Head, Thorax, & Abdomen Organophosphate Resistance in Mosquitoes [ Evolution Explosion ] Environment Org.phos. susceptible insect Org.phos. resistant insect Organophosphates present Dead; made few esterases, org.phos. damages nerves Alive; makes many esterases = Reproduces slowly Adaptive Trade-Off Organophosphates absent Alive; makes few esterases = Reproduces rapidly Alive; makes many esterases = Reproduces slowly
Bt Toxin Resistance in Insects [ Evolution Explosion ] Environment Bt susceptible insect Bt resistant insect Bt toxin present Dead; normal intestinal receptors, Bt damages intestine Alive; resistant intestinal receptors = Reproduces slowly Adaptive Trade-Off No Bt toxin present Alive; normal intestinal receptors = Reproduces rapidly Alive; resistant intestinal receptors = Reproduces slowly Evolution Explosion Questions What do companies that make Btcrops require farmers to do to counteract the evolution of resistance? Cockroaches have been shown to evolve resistance very easily. How are cockroaches controlled in a way that makes evol. of resistance less likely? Drosophila melanogaster Drosophila; the fruit fly Small true fly; feeds on fruits. Genetics & Development well known Egg Larva (maggot) Pupa Adult
Animal Phylogeny sponges Cnidaria Echinodermata & Chordata Platyhelminthes Molluska & Annelida Nematoda & Arthropoda tissues molting Deuterostomes Echinoderms and Chordates When present - dorsal nerve cord. Internal skeletons. Prominent coelom. Similar development. Animal Phylogeny sponges Cnidaria Echinodermata & Chordata Platyhelminthes Molluska & Annelida Nematoda & Arthropoda tissues Deuterostomes Protostomes Deuterostomes Protostomes molting
Phylum Echinodermata Star fish, brittle stars, sea urchins, sea cucumbers, sea lilies ALL marine. Bilateral as larvae. Radial as adults (usually based on 5). Triploblastic; coelomate Two digestive tract openings. Endoskeleton (CaCO 3 ). Water vascular system with tube feet. Echinoderms Urchin Development BILATERAL juvenile larva RADIAL
Animal Phylogeny sponges Cnidaria Echinodermata & Chordata Platyhelminthes Molluska & Annelida Nematoda & Arthropoda tissues Deuterostomes Protostomes molting Phylum Chordata Vertebrates, sea squirts, and lancelets Aquatic or Terrestrial. Bilateral. Triploblastic, coelomate. Two digestive tract openings. Dorsal nerve cord. Chordate Derived Characters Notochord = stiff mesoderm rod; runs length of body Dorsal nerve tube = Nerve tube near dorsal surface, dorsal to notochord Pharyngeal slits = openings to throat on side of body (gill slits). Post-anal tail = notochord, nerve cord, etc. extend beyond anus.
Chordate Derived Characters brain dorsal nerve tube spinal cord post-anal tail pharyngeal slits notochord anus Lancelets Aquatic, Susp. Feeders Obvious muscle segments = somites Motile Lancelet Development Neurulation in chordates involves the formation of neural tube by infolding of ectoderm above the notochord. Neural tube forms spinal cord & brain.
Lancelet Neurulation Vertebrates Aquatic & Terrestrial, Motile Distinct muscle segments = somites Dorsal brain. Endoskeleton (with CaPO 4 ). Vertebrae - around notochord and dorsal nerve cord ( backbone ) Neural crest tissue mobile ectodermal developmental tissue, forms part of nervous system (& other things) Vertebrate Neurulation & Neural Crest Cells
Vertebrate Development Vertebra Somites in Vertebrate Embryo Mouse Chicken
Segmentation in Adult Humans human segmentation Lampreys Jawless Vertebrates Jawless Vertebrate mouth gill openings
Jawed Vertebrate mouth upper jaw gill openings Human Embryo Jawed Vertebrates
Environment Large size, late maturity Small size, early maturity Size Evolution in Fishes [ Evolution Explosion ] Heavy fishing Most individuals killed before reproducing Most individuals reproduce before being killed Adaptive Trade-Off Low-no fishing Large size when reproducing = more eggs each time Small size when reproducing = fewer eggs each time Evolution Explosion Questions What life history characteristics are selected for when individuals are in an environment where d is high? What life history characteristics are selected for when individuals are in an environment where d is low? Danio rerio Zebrafish; zebra danio Small fish (minnow from India) Genetics & Development well known Transparent embryos
Xenopus laevis African clawed frog; aquatic frog Aquatic adults (from Africa) Genetics & Development well known Gallus gallus Chicken; chick Medium sized bird (from Southeast Asia) Development well known Mus musculus House mouse Small rodent (from Eurasia) Genetics & Development well known
Rattus norvegicus Rat, Norway rat Rodent (from Eurasia) similar to but larger than the house mouse Genetics & Development well known Homo sapiens Human Large primate (from Africa originally) Genetics & Development well known Model Organisms Escherichia coli - bacterium Arabidopsis thaliana - plant Saccharomyces cerevisiae - fungus Neurospora crassa - fungus Caenorhabditis elegans - animal Drosophila melanogaster - animal Danio rerio - animal Xenopus laevis - animal Gallus gallus - animal Mus musculus - animal Rattus norvegicus - animal
Energy Storage & Structure Group of Organisms Bacteria - Plants - Fungi - Animals - Extra Glucose Storage no specific molecule Starch Glycogen Glycogen Structural Molecules Peptidoglycan in Cell Wall (made from glucose & protein) Cellulose in Cell Walls (made from glucose) Chitin in Cell Walls (made from glucose) No Cell Walls; Collagen (a protein) Outside of Cells Animal Anatomy Tissues = groups of cells with a similar structure & common function. Organs = group of cells of various tissue types grouped together into specialized centers of function Organ Systems = groups of organs that together carry out major functions Animal Tissues Epithelial = sheet(s) of cells on a sheet of collagen fibers that cover surfaces Connective = sparse cells in an extracellular matrix (usually with collagen) that bind and supports other tissues Nervous = neurons and supporting cells that send electrical signals Muscle = long contractile cells arranged in bundles
Animal Tissues Epithelial Tissue Basement membrane = mat of extracellular collagen under epithelium Simple epithelium = 1 layer of cells Stratified epithelium = >1 layer of cells Squamous epithelium = thin flattened cells; cover surfaces Cuboidal epithelium = cells about as wide as tall; secretory or absorptive Columnar epithelium = tall cylindrical cells; secretory or absorptive Epithelial Tissue
Connective Tissue Loose connective tissue = cells in a loose mesh of collagen and elastin fibers Adipose tissue = with cells used to store fat (FAT TISSUE) Fibrous connective tissue = cells in dense parallel collagen and elastin fibers (TENDONS and LIGAMENTS) Cartilage = cells (chondrocytes) in a collagen and chondroitin sulfate Bone = cells (osteocytes) in collagen and calcium phosphate (CaPO 4 ) Connective Tissues loose fibrous cartilage bone Blood Blood = cells in a liquid matrix (plasma) Plasma = fluid matrix of blood Most blood cells formed in bone marrow Erythrocytes = (Red Blood Cells) transport O 2 using hemoglobin (lack nuclei in mammals) Leukocytes = (White Blood Cells) fight infection (many kinds of cells) Platelets = promote blood clotting to seal wounds
Blood platelet plasma erythrocyte leukocyte Nervous Tissue Neurons = cells with long processes; transmit electrical signal then release a chemical (neurotransmitter) Glial cells = cells that surround neurons for protection, for nutrition, or contain myelin Neuron functional unit of the nervous system cell body axon myelin under a glial cell dendrite synapse
Neuron functional unit of the nervous system electrical signal Neurotransmitter Muscle Tissue Skeletal muscle = voluntary muscles Cardiac muscle = involuntary muscles that form the wall of the heart Smooth muscle = involuntary muscles that form the walls of the intestine, bladder, arteries, and other organs
Muscle Tissue Homeostasis & Regulation Homeostasis = maintenance of stable internal conditions (within a range). EXAMPLE - Pancreas secretes hormones that regulate blood glucose concentration. Glucagon = signals liver cells to break up glycogen to release sugar. Insulin = signals body cells to absorb sugar AND signals liver cells to absorb sugar and store it as glycogen. Blood Glucose Regulation High blood glucose = pancreas cells secrete insulin. Insulin directs body cells and liver cells to absorb sugar. Liver cells store much glucose by converting it to glycogen reduces blood glucose. Low blood glucose = pancreas cells secrete glucagon. Glucagon directs liver cells to dismantle glycogen to release glucose increases blood glucose.
Glucose Regulation Problems with Glucose Reg. Hyperglycemia = high blood glucose. Damages blood vessels, can lead to blindness or ulceration of extremities leading to amputation. Hypoglycemia = low blood glucose. Not enough energy to cells (including brain cells), can lead to loss of consciousness and then coma. Clinical Hypoglycemia = Pancreas over-reacts to high glucose secreting too much insulin. The liver stores too much glucose causing hypoglycemia. Usually treated with diet regulation. Problems with Glucose Reg. Type I Diabetes = insulin producing pancreas cells die (during childhood). Cannot direct liver to store glucose. Need insulin shots. Type II Diabetes = liver cells develop a reduced sensitivity to insulin with age. Liver does not respond well to insulin when blood glucose is high. Dietary management or insulin shots.