Unit 1 Notes Bio.2 PDF - Animal Evolution

Animal evolution a characteristics · The first animals emerged around 100 million years ago - multicellularity was a critical evolutionary step in animal development - fossils date back early...

Animal evolution a characteristics · The first animals emerged around 100 million years ago - multicellularity was a critical evolutionary step in animal development - fossils date back early to 560 mil years ago in the Edicavan Period Defining characteristics of animals : - Eukaryotic - multicellular - heterotrophic - ingestion t internal digestion - no cell walls (use collagen for adhesion) Evolutionary milestones : - First prokaryotes appeared 3 5 billion years ago Archean era. - First Eukaryotes emerged 1 8 billion years ago. protozoia era - First Multicellular organism emerged 1 2 billion years ago Protozois era. - Cambrian explosion marked significant animal diversity increase Body Plan Symmetry : · Animals develop different Symmetry types - lack of symmetry - radial symmetry - Bilateral Symmetry A Embryonic development : Diploblastic - two germ layers · Two primary developmental pathways that involve complex germ ends t ectodeum layer formation of the ecto, endo, and mesoderm triploblastic - three germ layers - Protostome development : Spiral cleavage determined Cell Fate Blastopore endo , esto tmesoderm , , becomes month , and said masses of mesoderm form EX : Molluscs and annelids coelom. Dentrosome development : - Radial cleavage , undetermined Cell Rate , Blastopore becomes anus, and the mesoderm folds of archenteron form coelom Ex : Echinoderms and chordates. Body cavities : Acoelomate nobody carity tissue fills everywhere - Pseudo coelomate "raise" body cavity mesoderma endoderm - are not connected coelomate - true body cavity mesoderm & endoderm connect helping with : transport of nutrient , gas , and waste, structure cushions organs , organs grow independently from body wall Phylum Porifera Sponges - Phylum Mollusca-snails a slugs · suspension Feeding - hemocoel-hemoumph Water Flow is critical to - their survival - open circulatory system - choanocytes Capture food particles suspended in water - complete digestive tract - water enters through spongoceol + pores and exits through the osculum - foot, visceral mass, and Mantle · cellular processes - calcium carbonate shell/protective covering - phagocytosis is the primary method or Food absorption - radula-special spiky tongue for eating - Amebocytes distribute nutrients throughout the sponges body Phylum Annelida-segmented worms spongium protein that makes up the sponges"Skeletoni larger true Coelom - is a - hermaphrodites they can produce sperm and egg cells complete digestive tract - - - has spiky spiances to protect themselves - closed circulatory system (blood Phylum Ctenophora - comb jellies - segmentation - Diploblastic - the germ layers - circular tlongitudinal muscles to move - radial symmetry Phylum nematoda-round worms Structural features · - hemocoel-movement of gas t food - have 8 rows of cilia for movement - no circulatory system - have two tentacles with colloblasts to catch Prey = cuticle-protective covering keeps from - modified gastrovascular cavity dehydration - nerve net , can feel a respond to stimuli from anywhere - complete digestive tract - contractile tissue that helps them more through water - ecdysis-shedding cuticle to grow · Evolutionary significance - only longitudinal muscles - part of early free around 770 Million years ago Free - living or parasites - early stage of multicellular development Phylum Arthropoda-insects , crustaceans, ect Phylum Cnidaria-Coral jellies , sea , anemone - small colona large hemocoel - Diploblastic-2 germ layers - highest amount of species diversity - radial symmetry - Cuticle = exoskeleton Contractive tissue - + nerve net - ecdysis-shedding cuticle to grow - gastrovascular carity - jointed appendages - specialized Stinging cells (hematocytes) to catch Prey - segmentation-head, thorax, abdomen Phylum Platy helmenthes - Flatworms - MyriaPods-Centit Millipedes - tripoblastic-3 germ layers Chelicerates - - Arachnids I haveshoe crabs accelomate no body cavity Pancrustaceans crustaceans + insects - - - - - cephalization - Primitive brain - can regenerate - Free-livinga Parasitic Phylum Echinodermata-seastars + sand dollars Amphibians - Deuterestone earliest tetrapods - larvae are bilateral + Adult are semi-radial tied to water at various points in life - endoskeleton - spines that build up internal Skeleton born in water, develop in water and , - water vascular system for gas + nutrient transfer lay eggs in water - tube feet for movement Skin must stay moist for gas exchange Phylum Chordata ex : Frogs, salamander and caecilians , 4) key characteristics Amniotes notochord-skeletal support eggs have 4 extraembryonic membranes Dorsal hollow nerve cord-develops into central nervous system For protection Pharyngeal slits/lefts - develops into gills or ears water inside Post anal tail-extends beyond digestive tract hard cutter shell invertebrate chordates how animals could fully more out of water - lancelets have basic chordateFeatures - Reptiles - tunicates - sea squirts-chordate features as larvae Diapsids-2 holes behind eye socket vertebrae development where jaw muscles attach - gradual complexity uniform teeth E" heuvrestceontributokuteethandnervous system Shelledegsrevent dehydration ↳ tendotherms increasing specialization through evolutionary stages ecto vertebrae chordates exiturtle, lizard , Birds Hagfish + lampreys Simple - vertebrates with NO Jaw Binds-no bladder , no teeth, hollow bones chondrocytes 4 chamber heart and large t efficient , cartilaginous fish-loss of minivilized Skeleton lungs all For Flying non covered gills Mammals ex : sharks, skates and rays , synapsids one hole behind eye socket - Osteichthyes (temporal Tissures) Boney Fish ancestral jaw bones became part of the non monophyletic group Middle ear operculum-flap over gills hair/fur loss of lungs derived trait- (currently swimbladder) endothermic-high metabolic rate ex : ray fin wish, lobefin Fish teeth different size shape bic die+ mammory glands milk - 4) chambered heart tefficent lungs Mammals-monatremes egg laying Mammals Basal group-echidnas + Platypus no nipples-mammory glands appear on skin have hair Mammals marsupials - placenta providesHood , oxygen , and nourishment Short gestation (time in uterus) long time breast Feeding - development happens in pouch occurs while nursing nipples Provide Milk Mammals-eutherian More complex placentad long gestational period complete embryonic development in uterus nipples Provide Milk molluscasubclassess Foot ~eyes , tentacles, radula (spiky tongue) , shell (but lost in some , Species like Sings) ex: Snails & Slugs Diet : algae + predatory Bivalva-two hinged shells that encase a sort body , abductor muscles to open t close Shell Diet-filter feeders ex : clams toysters. Cephalopoda-complex brain, big head that is merged with foot with armsitentacles and a beak to eat Arthropoda subclasses crustaceans-segmented body , hard exoskeleton , and jointed appendages ex : crabs, lobsters Myropoda-wingless many-legged With a head and trunk wr multiple segments , ex :Centipeads & Milipeads Chelicerata Chitinous exoskeleton, Segmented (Chephalothorax + abdomen) - Predatory ex spiders, horshoe crab , mites : insects-exoskeleton , some have wings,3 body segments, jointed appendages open circulatory system 6 legs ex : bee, ant , Fly