Biology 1407 Exam 4-Delgado Latest(2024/2025) Updated Questions and Answers with complete solutions.

Hox genes - control the expression of genes that influence animal morphology (sponges are simple animals that do not have Hox genes) acoelmates - triploblastic animals without a coelom, their bodies are solid and have no cavity. Ancestors of animals... - diverged from ancient fungi, between 675 million and 800 million years ago, believed to be a suspension feeder similar to Choanoflagellates Animals are.. - -multicellular (without cell walls) -heterotropic -develop from embryonic layers -ingestive archenteron - pouch that forms during gastrulation (from and indentation called the blastospore) to become the gut. Bilateral Symmetry - -have top (dorsal) and bottom (ventral sides), left and right sides, and anterior/posterior sides -generally animals that move actively from place to place Body cavities- coelom - -typical in triploblastic animals -coelom is fluid or air filled space between digestive tract and outer wall Body Plan - -a set of morphological traits integrated into a functional whole -can be used to characterize different types of animal -includes: symmetry, tissue, body cavities, and early embryo developmentCambrian period - -led to first arthropods, chordates, and echinoderms -animals adapted to have hard, mineralized skeletons Cenozoic Era - -65.5 million years ago to present -mass extinctions (goodbye dinosaurs) -mammals grew in size and diversity to accommodate new ecological niches Tunicates - -have notochord, hollow nerve chord, gill slits, and post anal tail as larvae -invertebrate -Phylum urochordata cephalization - -linked with bilateral symmetry -concentration of nervous/sensory equipment on anterior end Choanoflagellates - suspension feeder similar to animalia's common ancestor Chondrichthyes (sharks, rays) - Clade Bivalvia (clams) - -feed by suspension, traps fine particles in mucus coating the gills Clade Cephalopods (Squids) - -not all have shells anymore -bite at prey with beak like jaw that secretes poisonous saliva Clade Errantia - -marine and mobile -most have parapodia: paddle like appendages for locomotion -parapodium have Chaetae: bristly chitinous projections Clade Gastropoda (snails and slugs) - -mantle cavity functions as a lung -feed with radula used for grazing or boring hiles in bivalve shellsclade polyplacophora (chitons) - -shell made by the mantle -feeds using radula to scrape and ingest algae Clade Sedentaria - -fewer chaetae -less mobile -Earthworms and leaches Coelomates - animals that have a true coelom derived from mesoderm tissue (triploblasts) Deuterostomes - -radial cleavage (parallel/perpendicular cell division) -indeterminate cleavage -mesoderm buds off archenteron wall to become coelom -anus develops from blastopore Diploblastic - Animals with only two germ layers (cnidarians and comb jellies) Dorsal hollow nerve cord - develops from ectoderm and eventually into the central nervous system 4 distinct periods of evolution - -neoproterozoic era -paleozoic era -mesozoic era -cenozoic era Ectoderm - the germ layer covering the surface of the embryo (gives rise to skin and central nervous system) Embryo Development - -includes cleavage patterns, coelom formation, and the fate of the blastopore-protostomes and Deuterostomes Endoderm - inner germ layer (lines digestive cavity and other organs such as liver and lungs) Four Common Chordate Features.. - -notochord -dorsal hollow nerve cord -pharyngeal slits -muscular, post anal tail Gastrulation - formation of distinct layers of embryonic tissue that eventually develop into distinct body parts Hagfishes - -clade myxini homeobox - is a DNA sequence within genes that involve the regulation of patterns of anatomical development. invertebrates - -animals without a backbone -95% of known animal species Lampreys - -clade Petromyzontida Lancelets - -Have notochord, hollow nerve chord, gill slits, and post anal tail as adults. -invertebrate -clade cephalochordata lophophore - Crown of ciliated tentacles for feeding -component of Phyla Ectoprocta and BrachiopodaMesozoic Era - -251-65.5 million years ago -coral reefs formed, birds evolved, and some reptiles returned to water as predators -the first mammals (tiny) arose metamorphosis - transforming of sexually immature larva into an adult Muscular Post Anal Tail - contains skeletal elements and muscles so that it can be used as a propulsive force in many aquatic species Neoproterzoic Era - -1 billion to 542 million years ago -known as Ediacara biota, aren't closely related to today's sponges, alga, or animals. Not quite Chordates.. - Urochodates and Cephalochordates are most closely related to chordates but are invertebrate. These include lancelets and tunicates. Notochord - a longitudinal, flexible rod between digestive tube and nerve chord, provides skeletal support for the chordate Only Animals have.. - -nerve cells -muscle cells Paleozoic Era - -542-251 million years ago -Contained Cambrian Explosion -Cambrian period, Ordovician period, Silurian period, and Devonian period -Fish became top predators, arthropods became terrestrial, amphibians and amniotes developed on land.Pharyngeal slits - pouches alongside the pharynx that allow water that enters through the mouth to exit without going through the gut. For some invertebrate chordates they function as suspension feeding devices, while for limbless vertebrates they form gills, and limbed vertebrates use them in ears. Phylum Annelida - -Coelomates -clades are Errantia and Sedentaria Phylum Arthopoda - -largest phyla with 1 million+ species -coelomates -Body segmentation (head, thorax, abdomen), hard exoskeleton (chitin), and jointed appendages have led to diversity and success. -lineages are Chelicerates (scorpions, spiders etc) , Myriopods (centi/milipedes), and Pancrustaceans (insects,crab etc) -pancrustaceans have two clades: hexapoda for insects and crustaceans