Note 19

Bio II Exam 3 SP26

diploblastic animals

sponges, cnidarians, ctenophores,

sponges

simplest living animals, body plan is simialr to vase

sponges layers

epidermis, mesohyl, choanocytes

epidermis

exterior protection

mesohyl

mid-layer, digestion, reproduction, skeletal secretion

choanocytes

interaceullular digestion of dissolved organic matter

cnidarians

tentacles surround mouth which leads to gastric cavity, waste is excreted through mouth

cnidarian layers

ectoferm, mesoglea “jelly” of jellyfish, endoderm

epithelium of cnidarians

tight layer of cells lining all body compartments

nerves of cnidarians

simple neural net (no brain)

specialized cells in cnidarians,

epithelium, nerves, light sensitve, pseudo-muscles

simple eyes

light sensitvie cells in cnidarians

psuedo-muscles in cnidarians

no true muscle cells, but they do have cells that allow movement

nematocysts

harpoon-like cells used for feeding that inject prey with toxin

ctenophores

used to be though as closely related to cnidarians; move using coordinated beating of cilia

protostome animals

annelids, mollusks, nematodes, arthropods, insects

annelids

bilaterally symmetric segmented worms; true organs and muscles and organ systems

mollusks

gastropods, cephalopods, bivalves

gastropods

marine, freshwater, and terrestrial snakes, a modified coelom that has become small cavities around organs

cephalopods

squid, octopi, jet propulsion system, arms and tentacles, well-developed neural anatomy

bivalves

similar anatomy to gastropods and cephalopods but with no head; filter feeders; two hard shells connected by a hinge; incurrent and outcurrent siphon

nematodes

polysaccharide-rich cuticle that protects them, molts during growth, most are microscopic roundworms

arthropods

most diverse animal phylum, external chitin, chelicerates, myriapods, crustaceans, insects

Insects evoutionary adaptations

desiccation resistant eggs, wings, metamorphosis

metamorphosis

separates life into eating stage and reproductive stage

insect respiration

spiracles and tracheae

spriacles

pores in the exoskeleton

tracheae

internal system of tubes that directs oxygen and removes carbon dioxide

deuterostome animals

hemichordates, echinoderms, chordates

hemichordates

acorn worms & pterobranchs

unqiue hemichordates adaptations

pharyngeal slits and dorsal nerve cord

pharyngeal slits in hemichordates

function in feeding and respiration

dorsal nerve cord in hemichordates

verntral or lateral in all previously seen organisms

Echinoderms

sea stars, sea urchins, and sea cucumners

Echinoderms unique adaptations

water vascualr system, tube feet, pentardial symmetry, exoskelton of porous calcite

water vasular system in echinoderms

permit bulk flow of oxygen and nutrients

tube feet in echinoderms

projection of water vascular system used for locmotion and feeding

chordates

cephalochordates, tunicates, vertebrates

choradate characetristics

pharyngeal slits, notochord, nerual tube, mytomes, tail

notochord in chordates

stiff rod of collagen along the back

neural tube

early feature of embryonic development; becomes dorsal nerve cord

mytomes

muscle segments

cephalochordates

no lateral appendages, fish-like, lacks well-developed brain or eyes

tunicates

adult filter feeding form only has pharyngeal slits in common with cordate traits; chordate traits in larval form

vertebrates

have vertebrae, cranium, well-developed brain and eyes, distincitve mouth, internal skeleton, coelom, closed circulatory system

fish

most divers group of vertebrates; jawless fish, cartilaginous fish, bony fish

bony fish

ray-finned fish and lobe-finned fish

tetrapods

amphibians, reptiles, birds, and mammals

amphibians

aquatic larval form, adult form with simple lungs

amniotes

reptiles, birds, mammals; evolved amniotic egg to reproduce without water

Birds

evolved from dinosaur ancestors, lacks teeth, scales into feathers, hollow bones, circular breathing

mammals

hair, produce milk, monotemes, marsupials, and placentals

montremes

earliest group, lay eggs

marsupials

premature birth

placentals

create temporary organ (placenta) to nourish the embryo