Phylum Hemichordata & Chordata

Porifera Platyhelminthes Mollusca Arthropoda Echinodermata Hemichordata Cnidaria Nemertea Annelida Lophophores Chordata Protozoans 2 2

Chordate Relatives Common ancestry revealed by _______________________ and pharyngeal gill slits ________________ form (throat pocketings) at some time during development; used for feeding or gas exchange

Phylum Hemichordata Three body regions ________________ Gill slits ______ circulatory system Dorsal and ventral nerve cord

Phylum Hemichordata ____ species of acorn or tongue worms Ciliated mucus-covered ____________, resembles acorn or tongue ____________ in sediment and feed on sediment or filter feed Elongated ________ with _______________ openings

Fig. 22.29a

Fig. 22.29b

2012 New Hemichordate Worm found found about 1.5 miles (2.5 kilometers) beneath the surface of the Atlantic Ocean has large lips on either side of its head region that reminded researchers of the floppy-eared Stars Wars character full scientific name is Yoda purpurata, or "purple Yoda."

Discovered a new type of acorn worm, scientists have Discovered a new type of acorn worm, scientists have. Named it after Yoda, they did.

Researchers found the worm during the ECOMAR research program, which uses a remotely operated submersible to search for new animals along the seafloor at the Mid-Atlantic Ridge between Iceland and the Azores. Scientists are interested in these deep sea species, because they are close to the evolutionary link between vertebrates and invertebrates. In other words, the force is strong with them.

Phylum Chordata Three subphyla unified by having a notochord at some point in life cycle and metameric tail ______________ = densely packed muscle fibrils enclosed by sheath in _____ shape; provides skeletal ____________ ____________________ = repetition of similar ____________; ____________ beyond anus

Phylum Chordata Characteristics _______________ _______________ or pharyngeal pouches _______________ hollow nerve cord _______________ tail _______________ muscles

Fig. 23.2b

Chordates Fig. 23.2a

Phylum Chordata Fig. 23.1

Fig. 23.p469a

Fig. 23.p469b

Fig. 23.p472a

Fig. 23.p472c

Evolutionary Adaptations of Chordates From ________ feeding ancestors to active ____________ Mobility Oxygen capture Digestion Circulation Nervous system

Skeletal Changes Skeleton becomes ____________ to work with bigger muscles Allows more _________ movement Fig. 23.p477

Oxygen Capture ______ slit and muscular ___________ will move more water over gills More ___________ is extracted from water Fig. 23.p478a

Circulation Stronger ________ to circulate blood ___________ Fig. 23.p478a

Digestion Digest more food _____________ gut _____________ _____________ Liver Pancreas Fig. 23.p478a

Nervous System More complex for better ________ control of body to capture food _____________ detection of the animals environment Integration centers (________) Fig. 23.p478b

Brain With Three Parts Hindbrain Midbrain Forebrain Fig. 23.14

Chordate Subphyla Phylum. Chordata Subphylum. Urochordata Subphylum. Cephalochordata Subphylum. Vertebrata

Subphylum Urochordata _______ species of tunicates or sea squirts _____________ derivative of chordate line Adults bear _____ resemblance to other chordates, but ________ features indicate nerve cord and notochord These disappear during metamorphosis Only chordate feature remaining = ____________ (filter feed)

Subphylum Urochordata ________________ marine filter feeders Wide _________ of sizes, shapes, and colonial structure All have outer covering (_________) containing tunicin (cellulose-like) and in/ex-current _________

Fig. 23.5

Fig. 23.7

Sea Squirts

Subphylum Cephalochordata Small group of ____ species of lancelets or amphioxus ____________ and free swimming, also burrow in sand with only head protruding Unique feeding apparatus for ____________ feeding (buccal cirri/gill slits) Resemble ____________ more; may represent living descendants of vertebrates

Subphylum Cephalochordata Amphioxus ___________ length of body __________ hollow nerve cord ______ slits _______________ muscles

Amphioxus

Subphylum Vertebrata Around ___________ species of vertebrates Significant not in size or age of group, but its morphological ___________, structural ________________, and ___________ dominance Three novelties bind all vertebrates

Subphylum Vertebrata ________________________ = specialized kind of _______________ that gives rise to nervous system, retina, gill cartilage, and pigment cells Enlargement of _______________ end of neural tube to form the ________ __________________ = backbone composed of _____________ (bony/cartilaginous segments replace notochord during development), cranium (bony/cartilaginous housing for brain), __________ pectoral and pelvic __________________

Subphylum Vertebrata Characteristics All are _______________ symmetrical with regional differentiation ________ region = houses sensory organs, brain, anterior opening to digestive tract Trunk region = body _________ that house viscera ________ or caudal region = lacks viscera, but has _________ and _____________ (function in locomotion, reduced, or specialized)

Subphylum Vertebrata _________________ (serial repetition of body parts) limited to ________ muscles, ____________ (vertebrae and ribs), and the __________ associated with trunk All have _______ at some point in life cycle (breathing organs or transient developmental structures) ____________ circulatory system = arteries move blood to periphery from multi-chambered heart, veins move blood from periphery to heart, capillaries ______________ associated with endoskeleton

Vertebrate Classes

Vertebrate Diversity Major evolutionary innovations among vertebrate groups fall into four categories: 1. Musculoskeletal system 2. Nervous system 3. Respiratory/circulation systems 4. Nature of the egg

Musculoskeletal system Most primitive in ___________ vertebrates (hagfish, lampreys), have reduced braincase and cartilaginous gill-arch supports Hagfish = _____________________ Lamprey = notochord ____________________ by addition of small arches of ________________ in anterior trunk segments and small blocks of cartilage posteriorly--These are evolutionary precursors to vertebrae!

Musculoskeletal system All other vertebrates: replacement of notochord with _______* vertebrae--articulate, protective housing for nerve cord development of ___________________ appendages (from fins to limbs)

Musculoskeletal system appearance of ________ associated with braincase *______________ in sharks/rays-descended from bony ancestors

Nervous System Increased structural complexity allowed an elaborate __________________ to evolve __________________: elaboration of the anterior end of spinal cord to form hollow brain and __________________ (protected by skull) ________________ nervous system: __________ nerves in every body segment (relay brain’s messages to periphery)

Nervous System ______________ nervous system: function _________________ without voluntary control by brain ________________: ________________ activity, slow digestion ____________________: ____________ activity, stimulate digestion This complementary system best developed in ____________ so they can maintain metabolic activity while still able to respond to external conditions

Respiration Respiration: Vertebrates require __________________ than inverts, birds/mammals = highest demands (endothermic) ___________, moist environment (eel, amphibian) = gas exchange ___________ in addition to respiratory organ Gills or lungs = derived from the ___________ Water pumped across ______, get gas exchange Air breathed into ______, gas exchange across epithelial lining

Respiration Birds also have __________ extending from lungs into many parts of body Mammals have _____________ to forcefully pull air in/expel air out

Circulation Allied with respiratory system: ______________ oxygen, nutrients, and water to cells and ______________ wastes/carbon dioxide All systems ______________: heart, arteries, veins, capillaries

Circulation In gilled, ___-chamber heart: one _________, one ____________, blood enters heart via ________, leaves via _________________ in gills (gas exchange), blood proceeds to rest of body

Circulation In amphibians, aortic arches are reduced and modified into __________ in order to pass blood from lungs to ___-chambered heart (atrium separated by ___________, one _____________)

Circulation In snakes and lizards, ventricle also has ___________ (incomplete ___-chambers)

Circulation In birds and mammals, _____________ ______________ of oxygenated/deoxygenated blood, ___-chambered heart, _____________ system with no mixing gives greater blood volume and higher blood pressure (needed for metabolic requirements)

Excretion _____________ = separate food/water from excess salt/waste in blood

The Egg Eggs enclosed by ________ membrane internally and ____________ membrane externally Fish and amphibian eggs pass down oviduct where ____________ chorion or gelatinous protein-polysaccharide material added (____________ egg = no amniotic membrane) ____________ fertilization; _______ climate to prevent desiccation

The Egg Evolution of ____________ egg: equipped with extra membrane ____________ of protection (amnion, yolk sac, chorion, allantois) as well as a ___________________________ shell In reptiles and mammals (monotremes); fertilization ___________; subject to predation Marsupials and placental mammals ___________ young internally (helps young develop to an advanced stage before born)

The End