Bio Sci Exam 2

• a dorsal, hollow nerve cord
• notochord - flexible, supportive, longitudinal rod located between the digestive tract and the nerve cord
• pharyngeal slits located in the pharynx
• muscular post-anal tail

• invertebrae cordates
• often adgere to rocks and boats
• adult have no trace of chrordate trademarks, but larva do

• invertebrae cordates
• have all four chordate features
• bury itself in marine sand

all chordates with a head

more extensive skull and backbone (vertebral column)

• composed of a series of bone called vertebrae
• enclose the one of the main parts of the nervous system the nerve cord

• jawed vertebrates with 2 pairs of limbs
• first vertebrates on land

• tetrapods with terrestrially adapted egg
• completed the transition to land

• Chordates
• Craniates
• Vertebrates
• Jawed Vertebrates
• Tetrapods
• Amniotes

• are not considered vertebrates because they only have a notochord
• considered a craniates

• sharks and rays
• have a flexible skeleton made of cartilage
• have a lateral line system

a row of sensory organs running along each side that are sensitive to changes in water pressure and can detect minor vibrations caused by animals swimming nearby

• have a skeleton made of bone
• fins are supported by thin, flexible skeletal rays
• most have flattened scales that cover their skin
• operculum that covers a chamber housing the gills
• have a gas filled sac - swim bladder

have a series of rod-shaped bones in their muscular pectoral and pelvic fins

• include salamanders, frogs, and caecilians
• "living a double life"
• first tetrapods to live on land
• they can live their life on land, but need to lay their eggs in the water

• Damp habitats
• moist skin supplements for gas exchange and many have poison glands for defense

• Reptiles, birds, and mammals
• major derived character is the amniotic egg, where the embryo develops within a protective, fluid-filled sac (amnion)
• enabled these animals to complete life cycles on land

• includes lizards, snakes, turtles, and crocodilians, birds (kinda)
• cold-blooded or ectothermic
• adaptations include scales, water-proofed with keratin

using heat generated by metabolism to maintain a warm, steady body temperature

Evolved from a bipedal reptile with feathers

• insulate, allowing enhanced control of body temperature, activity, and endurance
• extensions of feathers on forelimbs and tails led to flight

• Essential Services: consumers of insects, pollinators of flowers, and dispersion of seeds
• Barometers of ecosystem health - pristine and altered habitats

• 2-legged (bipedal) vertebrates with backbones
• feathers - soft, filamentous, flexible, lightweight (unlike scales) - need regular replacement and are essential for temperature regulation and flight
• high body temps.
• light weight and strong generating lift and thrust for flight

• varies in form and function
• toothless
• horny sheath
• no exact parallel among other vertebrates

• structured entirely for flight
• bones lightweight
• spongy
• strutted
• hollow

• Eggs:
• richly provisioned external eggs
• no species bear live young
• Brains:
• large, well-developed - 6 to 11 times larger than comparable reptiles
• highly developed neural system (communication and navigation)

• Have feet that grip tightly
• tendons automatically flex when the bird squats
• locking toes around the branch

• 30 orders
• 193 families
• 2099 genera
• ~ 9700 species

the evolution of additional varied species adapted to different ecologies and behaviors

• Due to adaptive radiation
• Bill size and shape changes in relation to types of food eaten
• Leg length chang in relation to perching and terrestrial locomotion
• Wing shapes change in relation to patterns of flight

correspond to different life styles

• Season and social behavior
• reproductive rate, life span, and age of maturity
• egg size in relation to body size, agility of new chicks, degree of parental care

• More than 150 millon years ago
• transformation of reptilian ancestor into feathered birds (with limited flying abilities)

• Major extinctions have punctuated Earth's history: Class Aves
• starting in late Cretaceous
• at beginning of Pleistoncene (25% loss of existing birds)

• Birds evolved from reptiles and have a lot in common:
• lower jaw composed of several bones
• lower jaw articulates on quadrate bone
• single occipital condyle
• single middle-ear bone
• expanded lateral braincase
• sclerotic ring supports eye
• similar leg structure
• scales
• females are heterogametic sex
• nucleated red blood cells

• the original link
• first solid evidence
• Late Jurassic (155-135 mya)
• central Europe

• endothermic amniotes with hair which insulates the body and mammary glands, which produce milk
• have a relative large brain size compared to other vertebrates and longer parental care

• Monotremes
• Marsupials
• Eutherians (placental mammals)

mammals underwent adaptive radiation giving rise to terrestrial carnivores and herbivores, bats, aquatic whales and porpoises

• endothermic
• hair
• mammary glands
• differentiation of teeth

• oldest linage (most primitive)
• egg-laying mammals

are nutured by a placenta within the uterus, which allows nutrients from the mother's blood to diffuse into the embryo's blood

• brief gestation
• give birth to tiny, embryonic offspring
• offspring complete development attached to the mother's nipples in a pouch or marsupium
• most in Australia and New Zealand

Virginia Opposum

• live young
• commonly called placental mammals b/c their placentas are more complex than marsupials
• young complete development within the mother

• includes: lemurs, tarsiers, monkeys, and apes
• most are still arboreal

• Shoulder and hip joints allow climbing and branchiation
• Grasping hands and feet are high mobile and flexible
• Sensitve hands and feet aid in manipulation
• Short snout and forward-pointing eyes enhance depth perception

• Anthropoids
• Monkeys
• Hominoids (Apes)

• include - gibbons, orangutans, gorillas, chimpanzees, bonobos, and humans
• nonhuman apes have smaller geographic range
• lack tails and relatively large brain siz and flexible behavior
• Chimps are omnivores