Phylum Chordata – Humans, cats, dogs
1. Characteristics
a. Development of a stiff rod (notochord) where muscles attach
b. Hollow dorsal nerve tube
c. Gill slits behind the mouth (a.k.a. pharyngeal slits)
2. Vertebrates - 95% of chordate belong to subphylum Vertebrata
a. Posses vertebrae – hollow, cartilaginous or bony structures that surround the dorsal nerve cord
b. Endoskeleton made of bone
c. Large brain enclosed by a skull
d. Complex heart/circ. System
e. Special outer covering
f. 1-2 pairs of appendages
g. Large coelom (vital organs)
1. Characteristics
a. Slimy skin
b. Unpaired fins
c. Soft eel-like bodies
d. Notochord
e. Cartliagninous skeleton
f. Ex. Lampreys
g. Ex. Hagfish
Class Chondrichthyes – Cartilaginous Fish
1. Characteristics
a. Biting jaws
b. Paired fins
c. Skeleton of cartilage
d. Ex. Skates, rays
e. Ex. Shark
i.Paired gills (5-7 on each side)
ii. Lateral line system
iii. Placoid scales
f. Reproduction – internal fertilization
Class Osteichthyes – Bony Fish
1. Characteristics
a. Ex. Trout, salmon, cod, perch, sole, eel, tuna etc.
b. Skeleton made of bone
c. Swim Bladder for buoyancy
d. Paired fins
e. Lateral line system
f. Circulation
i.Gills
ii. Single loop blood circulation, blood pumped from heart to gills
Class Amphibia – frogs, toads, salamanders
1. Characteristics
a. First to inhabit land
b. Able to live in 2 worlds (water and land)
c. Born in water, gilled larvae or tadpoles
d. Adult air-breathers
2. Adaptations for terrestrial living
a. Limblike fins for movement
b. Lungs instead of gills
c. Improved heart
d. Eggs laid in water
e. Habitat close to water
3. Reproduction
a. External fertilization
b. Eggs do not have protective covering
Class Reptilia – Turtles, crocodiles, alligators, lizards, snakes
1. First fully terrestrial animals which required adaptations
a. Legs bent more
b. Lungs/heart more efficient
c. Skin covered with scales
d. Ectotherms (heat from outside)
i.Regulates body temp by behaviour
2. Circulation
a. 4 chambered heart
3. Reproduction
a. Internal Fertilization
b. Egg encased in leathery shell
c. No care for the young
d. Amniotic egg
i.Amnion – surrounds, protects
ii. Yolk sac - food
iii. Allantois - wastes
iv. Chorion – Oxygen to enter, but retains water
1. Characteristics
a. Wide range of colours, habitats, songs, behaviour
b. Scales on legs and feet
c. Feathers
i.Provide insulation/protection
ii. Contain same protein as reptilian skin
iii. Homeotherms / Endotherms
2. Adaptations for flight
a. Wings
b. Feathers
c. Hollow bones
d. Large sternum for strong muscles
e. 1 ovary
f. Digestion rapid and efficient
g. 4 chambered heart
h. Respiration
i.One way air flow
ii. Air sacs among internal organs and bones
iii. Permits continuous supply of oxygenated air
3. Reproduction
a. Internal fertilization
b. Amniotic eggs
c. Prenatal care
1. Characteristics
a. Warm blooded, air breathing, 4 legged vertebrate
b. Hair
i.Insulates
ii. Camouflage
iii. Whiskers for sensing
iv. Defense mechanism
c. Mammary glands
i.Produce milk for young
ii. Milk is rich in fat, sugar, proteins, 95% water
d. 3200/4100 species are not large (rodents, bats, moles etc)
e. Well developed sense organs and large brain
f. Walk more efficiently
g. Pentadactyl
i.Variations for different species
h. Diversity of teeth
2. Reproduction
a. Monotremes – egg laying mammals
i.Ex. Duck billed platypus and spiny anteater
ii. Female incubates eggs
iii. Milk secreted through surface of the skin/fur
b. Marsupials – pouched mammals
i.Begin development in females body
ii. Crawl into mother’s pouch after immature birth
c. Placenta
i.Birth to live young
ii. Placenta develops in uterus and helps exchange materials from mother’s blood stream
1. Villi – capillaries inside strands of tissue
2. Gases diffuse from mother to baby through villi
iii. Born relatively mature
iv. Varying degrees of maternal care