VERTEBRATES

CHORDATA1. Have a notochord( replaced in human by

backbone)2. Pharyngeal Pouches- become gills or lungs3. Post –anal tail-disappears in us4. Dorsal hollow nerve chord- becomes the

spinal chord

Fish

3 Types1. Agnatha- Jawless- Lamprey and hagfish2. Chondrichthyes- cartilage fish- sharks,

rays,and skates3. Osteichthyes- Boney fish- majority

Fish Characteristics

• Have gills- water passes over gills. The oxygen in the water is exchanged for the carbon dioxide in the gills. This is called COUNTER CURRENT EXCHANGE.

• 2 chambered heart• Sexual reproduction –most

external fertilization- called spawning• Some have internal fertilization

like sharks• Paired fins• Scales- thin boney plates• Swim Bladder- fills with oxygen or

nitrogen to control swimming depth

Sensory system called LATERAL LINE SYSTEM- detects changes in environment. Found in Chondrichthyes and Osteichthyes.

AMPHIBIANS• Salamanders, frogs, toads, legless caecillans• Thin moist skin- helps to absorb oxygen from

air• Need water for fertilization to occur- sperm needs

to swim to egg.• External fertilization• Ectotherm- body temperature varies according

to environmental temperature• Frogs and toads secrete chemical so they are bad

tasting so predator won’t eat them• Frogs have vocal chords to communicate

Metamorphosis• Go through intermediate stage

before becoming adult

Egg → Tadpole → FROG

fins legs gills lungs 2 chambered ♥ 3

chambered ♥

Reptiles• Crocodiles, Alligators, Snakes• Scaly skin- prevents water loss• Reproduce on land- Internal

Fertilization

• Produce EGGS- covered in leathery material. Amniotic egg- provides nourishment for embryo

• Legs are directly under body for speed

• Some have 3 chambered hearts, most have 4

• Ectotherms• Nutrition- some are herbivores,

predators or carnivores.• Obtain prey by catching, constriction,

or poisoning

Jacobson’s organ- sense organ.

• Snake sticks out their tongue and collects air molecules. Draws tongue into pit in mouth and senses what is there.

BIRDS

Feathers-• made of protein- provides

insulation and enables flight.

• Molting- new growth• Loss of wing and tail

feathers occur in pairs- balance for flight

Wings• Attached to breast bone

called a sternum• Hollow bones- have air

spaces- enables flight

Circulatory/Respiratrory System

• Birds require a lot of energy for flight

• Have a 4 chambered heart

• High heart beat- chickadee- 500/min

human- 70/minOxygen supplied during

inhalation and exhalation

• Endotherm- maintain constant body temperature

• Internal Fertilization- have an amniotic egg with a hard shell.

• Birds make nests and incubate their eggs until hatched

• Adaptations- beak shape and size according to food source

Mammals• Endotherm- maintain constant body

temperature

7 CHARACTERISTICS

OF MAMMALS1. Hair- made of keratin- provides insulation

2. Produce milk for nourishment of young through mammary glands

3. Diaphragm- muscle that helps enlarge chest cavity for air intake

4. 4 chambered heart- oxygenated and de-oxygenated blood do not mix- most efficient

5. Specialized teeth- adapted to what they eat- •pointed incisors- grasping• canines- puncture• molars- grinding

6. Modified limbs- used for food gathering, opposable thumb

7. Developed Brain- able to teach their young, remember what they learn

• Chimps use tools• Brain- has many grooves to increase

active surface area.

Mammalian Diversity-based on reproductive method

1. Placental (90%)-fetus develops in uterus. Nourished through placenta. Gestation (how long in uterus varies)

2. Marsupial- embryo spends short time in mom then develops in pouch(Kangaroo, Koalas)

3. Monotreme- Egg layer like duck billed platypus and spiny anteater