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CHORDATE CHARACTERISTICS
• DORSAL NERVE CORD
• NOTOCHORD AT SOME STAGE
(STIFF FLEXIBLE ROD THAT
SUPPORTS THE NERVE CORD)
• PAIRED GILL SLITS AT SOME
STAGE (CONNECTING
PHARYNX TO OUTSIDE)
• OTHER CHARACTERISICS:
– TAIL EXTENDING BEYOND
ANUS
– BILATERAL SYMMETRY
– THREE GERM LAYERS
– COMPLETE DIGESTIVE TRACT
– CLOSED CIRCULATORY
SYSTEM
The Generalized Structure of
a Chordate
Section 30-1
Notochord
Muscle segments
Tail
Hollow
nerve cord
Anus
Mouth
Pharyngeal pouches
Chordate Cladogram
Section 30-1
Mammals
Birds
Amphibians
Fishes
Nonvertebrate
chordates
Invertebrate ancestor
Reptiles
CHORDATE CLASSIFICATION
(BASED ON COMPARISON OF YOUNG WITH
ADULTS)
• SUBPHYLUM UROCHORDATA
ADULTSNO DORSAL NERVE
CORD, NOTOCHORD, OR GILL
SLITS
• SUBPHYLUM
CEPHALOCHORDATA
ADULTS- HAVE NOTOCHORD,
DORSAL NERVE CORD, & GILL
SLITS
• SYBPHYLUM VERTEBRATA
ADULTS- HAVE DORSAL
NERVE CORD, BUT NO
NOTOCHORD OR GILL SLITS
Vertebrate Characteristics
•
•
•
•
•
Endoskeleton for support,
protection, muscle attachment
Bone or cartilage replaces
notochord
Enlarged brain case (cranium) with
spinal cord that is surrounded by
bones (vertebrae)
Definite body form- head, neck,
trunk, tail
Body covering- (skin, scales,
feathers, hair) may be replaced by
shedding or molting
Vertebrate Characteristics Cont.
• Endoskeleton divided into 2 major
divisions:
1. Axial skeleton: made up of the
skull and spine
2.Appendicular skeleton: limb
attachments to the girdles, limbs
are in pairs (fins, legs, wings,
flippers)
• Pectoral girdle: anterior end,
shoulder region
• Pelvic girdle: posterior end,
hip region
Vertebrate Characteristics Cont.
• Respiration (gas exchange)/ moist skin,
gills, lungs
• Excretion (wastes from blood)/ moist skin,
gills, lungs
• Endocrine glands secrete hormones to
regulate body processes
•
Body temperature- warmer body
temperature, greater metabolic rate
a. Cold-blooded (exothermic) varies
according to temperature of
surrounding environment
b. Warm-blooded (endothermic) remains
constant in spite of surrounding
environment
Vertebrate Characteristics Cont.
•
•
Larger, more specialized muscles (more speed,
dexterity, agility, strength)
Different patterns of egg development (food supply
for developing young)
Oviparous, ovoviviparous, and viviparous
Portuguese shark
Vertebrate Characteristics Cont.
• More efficient heart for pumping blood, increase in
number of chambers, no mixing of oxygenated and
deoxygenated blood
Fish (2), amphibians (3), reptiles (3 ½ or 3), birds &
mammals (4)
Single-Loop
Circulatory System
FISHES
Double-Loop Circulatory System
MOST REPTILES
CROCODILIANS, BIRDS,
AND MAMMALS
Vertebrate Characteristics Cont.
• Larger cerebrum (brain)- behavior is more complex
Inborn: inherited (instincts, reflexes)
Learned: acquired (memory, intelligence, skills,
problem solving)
VERTEBRATE TRENDS
1.
REGULATION OF BODY TEMPERATURE
- FROM EXOTHERMIC (FISH, AMPHIBIANS, REPTILES) TO
ENDOTHERMIC (BIRDS, MAMMALS).
- THREE FACTORS INVOLVED:
A) SOURCE OF HEAT FOR THE BODY; BEHAVIOR (FROM ENVIRONMENT)
& METABOLIC ACTIVITY
B) WAY TO CONSERVE BODY HEAT: FAT, FEATHERS, AND
HIBERNATION
C) ELIMINATES EXCESS HEAT WHEN NECESSARY: SHADE, MUD,
WATER, ESTIVAYTION, SWEATING, PANTING
2.
FEEDING
- KINDS OF TEETH & JAWS
- CROPS, GIZZARDS, STOMACHS. EXTRA PARTS: LIVER, PANCREAS,
GALL BLADDER
- INTESTINE LENGTH RELATED TO KIND OF DIET – LONGER IN
HERBIVORES
- CELLULOSE DIGESTION  FERMENTERS, HERBIVORES
VERTEBRATE TRENDS CONT.
2. FEEDING
- KINDS OF TEETH & JAWS
- CROPS, GIZZARDS, STOMACHS. EXTRA
PARTS: LIVER, PANCREAS, GALL BLADDER
- INTESTINE LENGTH RELATED TO KIND
OF DIET – LONGER IN HERBIVORES
- CELLULOSE DIGESTION 
FERMENTERS, HERBIVORES
Overview of Digestive Systems
of Vertebrates
Section 33-3
Esophagus
Stomach
Intestine
Liver
Gallbladder
Pancreas
Cloaca
Crop
Gizzard
Cecum
Rectum
Shark
Salamander
Lizard
Pigeon
Cow
VERTEBRATE TRENDS CONT.
3. GAS EXCHANGE
- GILLS FISH, YOUNG AMPHIBIANS
- LUNGS ADULT AMPHIBIANS (WITH
MUCOUS-COATED SKIN!), REPTILES,
BIRDS, MAMMALS
BIRDS HAVE THE MOST EFFICIENT
SYSTEM (FRESH AIR FLOWS IN ONE
DIRECTION, NO MIXING OF
NEW/USED AIR)
Overview of Vertebrate Lungs
Section 33-3
Nostrils, mouth, and throat
Trachea
Lung
Air sac
Salamander
Lizard
Primate
Pigeon
VERTEBRATE TRENDS CONT.
4. NERVOUS/RESPONSE
- INCREASED CEPHALIZATION BRAIN INCREASES
IN SIZE
- SIZE & COMPLEXITY OF CEREBRUM (SENSORY
INFORMATION & INSIGHT) & CEREBELLUM (BALANCE
& COORDINATION) INCREASES
- FISH HAVE LATERAL LINE TO DETECT VIBRATIONS
& PRESSURE CHANGES
VERTEBRATE TRENDS CONT.
5. CIRCULATION/TRANSPORT
- SINGLE LOOP (FISH) HEART, GILLS, BODY
- DOUBLE LOOP (ALL OTHER VERTEBRATES)
HEART, LUNGS, HEART, BODY, HEART…
- HEART DEVELOPS CHAMBERS & VALVES THAT
PERMIT ONE-WAY FLOW OF BLOOD WITH NO
MIXING OF OXYGEN RICH & OXYGEN POOR
BLOOD
- NUMBER OF CHAMBERS INCREASE AS
ENDOTHERMY INCREASES:
- FISH (2) AMPHIBIANS (3) REPTILES (3½ -4)
BIRDS & MAMMALS (4)
VERTEBRATE TRENDS CONT.
6. EXCRETION (RESPONSIBLE FOR WATER LOSS!)
- REMOVAL OF NITROGEN WASTES FROM BLOOD
- REGULATIONS OF AMOUNT OF BODY WATER: FISH (GILLS),
ALL OTHERS (KIDNEYS-REABSORB USEFUL SELECTIVE
SUBSTANCES)
- NEPHRONS ARE THE STRUCTURAL UNITS OF THE KIDNEY
(NUMEROUS!)
- NITROGEN CONTAINING WASTES:
AMMONIA – HIGHLY TOXIC, REQUIRES THE MOST WATER
(FISH)
- UREA- AMPHIBIANS, MAMMALS; STORED IN URINARY
BLADDER; REQUIRES LITTLE WATER
- URIC ACID- BIRDS (FLIGHT) & REPTILES (HOT AREAS) ;
REQUIRES NO WATER
*FORM OF NITROGEN WASTE BASED ON ENVIRONMENT
VERTEBRATE TRENDS CONT.
7. REPRODUCTION
- MOST VERTEBRATES REPRODUCE SEXUALLY.
- TREND FROM EXTERNAL TO INTERNAL FERTILIZATION;
EXTERNAL TO INTERNAL DEVELOPMENT; MANY EGGS TO
FEWER EGGS AND NO PARENTAL CARE TO MUCH PARENTAL
CARE.
- 3 PATTERNS OF EGG DEVELOPMENT:
a. OVIPAROUS: EGG OUTSIDE FEMALE, FOOD FROM YOLK
MONOTREMES, BIRDS, MOST FISH, REPTILES, &
AMPHIBIANS
b. OVOVIVIPAROUS : EGG INSIDE FEMALE, FOOD FROM
YOLK MANY SNAKES, SOME FISH, SOME SHARKS
c. VIVIPAROUS: EGG INSIDE FEMALE, FOOD FROM
MOTHER MOST MAMMALS, SOME SHARKS
FISH – (ICHTHYOLOGY)
CLASS AGNATHA (JAWLESS FISH)
LAMPREY
HAGFISH
CLASS CHONDRICHTHYES
(CARTILAGINOUS FISH) SHARKS, SKATES, RAYS
*only chondrichthyes & marine invertebrates are ISOTONIC with
their marine environment
CLASS OSTEICHTHYES
(BONY FISH) PERCH, TUNA, BASS, TROUT…
FISH CHARACTERISTICS
1.
2.
3.
4.
SCALES- 2 KINDS (CATFISH HAVE
NONE)
a) PLACOID (TOOTHLIKE) OR b)
CYCLOID (OVERLAPPING), MUCUS,
CHROMOATOPHORES,
COUNTERSHADING
BONY FISH HAVE SWIM (AIR)
BLADDER- ENABLES FISH TO
REMAIN BUOYANT IN WATER, NO
SWIM BLADDER
SHARKS HAVE FINS SUPPORTED BY
CARTILAGE;
- ONLY BONY FISH THAT DO NOT
HAVE RAY FINS ARE THE
LUNGFISHES & COELANTHS- THEY
HAVE FLESHY LIMB-LIKE FINS (CAN
PROVIDE SPPORT & CAN WALK ON
BOTTOM)
FINS OF RAYS OR SPINES
SPECIAL SENSE ORGAN ON SIDES
OF BODY CALLED LATERAL LINES
ON SIDE OF BODY- SENSITIVE TO
PRESSURE CHANGES & VIBRATIONS
IN H2O; “WHISKERS” ON CATFISH
DO TOO.
FISH CHARACTERISTICS CONT.
5.
BONY FISH HAVE ONLY 1
GILL OPENING COVERED BY
THE OPERCULUM (4 PR. OF
GILLS INSIDE); SHARKS
HAVE SEPARATE
OPENINGS/SLITS FOR EACH
GILL
6. REPRODUCTION –
EXTERNAL FERTILIZATION
& DEVELOPMENT IN MOST
FISH. MALES RELEASE
SPERM (MILT) & FEMALES
RELEASE EGGS (SPAWN) AT
NEARLY SAME TIME!
7. DEVELOPMENT OF EGG –
OVIPAROUS,
OVOVIVIPAROUS, OR
VIVIPAROUS
8. TWO-CHAMBERED HEART &
COLD BLOODED – ALL!!
*FIRST ANIMALS TO EVOLVE
KIDNEYS – FRESHWATER
FISH
Circulation in a Fish – SINGLE
LOOP CIRCULATORY SYSTEM
Section 30-2
Gills
Body
muscle
circulation
Digestive
system
circulation
Heart
Oxygen-rich blood
Oxygen-poor blood
Brain and
head
circulation
Sinus Venosus
Oxygen-poor blood
from the veins collects
in the sinus
venosus.
Ventricle
The ventricle pumps
blood into the bulbus
arteriosus.
Atrium
Blood enters the
atrium and flows
to the ventricle.
Bulbus Arteriosus
The bulbus arteriosus
moves blood into the
ventral aorta and
toward the gills.
COUNTERCURRENT FLOW MECHANISM: MECH. FOR
TRANSFER OF O2 FROM H2O TO GILLS.
CONCENTRATION GRADIENT ENHANCES
DIFFUSION.
The blood in the capillaries flow in the opposite direction to the flow of
water. This is called countercurrent system. This ensures maximum intake
of oxygen (80%) by the blood. This is because the blood in the capillaries
always encounter water that has greater concentration of oxygen. This
creates a concentration gradient for a longer time so that oxygen can
diffuse easily into the blood vessel from water.
The Anatomy of a Fish
Section 30-2
Kidney
Pyloric
cecum
Stomach
Vertebra
Muscle
Esophagus
Swim
bladder
Brain
Spinal Gills
cord
Mouth
Operculum
Urinary
bladder
Heart
Anus
Reproductive
organ
Pancreas
Intestine
Gallbladder
Liver
CLASS AMPHIBIA
“DOUBLE LIFE”  BOTH H2O & LAND
1.
2.
3.
4.
5.
6.
7.
8.
SKIN USUALLY THIN & MOIST
(GAS EXCHANGE!)
EARLIEST TETRAPODS (4 FOOTED)
LAND VERTEBRATES!
FEET USUALLY WEBBED; CLAWLESS
TOES
3-CHAMBERED HEART; COLD
BLOODED
RESP. BY GILLS, MOIST THIN SKIN,
AND LUNGS
HAVE NICTITATING MEMBRANE3RD LAYER COVERING EYE (IN
ADDITION TO EYELID)
OVIPAROUS,
OVOVIVIPAROUS,
OR VIVIPAROUS
TEMP/MOISTURE
PROTECTION –
HIBERNATION IN THE WINTER &
ESTIVATION- WHEN HOT & DRY
• Red eyed tree frog
resting seemingly with
its eyes closed, as it
watches through its
third eyelid, a
transparent membrane
also called the
nictitating membrane.
Isolated on white
Amphibians 3-Chambered Heart
AMPHIBIANS
Section 30-3
Amphibians
means
“Double life”
as
larvæ they live in
adults they live on
Water
Land
and have special adaptations such as
Bones
that allow for
Efficient
movement
Lungs are
Ribs
that allow
that provide
Breathing
are
air
Support and
protection
The Life Cycle of a Frog
Section 30-3
Adult
Frog
Young
Frog
Adults are typically ready to
breed in about one to two years.
Frog eggs are laid in water and
undergo external fertilization.
Fertilized Eggs
The eggs
hatch into
tadpoles a
few days to
several
weeks later.
Tadpoles
Tadpoles gradually grow limbs, lose their tails and gills, and
become meat-eaters as they develop into terrestrial adults.
CLASS REPTILIA (HERPETOLOGY)
“CREEPING ANIMALS” (Shelled eggs allowed for life
on land- leathery and flexible!!!)
REPTILE CHARACTERISTICS
1.
2.
3.
4.
BODY COVERED WITH THICK, DRY SCALES (LIFE ON LAND!)
- 1ST GROUP OF VERTEBRATES HAVING SKIN ADAPTED FOR LIFE
ON LAND!
- SHEDDING (MOLTING OCCURS IN SOME- MODS OF SCALESSCUTES (SNAKES) BOTTOM SCALES THICKER; CARAPACE
(TURTLES) UPPER SHELL FUSED TO VERTEBRAE; AND PLASTRON
(TURTLES) LOWER SHELL
LIMBS, IF PRESENT, HAVE CLAWS OR TOES (LIZARD), PADDLE
LIKE FOR SWIMMING (TURTLES), OR ABSENT (SNAKE).
MOST HAVE A 3½ CHAMBER HEART (ONE VENTRICLE
INCOMPLETE SEPTUM)
RESPIRATION BY LUNGS ONLY; EXOTHERMIC
5.
6.
REPTILE CHARS CONT.
REPRODUCTION– INTERNAL
FERTILIZATION; EGG DEV MAY
BE OVIPAROUS (TURTLES &
SNAKES) OR OVOVIVIPAROUS
(SOME SNAKES & LIZARDS);
MOST HAVE EXTERNAL
DEVELOPMENT; SOME HAVE
PARENTAL CARE (ALLIGATORS,
SOME SNAKES)
SENSORY ORGANS– NO
MOVEABLE EYELID, HAVE
PROTECTIVE COVERING OVER
EYE;
- GOOD SENSE OF SMELL- USE
TONGUE TO SENSE AIR AND
SIGNAL JACOBSON’S ORGAN
(IN ROOF OF SNAKE MOUTH) TO
SENSE CHEM. SIGNALS IN AIR
- HEAT SENSORS IN SKIN
(PITS) CAN DETECT WARM
BLOODED ORGANISMS (PREY!!)
- “THIRD EYE” (PINEAL GLAND)
OF TUATARAS IS LIGHT
SENSITIVE ORGAN
The Amniotic Egg
The amnion is a fluid-filled sac
Section 31-1
that surrounds and cushions
the developing embryo. It
produces a protected, watery
environment.
The allantois stores the
waste produced by the
embryo. It also serves
as a respiratory organ.
Allantois
Embryo
Amnion
The chorion regulates Chorion
the transport of
oxygen from the
surface of the egg
to the embryo and
the transport of
carbon dioxide,
one product of
respiration, in the
opposite direction.
Yolk sac
This baglike structure
contains a yolk that
serves as a nutrient-rich
food supply for the embryo.
7.
Shell
PRODUCE AMNIOTIC EGGS –
KEY ADAPTATION FOR LIFE
ON LAND (EMBRYO
SURROUNDED BY MEMBRANES
AND A SHELL).
- SHELL (PROTECTION &
PREVENTION OF H2O LOSS )
AMNION (SURROUNDS
EMBRYO, FILLED W/ FLUID)
YOLK (FOOD SUPPLY)
ALLANTOIS (COLLECTS
DIGESTIVE WASTES) CHORION
(JUST UNDER SHELL –
PROTECTION)
The Structure of a Turtle’s Heart
Section 31-1
Liver
Kidney
Heart
Cloaca
Bladder
Lung
Digestive
tract
To
body
To
lungs
Right
atrium
From
lungs
Left
atrium
From
body
Ventricle
Incomplete
division
CLASS AVES (ORNITHOLOGY)
FEATHERS! (evolved from reptiles
BIRDS
Section 31-2
Birds
have the following
adaptations to flight
Wings
Feathers
Strong chest
muscles
Efficient
respiratory
system
Efficient
circulatory
system
which are
that also
that power
that provide
that ensure
Homologous to
front limbs in other
vertebrates
Provide
warmth
Upward and
downward wing
strokes
One-way flow
of O2-rich air
O2 distribution
to body tissues
BIRD CHARACTERISTICS
1.
2.
3.
4.
SKIN COVERED WITH FEATHERS.
2 PRS. OF LIMBS – ANTERIOR PAIR=WINGS; POSTERIOR PAIR =
FEET (PERCHING, WALKING, SWIMMING); FEET USUALLY HAVE 4
TOES
SKELETON – BONES ARE HOLLOW(AIR SPACES); HAVE LARGE
STERNUM (BREASTBONE) FOR WING MUSCLES.
WARM BLOODED; 4 CHAMBERED HEART
BIRD CHARACTERISTICS
5.
6.
7.
8.
9.
HIGHLY DEVELOPED SENSE OF “VOICE” (SYRINX) “SONG BOX”,
HEARING, SIGHT, BALANCE, & COORDINATION
HIGH METABOLIC RATE – USE A LOT OF ENERGY, EAT A LOT.
NO URINARY BLADDER (NO LIQUID WASTE – SEMI SOLID)
NO TEETH – HAVE GIZZARD FOR GRINDING FOOD; MODIFICATIONS
OF BEAK STRUCTURE ENABLE BIRDS TO HAVE VARIED DIETS.
FEATHERS – CONTOUR (COVER BODY & WINGS); NEED CARE
(PREENING); HAVE COLORS (PLUMAGE); DOWN FEATHERS (CLOSE TO
SKIN, FLUFFY, INSULATION); OIL GLAND AT BASE OF TAIL USED FOR
PREENING (SMOOTHING & WATERPROOFING).
BIRD CHARS CONT.
10.USE OF ENERGY REQUIRES MUCH OXYGEN. LUNGS HAVE
EXTENSIONS CALLED AIR SACS THAT EXTEND INTO BODY
SPACES & INTO HOLLOW BONES. AIR SACS INCREASE SURFACE
AREA, AND ALLOW. ONE WAY AIR FLOW! MOST EFFICIENT
TERRESTRIAL RESP. SYSTEM!! AVIAN TWO-CYCLE PUMP
Birds 2-Cycle Process
•
•
•
8 or 9 extensions of the lungs (air
sacs) act as bellows that temporarily
store air and then contract to force air
through the system. This moves fresh
air through the lungs when birds are
inhaling, and also when they're
exhaling.
- On inhalation, both sets of air sacs
inflate. Inhaled air flows down the
trachea, bypasses the lungs, and fills
up the posterior air sacs (b). At the
same time, the anterior air sacs fill with
stale air from the lungs (d).
- On exhalation, both sets of air sacs
deflate, forcing fresh air from the
posterior sacs into the lungs (c), and
stale air from the anterior sacs out
through the trachea (e). Air takes two
cycles of inhalation and exhalation to
pass through the system and out of the
bird.
AVIAN AIR FLOW
TRACHEA (INHALATION)
POSTERIOR AIR SACS
(1/2)
EXHALE
LUNG *O
2
LUNG *O ABSORBED
(1/2)
2
ANTERIOR AIR SACS
ABSORBED
EXHALE
TRACHEA (OUT)
BIRD CHARS CONT.
11. AMNIOTIC EGG COVERED WITH LIME SHELL; INTERNAL
FERTILIZATION & EXTERNAL DEVELOPMENT (OVIPAROUS);
SOME YOUNG ARE HELPLESS AT BIRTH, OTHERS CAN CARE FOR
SELVES
CLASS MAMMALIA (evolved from reptilesearlier in history than birds)
MAMMAL CHARACTERISTICS
1. Skin covered with hair or fur with
layer of fat underneath; may
contain glands- sweat, tear, scent,
sebaceous (oil), and mammary
2. All are endothermic- generate
their own body heat by
metabolism; must conserve heat
of environment (harsh), yet must
remove excess heat at other
times
3. Some are oviparous (platypus,
spiny anteater); most are
viviparous- nourished by mother
before birth (placenta) and after
birth (mammary glands)
MAMMAL CHARS CONT.
4. Lung breathers- have a diaphragm- a muscular
sheet separating the thorax and abdomen that
is used for breathing along with rib muscles
MAMMAL CHARS CONT.
5. Four chambered heart- 2 loops- one goes to
and from the lungs while the other goes to
and from the body- more efficient- no mixing
of O2 rich and O2 poor blood- RBCs w/o
nuclei
MAMMAL CHARS CONT.
6. Moveable tongues& eyelids, and external fleshy ears
7. Teeth vary- canines, incisors, and molars, for heterotrophic
nutrition/ carnivores, herbivores, omnivores (scavengers,
predators, vampires, ruminants, and filter feeders)
8. 2 pair of limbs- adapted for running, swimming, flying, grasping,
climbing, walking, digging, burrowing- each foot has 5 toes w/
claws, nails, hooves, or fleshy pads
Canines are pointed teeth. Carnivores
use them for piercing, gripping, and tearing.
In herbivores, they are reduced or absent.
Chisel-like incisors are used for
cutting, gnawing, and grooming.
Molars crush and grind food. The ridged shape of the wolf’s molars and premolars
allows them to interlock during chewing, like the blades of scissors. The broad,
flattened molars and premolars of horses are adapted for grinding tough plants.
MAMMAL CHARS CONT.
9. Well developed kidneys that regulate
the composition of body fluids- remove
urea, remove or retain water, salts, and
sugars- have urinary bladders w/ fluid
excretion (urine)
10. Highly developed brain- cerebrum
(learning and memory), cerebellum
(coordination & balance) and medulla
(internal regulation)
11. Usually 7 vertebrae in neck, 3 bones in
ear
12. Testes usually external, fertilization
internal- females have repro cycles
(estrus/ menstrual) and gestation
periods (pregnancy), internal
development- parents usually care for
young until adulthood
13.3 subclasses (based on method repro)monotremes, marsupials, placentals
MONOTREMES
• EXTERNAL AMNIOTE
EGGS WITH SHELLS
• NO VAGINA OR
UTERUS
• NO NIPPLES –
GLANDS OPEN ONTO
SKIN
• ADULTS HAVE BILLS
(NOT LIPS)
• EX. PLATYPUS
SPINY ANTEATER
(ECHIDNA)
MARSUPIALS
• VENTRAL
ABDOMINAL POUCH
• YOUNG BORN
UNDEVELOPED –
MUST COMPLETE
DEVELOPMENT IN
POUCH
• NIPPLES INSIDE
POUCH
• DOUBLE UTERUS &
TWO VAGINA –
SEPARATE
OPENINGS
PLACENTALS
• SEPARATE URINARY &
VAGINAL OPENINGS
• FLUIDS FROM TESTES &
BLADDER REACH OUTSIDE
THROUGH COMMON
OPENING AT TIP OF PENIS
• DOUBLE OR SINGLE
UTERUS, BUT ALWAYS
SINGLE VAGINA
• FETUS ATTACHED TO &
NOURISHED BY PLACENTA
DURING DEVELOPMENT
• PLACENTA IS THE
CONNECTION BETWEEN
MOTHER & EMBRYO. IT
IS FORMED FROM
EMBRYONIC & UTERINE
TISSUE.
Section 33-1
Cladogram of Chordates
Nonvertebrate chordates
Jawless fishes
Cartilaginous fishes
Bony fishes
Amphibians
Reptiles
Birds
Mammals
Diversity of Chordates
Temperature Control in Chordates
Body Temperature (°C)
Section 33-2
Environmental Temperature (°C)
Overview of The Circulatory Systems
Section 33-3
of Vertebrates
Single-Loop
Circulatory System
FISHES
Double-Loop Circulatory System
MOST REPTILES
CROCODILIANS, BIRDS,
AND MAMMALS
Section 33-3
Comparing Functions of Chordates
Function
Nonvertebrate
Chordates
Fishes
Amphibians
(adult)
Reptiles
Birds
Respiration
Gills and
diffusion
Gills/air sacs
Simple lungs
and skin
Lungs
Lungs (tubes Lungs
and air sacs; (alveoli)
one-way flow)
Circulation
No true
chambers
Single loop; 2 Double loop;
chambers
3 chambers
Double loop;
3 chambers
Double loop;
4 chambers
Double loop;
4 chambers
Excretion
Gills and
gill slits
Kidney and
gills
Kidney
Kidney
Kidney
Response
Simple; mass Cephalization; Cephalization; Cephalization; Cephalization; Cephalization;
of nerve cells small
small
small
large
large
cerebrum
cerebrum
cerebrum
cerebrum
cerebrum
Kidney and
gills
Mammals
Section 33-3
Comparing Functions of Chordates
Fishes
Amphibians
Amphibians
(adult)
(adult)
Reptiles
Birds
Mammals
Muscles on
either side of
backbone
Limbs stick
out sideways;
muscles and
ligaments
Limbs point
directly
toward
ground;
muscles and
ligaments
Upper limbs
are wings; 2
feet; muscles
and ligaments
2 or 4 legs;
walk with legs
straight under
them;
muscles and
ligaments
Reproduction External
fertilization
External
fertilization
External
fertilization
Internal
fertilization;
shelled egg
Internal
fertilization;
shelled egg
Internal
fertilization
and
development
Temperature Ectothermic
Control
Ectothermic
Ectothermic
Ectothermic
Endothermic
Endothermic
Function
Movement
Nonvertebrate
Chordates
Muscles,
no bones
Section 32-2
Orders of Placental Mammals
Order
Characteristics
Examples
Insectivores
Long, narrow snouts, sharp
claws
Shrews, hedgehogs, moles
Sirenians
Water-dwelling, slow-moving
Manatees, dugongs
Cetaceans
Live and breed in ocean, come
to surface to breathe
Whales, dolphins
Chiropterans
Winged, capable of true flight
Bats
Rodents
Single pair of long, curved incisor
teeth in upper and lower jaws
Mice, rats, voles, squirrels,
beavers, porcupines, chinchillas
Section 32-2
Orders of Placental Mammals
Order
Characteristics
Examples
Perissodactyls Hoofed, with an odd number of
toes on each foot
Horses, tapirs, rhinoceroses,
zebras
Carnivores
Sharp teeth and claws
Tigers, hyenas, dogs, foxes, bears,
raccoons, walruses
Artiodactyls
Hoofed, with an even number of
toes on each foot
Cattle, sheep, goats, pigs, ibex,
giraffes, hippopotami, camels
Proboscideans Trunks
Asian and African elephants,
mastodons and mammoths
Section 32-2
Orders of Placental Mammals
Order
Characteristics
Examples
Lagomorphs
Two pairs of incisors in upper
jaw, hind legs allow leaping
Snowshoe hares, rabbits
Xenarthrans
No teeth (or very small teeth in
the back of the jaw)
Sloths, anteaters, armadillos
Primates
Highly developed cerebrum and
complex behaviors
Lemurs, tarsiers, apes, gibbons,
macaques, humans