Transcript Common Characteristics

Vertebrate Characteristics
Taxonomy Review
Taxonomy- classifying organisms based on common characteristics and
assigning each organism a universally accepted name.
Kingdom, Phylum, Class, Order, Family, Genus, Species – In order from most
general to most specific
Phylum = Chordata; Sub-phylum = Vertebrata
Classes = Agnatha (jawless fish); Osteictheyes (bony fish); Chondrictheyes
(cartilage fish); Amphibia (amphibians); Reptilia (reptiles); Aves (birds);
Mammalia (mammals)
Carolus Linnaeus
Classification of Vertebrates
Phylum: Chordata
Common Characteristics:
notochord, pharyngeal gill slits, hollow dorsal nerve cord
Sub-phylum: Vertebrata
Common Characteristics:
backbone that supports and protects spinal cord, endoskeleton, distinct
head with skull and brain
Lancelet
Tunicate
Overview of Vertebrate Classes
Total Animal Species: 1,367,555
Total Vertebrate Species: 62,305
(4.5%)
Overview of Vertebrate Classes
Jawless Fishes –
 aquatic animals with pharyngeal gills
 retain larval notochord into adulthood
 skeleton is made of cartilage
Examples – lamprey, hagfish.
Overview of Vertebrate Classes
Cartilage Fishes –
 aquatic vertebrates
 pharyngeal gills
 skeleton made of cartilage
Examples sharks, rays, skates
Overview of Vertebrate Classes
Boney Fish/Ray-Finned Fish –
 aquatic vertebrates with pharyngeal gills
 skeleton composed of bone and covered by
scales
 fins for movement
Examples: salmon, angel fish, trout, perch
Overview of Vertebrate Classes
Amphibians –
 vertebrates that are aquatic as larvae and
terrestrial as adults
 breathe with lungs as adults
 have four legs
 have moist skin and lack scales
Examples – frog, salamander, axolotl.
Overview of Vertebrate Classes
Reptiles –
 Vertebrates with scaly skin
 have lungs and live entirely on land
 shelled egg with specialized (amniotic) membranes
Example – snake, Komodo dragon, turtle.
Overview of Vertebrate Classes
Birds –
 endothermic vertebrates with feathers,
 two legs used for walking and perching
 two wings that lack claws
Example – pigeon, hawk, eagle; bird of paradise.
Overview of Vertebrate Classes
Mammals –
o endothermic animals with fur or hair
o mammary glands produce milk to nourish young
o most have placenta to nourish fetus
Example – human, whale, pig, bat, anteater
Great Transformations: Important Evolutionary Advances
Jaws- Fish
•
The first fishes to be found in abundance in the fossil record were
jawless. These are limited to eating small particles of food by filterfeeding and vacuum suction.
•
Jaws in fishes made it possible for them to eat plants and other
animals and defend themselves by biting.
•
Disadvantage-digestive system had to develop for new diet
Strong Skeleton- Amphibian Adults
•
The first amphibians had strong limb bones and girdles for
movement unsupported by water.
•
The ribs formed a cage that supports and protects the internal
organs.
•
Adult amphibians have more mobility and habitat availability
•
Disadvantage- new environment, predators
Eggs- Reptiles
•
Reptiles evolved from amphibians when climatic changes caused
destruction of amphibian habitat.
•
Reptilian eggs are surrounded by a shell and several membranes
that create a protected environment for the embryo.
•
These “amniotic eggs” contain nutrient-rich yolk used by the embryo
for food.
•
Disadvantage- predators, change in habitat.
Internal Temperature Control- Birds and Mammals
•
Fish, amphibians and reptiles are ectothermic. The have an internal
body temperature that varies with external (environmental
conditions) due to a slow metabolism.
•
Birds and mammals are endothermic. They maintain a relatively
high and constant internal body temperature that is regulated
internally due to a fast metabolism.
•
This adaptation is very important for animals living in habitats where
temperatures and seasons are variable.
•
Disadvantage- more food must be consumed
Iguana
Polar Bear
Penguin

Feeding and Digestion
Herbivorous Digestive Systems
Carnivorous Digestive Systems
-Can eat constantly
-Long coiled digestive system which
helps break down plant material
-Iguanas
-Teeth are flat for breaking down
cellulose rather than for tearing meat
-Shorter digestive system so meat
won’t rot
-Sticky tongue (frogs and salamanders)
to catch insects
-Snakes swallow animals wholeunhinge jaw
-Birds: beaks & claws; crop & gizzard;
large intestine absent or reduced
BENEFITS:
Increases time for complete digestion
Allows symbiotic bacteria to digest
cellulose
BENEFITS:
Sharp teeth tear meat
Short tract speeds enzymes that convert
meat to energy
Part C: Comparing Structure and Function Among Vertebrates

Feeding and Digestion
Digestive Systems

Respiration
Fish
Gills
• Oxygen rich water is pumped over gill filaments where gas exchange occurs.
• Oxygen poor water is pushed out through openings in the sides of the pharynx.

Respiration
Various Lungs

Respiratory Systems and Lungs
Similarities
Lungs- adult amphibians, reptiles,
birds, mammals.
2 lungs- reptiles, birds, mammals
Gas exchange occurs in lungs
Differences
Gills- fish, amphibian larva
Skin or lining of mouth- amphibians
Reptiles- more spongy lungs which
are more efficient than amphibians.
Strong muscles around rib cage.
Snakes- one lung.
Fish- some have lungs, lungfish
Birds- air sac allow for one way
flow of air where lungs constantly
receive oxygen rich blood
Mammals- diaphragm increases
volume of lungs and pulls air into
lungs
Benefits
Lungs are more efficient than gills or skin gas exchange
More surface area= more efficient

Circulation/Internal Transport
Heart Chambers and Circulatory Systems

Circulation/Internal Transport
SINGLE LOOP
Fish: Closed system
from heart to gills,
from gills to the rest
of the body and back
to heart. Two
chambers in heart.
Deliver
oxygen
and
nutrients
to cells
and
remove
wastes.
DOUBLE LOOP
Adult Amphibians: one loop
carries oxygen poor blood
from heart to lungs, other
loop carries oxygen rich
blood from heart to rest of
body. Has 3 chambers.
Reptiles: 3 chambers but
more efficient due to septum
in ventricle. Crocs and
Alligators have 4 chambered
heart.
Birds and Mammals: 4
chambers. Complete
separation of oxygen rich and
oxygen poor blood= most
efficient.

Circulation/Internal Transport
Heart Chambers and Circulatory Systems
The DOUBLE loop creates one loop from the heart to the
lungs and a second loop is from the heart to the body.
Double loop circulation allows for the development of more
advanced lungs - more spongy and highly branched.

Reproduction
Definitions
•
Oviparous: a vertebrate that lays eggs that develop outside the
mothers body. Most fish- salmon. Most reptiles and birds have
amniotic eggs.
•
Ovoviviparous: a vertebrate whose eggs develop inside the
mother’s body but are not nourished directly by the mother’s body.
Some reptiles-snakes & lizards. Guppies.
•
Viviparous: a vertebrate who bears live young and directly
nourishes the unborn young by the mother’s body.
Fertilization
Internal:
External:
Eggs are fertilized
INSIDE the mother’s
body.
Eggs are fertilized
OUTSIDE the mother’s
body.
Adults release eggs and
sperm into the
surrounding water and
sperm swim to the eggs
to fertilized them.
To increase chances,
huge numbers of eggs
and sperm are released.
Most amphibians (except
salamanders)
Allows
for the
species to
reproduce,
to
continue
on
Sperm is deposited
into the body of the
female.
Female’s
reproductive system
covers the embryos
with protective
membranes and a
shell
Reptiles, birds,
mammals
Fertilization
Drawbacks
Benefits
External Fertlization
Large number of offspring
produced
Internal Fertilization
With attention and maternal
care, high percentage of
offspring survive
No specialized reproductive
structures needed
Low percentage of offspring
survive with no parental care,
eggs lost to predators
Only small number of
offspring produced
Need specialized reproductive
structures