Transcript Vertebrate Characteristics

Vertebrate Characteristics
Classification Review
a.
Taxonomy
- classifying organisms based on similarities and differences
- assigning each organism a universally accepted name.
b.
Kingdom, Phylum, Class, Order, Family, Genus, Species
a.
c.
In order from most general to most specific
Acronym - Kings Play Chess On Fine Gold Squares
Carolus Linnaeus
Classification of Vertebrates
a.
Phylum: Chordata
Common Characteristics:
notochord, pharyngeal gill slits, hollow dorsal nerve cord
Lancelet
Tunicate
b.
Sub-phylum: Vertebrata
Common Characteristics:
backbone that supports and protects spinal cord, endoskeleton, distinct
head with skull and brain
Part A: Overview of Vertebrate Classes
a.
Fish - aquatic vertebrates that are characterized by scales, fins
and pharyngeal gills. There are 3 main groups: jawless,
cartilaginous and bony. Ex. Lamprey, dogfish shark, perch.
b.
Amphibians - vertebrates that are aquatic as larvae and
terrestrial as adults. They breathe with lungs as adults, have a
moist skin with glands and lack scales and claws. Ex. Frog,
salamander, newt.
c.
Reptiles - vertebrates that have lungs, scaly skin and a special
type of egg (amniotic). They live entire life out of water. Ex.
Snake, lizard, turtle.
d.
Birds - endothermic, reptile-like vertebrates with feathers, two
legs used for walking and perching and wings that usually
don’t have claws. Ex. Pigeon, hawk, eagle.
e.
Mammals - endothermic animals with fur or hair, and mammary
glands that produce milk to nourish young. Almost all give birth
to live young. Ex. Human, whale, fetal pig.
Part A: Overview of Vertebrate Classes
Total Animal Species: 1,367,555
Total Vertebrate Species: 62,305 (4.5%)
Part B: Important Evolutionary Advances
a.
b.
Jaws in Fishes
•
Fish are considered to be the most primitive living vertebrate.
•
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.
•
The evolution of jaws in fishes made it possible for them to eat plants
and other animals and defend themselves by biting.
Strength of Skeleton in Amphibians
•
Amphibians probably evolved from
lobe-finned fishes. These organisms
faced many challenges transitioning
from water to land.
•
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.
c. Eggs
•
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.
d. Internal Temperature Control
•
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.
Iguana
Polar Bear
Penguin
Part C: Comparing Structure and Function
Feeding and Digestion
Part C: Comparing Structure and Function
Feeding and Digestion
Herbivorous Digestive Systems
Carnivorous Digestive Systems
- Eat constantly
- Teeth and jaw adapted to breaking
down cellulose
- Long coiled digestive system which
helps break down plant material
- Microbes and specialized organs to
assist with digestion
- Eat less frequently
- Shorter digestive system
- Tongue, teeth and jaw adapted to
catch, chew and swallow meat
BENEFITS:
Obtains energy efficiently from
plants
Generally food is readily available
BENEFITS:
High calorie content in meat
Part C: Comparing Structure and Function
Feeding and Digestion
Part C: Comparing Structure and Function
Feeding and Digestion
Part C: Comparing Structure and Function
Respiration
Part C: Comparing Structure and Function
Respiration
•
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.
Part C: Comparing Structure and Function
Respiration
•
Alveoli: Final branchings of the respiratory tree and act as the primary
gas exchange units of the lung. The gas-blood barrier between the
alveolar space and the pulmonary capillaries is extremely thin,
allowing for rapid gas exchange.
Part C: Comparing Structure and Function
Respiration
Part C: Comparing Structure and Function
Respiration
Similarities
Differences
Lungs present in most vertebrate
classes - adult amphibians, reptiles,
birds, mammals.
Gills present in fish and amphibian
larva
Gas exchange occurs in lungs
Amphibians exchange gas through
skin
Air sac in birds allow for one way
flow of air
Diaphragm in mammals increases
volume of lungs
Benefits
Lungs are more efficient than gills or skin gas exchange
More surface area= more efficient
Part C: Comparing Structure and Function
Circulation
•
Single – Loop Circulation: Blood is carried in one loop: the heart to
the gills, then to the body.
•
Double – Loop Circulation: Blood is carried in two loops: one loop
carries blood between the heart and the lungs, the second loop
carries blood between the heart and the body.
Part C: Comparing Structure and Function
Circulation
•
Heart Chambers: Provide a multiple step pathway for blood to be
sent to the lungs for respiration and dispensed to the body's cells.
Part C: Comparing Structure and Function
Circulation
Part C: Comparing Structure and Function
Circulation
SINGLE LOOP
Closed system from heart to
gills, from gills to the rest of
the body and back to heart.
Fish and Amphibian Larva:
Two chambers in heart.
Deliver
oxygen
and
nutrients
to cells
and
remove
wastes.
DOUBLE LOOP
One loop carries oxygen poor blood
from heart to lungs and oxygen rich
blood from lungs to the heart.
The other loop carries oxygen rich
blood from heart to rest of body and
oxygen poor blood from the body to
the heart.
Amphibian Adults and Reptiles: 3
chambers in heart but less efficient
due to single ventricle.
Birds and Mammals: 4 chambers in
heart. Complete separation of
oxygen rich and oxygen poor blood=
most efficient.
Part C: Comparing Structure and Function
Reproduction
•Oviparous: a vertebrate that lays eggs that develop outside the mothers
body.
•Ovoviviparous: a vertebrate whose eggs develop inside the mother’s body
but are not nourished directly by the mother’s body.
•Viviparous: a vertebrate who bears live young and directly nourishes the
unborn young by the mother’s body.
Part C: Comparing Structure and Function
Reproduction
Part C: Comparing Structure and Function
Reproduction
Part C: Comparing Structure and Function
Reproduction
External Fertilization
Drawbacks
Benefits
Large number of offspring
produced
No specialized
reproductive structures
needed
Low percentage of
offspring survive with no
parental care, eggs lost to
predators
Internal Fertilization
With attention and
maternal care, high
percentage of offspring
survive
Only small number of
offspring produced
Need specialized
reproductive structures