Transcript Major Characteristics

Clip
Shape of Life: Chordata
Different classes, which
include
jawless fishes (e.g.,
lampreys), cartilaginous
fishes (e.g., sharks),
bony fishes,
amphibians, reptiles,
birds, and mammals.
Major Characteristics
Dorsal, hollow nerve cord Pharyngeal pouches
-Spinal cord
-in neck or throat region
-Nerves branch off and
Tail that extends
connect to organs & muscles
beyond the anus
Notochord
- at some point in their
lives
-Supporting rod that lies just
Animation
below the nerve cord
Adult Derivatives of Pharyngeal Pouches
Pouch
Adult derivatives
1
Lining of auditory tube and tympanic cavity (middle ear cavity)
2
Largely obliterated, lining of intratonsillar cleft (tonsilar fossa)
3
Inferior parathyroid glands, thymus
4
Superior parathyroid glands, parafollicular cells of thyroid gland
Dealing with the
environment
*temperature
*salinity
1. Ectotherms
–
Thermoregulation
Regulating body
temperature
Obtain body heat from the environment
2. Endotherms
–
–
–
–
Homeotherm
Generate own body heat- metabolism
High energy requirement
Birds and mammals able to invade colder areas
3. Poikillotherm
–
–
Variable body temperature
Most aquatic animals (excluding sea mammals)- body
temp is same as surrounding H2O
Thermostat:
hypothalamus
Four physical processes account
for heat gain or loss
•
•
•
•
conduction.
convection.
evaporation.
radiation.
Evaporation and convection are the most variable causes of
heat loss.
Thermoregulation involves physiological and behavioral
adjustments that balance heat gain and loss:
1. Adjusting rate of heat exchange between animal and its
surroundings
-Alter amount of blood flowing between body core and skin
-vasoconstriction and vasodilation
-altering diameter of blood vessels
-countercurrent heat exchange in extremities
2. Cooling by evaporative heat loss – panting or sweating
vasodilation
vasoconstriction
Thermoregulation involves physiological and behavioral
adjustments that balance heat gain and loss:
3.Behavioral responses – basking in sun, migration, hibernation
4. Changing the rate of metabolic heat production – only in
mammals and birds; heat produced instead of ATP
(nonshivering thermogenesis); brown fat, blubber, insulation
Endothermy
(Homeothermy)
• Only birds and mammals
• Expensive
– Human – 60% of nutritional intakes goes to providing
heat.
– Metabolic rate of mammals is 10x that of a reptile.
• Homotherms were able to invade colder
environments.
Temperature conservation can became a
problem as animals moved onto land.
Animals can maintain somewhat constant
body temp by…
– Snake warms itself in the sun and cools off by
hiding in the shade (Ectotherms)
– Bees swarm in a hive to raise the temperature
– Dogs pant
– Elephants flap their ears
– Humans shiver
Countercurrent Exchange
• The opposite flow of adjacent fluids that
maximizes transfer rates
– Heat exchange, gas exchange
– Ex:
• Fish use countercurrent exchanges to maximize the extraction of
oxygen from water across the membrane of their gills.
• Bird legs in water, fish tails
Water has about 10,000x less O2 than air.
Countercurrent heat exchangers
Gills
Gas exchange at the gill surface is enhanced by the opposing
flows of water and blood at the gills.
Countercurrent Exchange
-blood flows opposite to
the direction in which
H2O passes over gills,
maintaining a constant
concentration gradient
for O2 between the
blood and the H2O
passing over the gill
surface
Fish: Countercurrent
Also involved in
osmoregulation
Osmoregulation
Management of the body’s water solute concentration
• Marine vertebrates
– ocean is hypertonic
• H2O constantly lost by osmosis
– They produce little urine & drink large amts of seawater.
– Extra salt is actively transported out through the gills.
• Freshwater fish
– Water is hypotonic
• H2O constantly diffuses in by osmosis
– Rarely drink
– Constantly urinate
– Absorb salt through gills
Osmoregulation
• Terrestrial organisms
– Must rid themselves of waste but still retain
water
Nonvertebrate Chordates
• Two groups do NOT have backbones:
1. Tunicates:
-filter feeders, larval form has
chordate characteristics, adults do not
2. Lancelets:
-small, fish-like, live on sandy ocean
bottom
Tunicates
Lancelet
tunicate
lancelet
Most Chordates are Vertebrates
Key Features
•A vertebrate is an animal with a strong,
flexible backbone.
•All vertebrates exhibit bilateral
symmetry and a true body cavity with an
endoskeleton.
•Found in aquatic and terrestrial
environments.
Key Features
Endoskeleton:
•Support
•Attachment for muscles
•Grows with the animal
Fishes
• Aquatic vertebrates that have:
• paired fins – movement
• scales – protection
• gills – respiration (gas exchange)
*there are exceptions to all of these because fish are SO varied
3 classes:
1. Agnatha (Gnathostomulida) -- jawless
2. Chondrichthyes – cartilage skeleton
3. Osteichthyes – bony fish
Major Characteristics:
•Lateral Line System
•Row of sensitive cells that can detect very
small amounts of motion in the water.
•Closed circulatory system
•Well developed nervous system and brain
•Exchange gases using gills- diffusion
•Herbivores, carnivores, parasites, filter feeders,
and Detritivores.
•Movement- contracting muscles on either side of
the backbone
•Excreation-NH3 or NH4+
2 chambered heart
simplest type of true heart
• One atrium and one ventricle
– Atrium- chambers that receive
blood
– Ventricles-chamber that pump
blood out.
• Blood flow to the tissues and
back to the heart is aided by
swimming motions.
• Blood travels from the heart to
the gills, and then directly to
the body before returning
Temperature
• Most aquatic animals (excluding sea mammals) are
poikilotherms.
– having variable body temperature
• Maintain a body temp by seeking a region in the
ocean of optimal temp and remaining there.
• Their metabolic processes do generate heat, but it
is quickly dissipates into the surrounding water.
Skeleton made of
fibers and cartilage
Hagfish
Lack eyes- detect light through sensors on their body
Feed on dead and dying fish
Soft skin devoid of scales
•Lampreys
•Usually parasites
External fertilization. Oviparous ( egg laying)
•Two chambered heart
•Gills used for respiration
•No external ears
•No eye lids
•Have funnel-like mouths lined with sharp teeth.
•In center of mouth is tongue with a tooth like projection.
•Attaches to other fish by suction. It tears a hole in the
fish and injects a chemical that keeps the blood from
clotting. Sucks blood and fluids from its host.
Vertebrate jaws evolved from skeletal supports
of the pharyngeal slits
Most sharks are carnivorous
• Prey may be swallowed whole
or pieces may be torn from
large prey.
– Teeth evolved as modified scales.
– The digestive tract is proportionately shorter
than in other vertebrates.
• A spiral valve, which increases surface area and slows
food movement, is present in the intestine.
•Sharks and Rays
•Complete vertebral
column, movable jaws, and
skeleton with paired fins.
•All of these structures are made up of cartilage
•Whale shark can grow up to 49.5 ft weighing
39,600 pounds.
• Sharks have
streamlined bodies
and are swift
swimmers.
– The tail provides
propulsion.
– The dorsal fins serve
as stabilizers.
– Pectoral and pelvic
fins produce lift.
•Some buoyancy is provided by large amounts of oil stored in
liver, but most must swim continuously to remain in the water
column.
•Continual swimming also produces water flow through mouth
and over gills for gas exchange.
–Some sharks are known to rest on the sea floor and in caves; they
use jaw and pharynx muscles to pump water over their gills while
resting.
•Water enters the mouth and water passes over the gills where the
gases are exchanged.
•Sharp sense of smell.
•Also have lateral
line system.
•Internal
fertilization
Internal fertilization
-Ovoviviparous
• A pair of claspers on the pelvic fins of
males transfers sperm into the female
reproductive tract.
• Some species are oviparous, some are
ovoviviparous, and a few are viviparous.
Viviparous-The embryo develops INSIDE the mother and the mother gives a live birth.
Like people.
Oviparous-animals that lay eggs, with little or no other embryonic development within
the mother. Like chickens.
Ovoviviparous-animals develop within eggs that remain within the mother's body up
until they hatch or are about to hatch. Like fish.
Bony endoskeleton, operculum, & swim bladder
Most abundant and diverse
Skeleton made of
bone
Marine & freshwater
Swim Bladder: thin
sac that acts as a
float. (Filled with
gasses) Can be adjusted
so that the fish can
move to different
levels.
Lateral line system and a keen sense of smell.
Most-external fertilization
No external ears
No eye lids.
1. Gills for gas exchange
•
gas exchange is more difficult for aquatic animals with gills than for terrestrial
animals with lungs because water is denser than air and contains less O2 per unit
volume
2. Two chambered heart
• only vertebrates in which blood flows directly from respiratory organs
to body tissues without first returning to the heart
• Gas exchange occurs by
drawing water over the four or
five pairs of gills located in
chambers covered by an
operculum.
– Water is drawn into the
mouth, through the pharynx
and out between the gills by
movement of the operculum
and contraction of muscles
within the gill chambers.
• Allows bony fishes to breath
while stationary.
mudskippers
Adaptations in Vertebrates for life
on land
Endothermy
Strong Limbs
Lungs
Skin
Muscles
Eggs
~365 mya
Amphibian Basics Clip
Major Characteristics:
•Lives in water as a larvae and on land as an adult
•Moist skin
•Breathes with lungs as an adult
•Lacks scales and claws
•Must return to water to reproduce.
•Age of amphibians: 360-286 mya
Orders of Amphibians
• Order Urodela – salamanders & newts
*long bodies and tails, 4 legs
*moist/wet areas
• Order Anura – frogs and toads
*all can jump
*frogs more closely tied to water than toads
• Order Apoda – caecilians
*least known
*legless
*live in water or burrow in moist soil
*some have fish-like scales in their
skin
Success on Land:
Lungs, stronger bones in
limbs to help support
weight out of water,
breastbone to protect
internal organs.
First vertebrates to adapt
to life on land
Young can only live in water
Undergo metamorphosis and
can live on land
Tadpole stage can
regenerate lost parts
•Smooth skin, no
scales, feet are
webbed, toes
are soft and
lack claws
•no external
ears: have
eardrums or
tympanic
membranes
Eggs usually laid in water
and fertilized externally
Amphibian eggs lack a shell &
dehydrate quickly in dry air.
In some species, males or females
may house eggs on their back, in the
mouth, or even in the stomach
Feeding, respiration, circulation, excretion,
response, movement, reproduction
• Feeding:
tadpoles are filter
feeders or herbivores; frogs are
carnivores
*have stomach, small intestines,
large intestines, cloaca
• Respiration:
•
*tadpoles have gills; adults have
lungs and use their thin, moist
skin (moist surface of mouth).
Excretion: uric acid -kidneys
filter wastes from blood, make
urine which is stored in bladder
until can be released
Circulation:
– 3 chambered heart
• 2 atria, 1 ventricle
• double-loop circulation
– oxygenated and
deoxygenated blood mix in
the one ventricle
Feeding, respiration, circulation, excretion,
response, movement, reproduction
• Response:
*well developed nervous
systems, specialized sections
of brain
*good eyesight
*hear with tympanic membrane
– transmits vibrations
•Movement:
body
*tadpoles swim – tail for propulsion
*adult amphibians walk or jump – legs at sides of
Feeding, respiration, circulation, excretion,
response, movement, reproduction
Reproduction:
*use external fertilization
*Oviparous – lay eggs
*Reproductive
posture is
called
amplexus
Ecology
•Food for
other
animals
•Some can
produce
poison defense
Blue Poison Frog
• Amphibians: In Cold Blood
(Sir David Attenborough ) Video
Turtles, crocodilians, Lizards, and Snakes
~300 mya
In Cold Blood Clip
Major Characteristics:
•Dry, scaly skin
•Scales made of keratin
Helps prevent water loss
With scales or plates
Reptiles:
Major Chara. Clip
Major Characteristics:
•Lungs
Able to breath air
•Terrestrial eggs with
several membranes (Oviparous)
internal fertilization
Development of amniotic egg
• Oviparous: animals that lay eggs
• One of the most important adaptations for
life on land.
• Does not need water
for reproduction
Development of amniotic egg: egg covered w/a shell that
protects the developing embryo from drying out
Excretion: uric acid
• Some species of lizards and snakes are
viviparous, their extraembryonic membranes
forming a placenta that enables the embryo
to obtain nutrients from its mother.
Egg Layers
All turtles
All tortoises
All crocodilians
Some lizards
Iguanas
Water dragons
Geckos
Veiled chameleons
Panther chameleons
Monitors
Snakes
All pythons
Kingsnakes
Milksnakes
Rat snakes
Corn snakes
Livebearers
Some lizards
Solomon Island skink
Blue-tongue skink
Shingle-backed skink
Some chameleons
Jackson's chameleon
Some snakes
All boas
All vipers
Garter snakes
Limbs, if present, having toes
with claws used for climbing,
digging, and moving around on
land.
Ectotherm: animals with a
body temperature that is
influenced by the
environment
*Due to ectothermy, reptiles can survive on less than 10%
of the calories required by mammals of comparable size.
*uses behavioral
adaptations to
absorb solar energy
and regulate its
body temperature.
Snakes
• Jacobson's organ
• Flicking tongue
helps transmit
odors toward
olfactory organs on
roof of mouth.
• Most reptiles have a threechambered heart; although, the
ventricle is partially divided.
– The partially divided ventricle
reduces mixing of
oxygenated and
deoxygenated blood.
Intro to Birds Clip
Strong Chests muscles
•Only group adapted to life in the air.
•Body covered with feathers
•Modified scales
•Made of the protein keratin and develop in pit in the birds’ skin.
•Two types: Contour (Lift) & Down
(Warmth)
•Help birds fly and keep warm
•Attract mate
•In some species-waterproof
Clip
The bones have a
honeycombed internal
structure that provides
strength while reducing weight
Birds
have the following
adaptations to flight
Wings
which are
Homologous to
front limbs
in other
vertebrates
Tutor
Vista Clip:
Birds
Feathers
Strong chest
muscles
that also
that power
Provide
warmth
Upward and
downward wing
strokes
Efficient
respiratory
system
Efficient
circulatory
system
that provide
that ensure
One-way flow
of O2-rich air
O2 distribution
to body tissues
Air
Flow
animati
on
Endotherms:
A constant warm temp.
generated internally by a high
metabolic rate.
•Birds have higher metabolic rate than mammals
•Two legs covered with scales
•Modified for specific useperching, walking, etc.
•Front limbs modified into wings.
Molting: birds sheds their feathers at
least once a year (gradual)
Thin hollow bones
-Toothless beak
•Birds have many
different types of
feet and beaks.
Modified for the
life style of the bird.
Reproduction:
•Internal fertilization
•Amniotic eggharder shells than
reptiles
Digestion:
Crop: Storage
Gizzard: Can contain
small stones, help with
the mechanical
breakdown of food
Feeding, respiration, circulation, excretion,
response, movement, reproduction
• Lungs
– but have specialized air sacs and breathing tubes that
pull air in when inhale and make sure that oxygenated air
is always in the lungs – air only moves in one direction,
so yields high metabolic rate (provides energy, and allows
birds to breath at high altitudes)
The respiratory system of a bird more efficient than
the human respiratory system because the bird’s
respiratory system does not mix exhaled air with
inhaled air- air only moves in one direction
Feeding, respiration, circulation, excretion,
response, movement, reproduction
• Response: well-developed sense organs
(great senses of sight and hearing); advanced
brain to interpret and respond during headlong
flight
• Movement: flight, walk, run, swimming
*bones are light and filled with a
scaffolding support
Feeding, respiration, circulation, excretion,
response, movement, reproduction
• Circulation: four chambered heart, double loop
circulation, that segregates oxygenated blood
from unoxygenated blood.
– The complete separation of oxygenated and
deoxygenated blood increases the efficiency of oxygen
delivery to the cells.
• Excretion: nitrogen waste removed from blood by
kidneys, secreted as uric acid crystals (white,
pasty droppings, little water)
– uric acid =Allows water conservation
Birds also have a very well developed
nervous system.
• Acute vision and well-developed visual
and coordinating areas of the brain
aid in flying.
• They show complex behavior especially
during breeding season when
elaborate courtship rituals are performed.
Feeding, respiration, circulation, excretion,
response, movement, reproduction
• Reproduction: separate sexes, internal
fertilization, amniotic eggs
*some parent birds can produce and
regurgitate a substance from the crop that is rich
in protein and fat to feed offspring – “bird milk”;
this is actually just sloughed-off cells from their
crop mixed with saliva and mucus
The Anatomy of a Pigeon
1
When a bird eats,
food moves down
the esophagus and
is stored in the crop.
Brain
Esophagus
Crop
Lung
Heart
Kidney
Air sac
2 Moistened food passes
to the stomach, a twoLiver
part chamber. The
first chamber
secretes acid and
First chamber of stomach
enzymes. The partially
Gizzard Small
digested food moves
intestine
to the second
chamber, the gizzard. 3
The muscular
walls
of the gizzard
squeeze
4 As digestion
the contents,
continues,
while small
the food moves
stones grind the
through
food.
the intestines.
Pancreas
Large intestine
Cloaca
5 Undigested food
is
excreted
through the
cloaca.
Cassowary
Rheas
There are many species of flightless birds: ostrich, penguins
Emus
Ecology
Pollination
Seed dispersal
Control insect populations
Indicator of environmental health
Rachel Carson‘s book Silent Spring - pesticides in the
food chain
Humans, Manatees, Elephants, Kangaroos, Apes, Tigers, Dogs
Major Characteristics
•Body covered with hair made of keratin-provides insulation
•Young nourished in the uterus
•Young nourished w/milk from mammary glands
•lung-breathing throughout lifetime
Intro to mammals Clip
•Differentiated teeth
•Large brains-capable of learning
Major Characteristics
•Endothermic
•Subcutaneous
fat under skin to
conserve heat
•Sweat glands to
cool body
Feeding:
•Carnivores, herbivores, and omnivores.
•Evolution of a strong more powerful jaw enabled
mammals to eat food other than insects.
Reproduction:
•Internal fertilization
Placental (Eutherian) mammals: Live birth
Monotremes:Egg-laying mammals: platypuses
and echidnas
-After hatching, young suck milk from the fur of
the mother who lacks nipples.
Marsupials:Pouched mammals: Kangaroo,
koalas, opossum
**Young are born in an early stage of development and
completes its development while nursing.
Australian monotremes and marsupials: echidna (top left),
marsupial mouse (lower left), sugar glider (right)
Monotremes:Egg-laying mammals
• Excretion-Urea
– less toxic than NH3 and requires less H2O
– NH3 converted to urea in liver
• Kidneys filter blood, add water to make
urine.
Form and Function of Mammals
• Jaws and teeth allow for diverse diet
• Highly developed brains with good senses –
taste, sight (color vision), smell, hearing
(ears with chambers), touch
• Movement varied: run, walk, climb, burrow,
hop, pounce, swing, fly, leap, and swim
Circulation
• Double-loop circulation, 4 chambered heart
• two atria and two ventricles
• deoxygenated and oxygenated bloods are
not mixed
Pig