Download Characteristics of Mammals

OVERVIEW
OF
Vertebrates
All vertebrates have:
•dorsal, hollow nerve cord
•notochord that becomes vertebrae
•endoskeleton
•pharyngeal pouches
(become our eustachian tubes)
•postanal tail at sometime during development
•muscle blocks- modified layers of tissue that
aid in tail movement
•all are in the Chordata phylum
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FISH
AMPHIBIANS
MAMMALS
BIRDS
REPTILES
Characteristics of Fish
Fish use gills to obtain oxygen
Fish have a single-loop
blood circulation.
The heart has 2
chambers.
•Fish must also
ingest amino acids
because they
cannot make them.
•All fish have sexual
reproduction.
Boney fish have 3 unique structural
adaptations:
1. swim bladder that fills with
carbon dioxide to allow them
to float
2. lateral line that is sensory
tissue that allows them to
stay oriented
3. operculum that covers the
gills and works to pump
water into the gills
Key Characteristics of Amphibians
•paired
lungs
•cutaneous
breathing
(skin breathing)
•3 chambered heart
allows for more efficient
oxygen and
carbon dioxide
exchange
•pulmonary vein that
connects lungs and
heart
•Amphibians are also the first
animals to have legs.
•Amphibians go through
metamorphosis
REPTILE CHARACTERISTICS
Partially divided
lower ½ of heart
( 3 ½ chambers)
allowing for less
mixing of
oxygenated blood
and carbon dioxide
blood.
Reptiles have much
larger lungs with
alveoli. These
microscopic air sacs
give increased
surface area for
diffusion, thus more
efficiency with
gas exchange.
•Reptiles have
amniotic eggs
with the embryo
surrounded by two
membranes.
•not all reptiles
lay eggs
(ovoviviparous)
•internal
fertilization
Reptiles have dry,
water-tight skin.
SCALES!
Reptiles are ectothermic.
(cold blooded)
CHARACTERISTICS OF BIRDS
•have feathers
•are endothermic (warm blooded)
•much higher body temperature
than mammals
Birds have
hollow bones
which lightens
the bone.
beaks, no
teeth
•Parental care of the young
•oviparous, hard shelled eggs
Birds have a 4 chambered heart
that is very efficient.
Birds have a super efficient respiratory
system. This system also aids in flight.
Characteristics of Mammals
•nurse young with
mammary glands
•care for young
diverse,
specialized
teeth
maintain high
body temperature
HAVE HAIR!
Mammals have 3 styles of reproduction
monotremes (oviparous)
placental
(viviparous)
marsupials
(viviparous)