Transcript Birds (cont.)

Characteristics of Vertebrates
• All vertebrates have a
backbone—
a series of structures that
surround and protect the
nerve cord, or spinal cord.
• The spinal cord connects all
the nerves in the body to the
brain.
• Bones that form a backbone
are called vertebrae.
Characteristics of Vertebrates (cont.)
• Vertebrates have well-developed organ
systems.
• All vertebrates have digestive systems
with 2 openings, circulatory systems that
move blood through the body, and
nervous systems that include brains.
• The five major groups of vertebrates are
fish, amphibians, reptiles, birds, and
mammals.
Fish
• Fish spend their entire lives in water and
have two important characteristics in
common: gills for absorbing oxygen gas
from water and paired fins for swimming.
Fish (cont.)
• Hagfish and lampreys lack jaws and are
in a group called jawless fish.
http://www.youtube.com/watch?v=letqkpG3b5Q
http://www.youtube.com/watch?v=IgrOK_831DY&N
R=1&feature=endscreen
Fish (cont.)
• Sharks, skates, and rays are
cartilaginous fish with skeletons made
of a tough, fibrous tissue called cartilage.
Cartilaginous Fish
• Store oil in liver to stay afloat
– Still denser than water and need to keep moving to
stay afloat
• Some must swim to maintain the flow of water
over their gills
– If they stop swimming, they will suffocate
• Others do not have to swim
– They can lie on the ocean floor and pump water
across their gills
Fish (cont.)
Trout, guppies, perch,
tuna, mackerel, and
thousands of other
species do not have
cartilaginous
skeletons. They have
bones and are
grouped together as
bony fish.
Amphibians
• Frogs, toads, and salamanders belong
to the class Amphibia.
• Most amphibians spend part of their lives
in water and part on land.
amphibian
from Greek amphi–, means “of both
kinds” and bios, means “life”
Young amphibians live in water and have gills
and fins. Through metamorphosis, most adults
develop lungs and limbs and live on land, near
water.
Amphibians (cont.)
• Lay eggs in water. These eggs do not
have hard protective coverings, or
shells.
• No scales
– Skin is thin, smooth, and moist
• Don’t drink water
– Absorb it through their skin
Reptiles
• Lizards, snakes, turtles, crocodiles, and
alligators belong to the class Reptilia.
Reptiles (cont.)
• All reptiles have waterproof skin that is
covered in scales.
Reptiles (cont.)
• Like amphibians,
most reptiles have
three-chambered
hearts.
Reptiles (cont.)
• Unlike amphibians,
lizards and other reptiles
have lungs throughout
their lives.
• Most reptiles lay fluidfilled eggs with leathery
shells that they lay on
land.
Endothermic: Warmblooded
(Birds and Mammals)
• Warm
blooded
(Endotherms)
Birds
• All birds are in the class Aves.
• Birds have lightweight bones, skin
covered with feathers and scales, two
legs, and two wings.
Birds (cont.)
Many birds can fly, and they have
stiff feathers that enable them to
move through the air.
Birds (cont.)
• Birds have toothless beaks and
digestive systems that include gizzards,
organs that help grind food into smaller
pieces.
Birds (cont.)
• Birds lay fluid-filled eggs with hard shells
and feed and care for their young.
Birds (cont.)
• Birds have many characteristics in
common with reptiles and are thought to
be descendants of dinosaurs
BIRDS
• Share some characteristics with reptiles
– Vertebrates
– Legs and feet covered by thick, dry
scales
– Skin around beak is scaly
– Amniotic egg
Birds have many Adaptations for flight
• High metabolism to get energy to fly
• Eat large amounts of food in proportion to
body weight
• Large eyes
• Air sacs – increase amount of oxygen
taken in
• Rapid heart rate - muscles get more
oxygen from blood
• Hollow bones
• Powerful flight muscles attached to a keel
Mammals
• Dogs, cats, goats, rats,
seals, whales, and humans
are among the many
vertebrates belonging to the
class Mammalia.
• All mammals have hair or
fur covering their bodies.
• Mammals tear and chew
their food using teeth.
Mammals (cont.)
• The most notable characteristic of
mammals is the presence of mammary
glands that produce milk which feeds
young mammals.
• Mammals are grouped according to how
their young develop.
Placental Mammals
– Develop inside mother’s
uterus
– Attached to mom by a
placenta-an organ that
transfers oxygen, nutrients
and waste
– Give birth to completely
developed live young
Monotremes- mammals that lay eggs
•
Just 2 species alive today
– Echidna
• Spine-covered with long
snouts
• Long sticky tongue for
catching ants & termites
– Platypus
• Swimming mammal
• Lives and feeds in rivers and
ponds
• Webbed feet, flat tail, flat,
rubbery bill to dig for food and
to dig long tunnels to lay eggs
Marsupials
– Mammals with a
pouch
– Give birth to live
young
– Shortly after birthdrag themselves
through mother’s fur
until they reach a
pouch in her
abdomen
– Mammary glands are
located inside pouch
Marsupials cont’
 Young
Kangaroos
(Joey) climbs
in, latches onto
a nipple, and
drinks milk