Download BIO102-Biodiversity Part2 Ch.35

Characteristics of Animal Phyla
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A. Porifera (sponges)
1. Full of pores (holes)
2. No specialized cells, tissues…
3. Aquatic
4. Get O2 by diffusion
5. Filter feeders; Adults can’t move
6. soft & rough sponges
Porifera
B. Cnidaria (Coelenterates)
1. Hollow body with 1 opening
2. No organs or systems
3. Aquatic
4. O2 diffuses into cells
5. Tentacles with stinging cells
6. jellyfish, coral, hydra, anemones
Cnidarians
C. Platyhelminthes (Flatworms)
1. Thin flattened body with 1
opening tube (Anus = mouth)
2. Some specialized tissues - no
organ systems
3. Some are parasitic and some
are free-living (aquatic)
4. O2 diffuses into cells
5. Up to 30 feet long
6. Planaria & tapeworms.
Platyhelminthes
D. Phylum Nematoda (Roundworms)
1. Tubular body with 2 openings
(Anus & Mouth)
2. Some specialized tissues;
longitudinal muscles
3. Most are parasitic
4. Oxygen diffuses through skin
5. Filarial worms = elephantiasis
6. Ascaris & Trichinia
Nematoda
E. Annelida (Segmented Worms)
1. Segmented body with 2
openings
2. Organs and systems: circular and
longitudinal muscles
3. Aquatic and terrestrial
4. O2 diffuses through moist skin
5. Hermaphrodites (both sexes)
6. Earthworms & leeches
Annelida
F. Mollusca
1. Soft bodies with 2 openings
2. Many organs and systems
3. terrestrial and aquatic
4. Get O2 through gills
5. Have shells or tentacles for
protection
6. Clams, snails, Oysters, Squid,
Slugs, and octopus.
Mollusca
G. Echinodermata
1. Spiny skin
2. Organs & systems
3. Aquatic
4. O2 taken in through tiny gills
5. Radial symmetry; Water vascular
system for movement (suction cups)
6. Sea stars, sand dollars, sea
urchins.
Echinodermata
H. Arthropoda
1. Segmented bodies with jointed
appendages (legs)
2. organs & systems
3. terrestrial & aquatic
4. Get O2 through gills, book lungs,
tracheal tubes
5. Exoskeleton surrounding body
6. millipedes, centipedes, insects,
crustaceans, arachnids
Arthropods
5. Five Classes of Arthropods
a. Millipedes- Round + 2 leg pr/segment
b. Centipedes – Flat + 1 leg pr/segment
c. Crustaceans
1.) Aquatic with gills
2.) 2 pair of antenae
3.) Examples = Crayfish,
lobster, shrimp, and crabs.
d. Arachnida
1.) 2 body segments
2.) 4 pair of legs
3.) Examples = Ticks, mites, spiders
e. Insecta
1.) 3 body segments
2.) 3 pair of legs
3.) Some have wings
4.) Many go through metamorphosis
(a change in body form)
I. Phylum Chordata
1. nerve cord, gill slits, tail, and
notochord at some point
during development;
2. specialized organs & systems
3. Aquatic & terrestrial
4. Get O2 through gills or lungs
5. most have backbones
6. lamprey, fish, sharks, reptiles,
amphibians,, birds, mammals
Chordata
Vertebrates
Chapter 35
Subphylum Vertebrata
Key characteristics:
1. Vertebral column – Encloses and
protects the dorsal nerve cord
2. Head – sensory organs
3. internal organs
4. endoskeleton – makes possible great size
& movements
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Subphylum Vertebrata
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Subphylum Vertebrata
The first vertebrates appeared in the oceans
about half a billion years ago
-Jawed fishes soon became dominant
-Their descendants, the amphibians,
invaded the land
-Reptiles replaced them as the dominant
land vertebrates
-Gave rise to birds and mammals
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Fishes
Fishes are the most diverse vertebrate group
-Over half of all vertebrates
Includes:
Agnatha - jawless fish
Chondrichthyes – sharks
Osteichthyes - bony fish
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Fishes
Fishes have the following characteristics
1. Vertebral column
2. Jaws and paired appendages
3. Internal gills
4. Single-loop blood circulation
5. Nutritional deficiencies
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Amphibians (Amphibia)
Amphibians are damp-skinned vertebrates
-First vertebrates to walk on land
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Amphibians
Amphibians have several key characteristics
1. Legs
2. Lungs
3. Cutaneous respiration
4. Partially divided heart
5. Eggs in Water
Includes frogs & toads, salamanders, caecilians30
History of Amphibians
Successful invasion of lands by vertebrates
required several adaptations
1. Legs to support body’s weight
2. Lungs to extract oxygen from air
3. Redesigned heart to drive larger muscles
4. Reproduction in H2O to prevent egg drying
5. System to prevent whole body desiccation
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Modern Amphibians
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Reptiles (Reptilia)
Reptiles dominated earth for 250 million years
key features
1. Amniotic eggs, which are watertight
2. Dry skin, which covers body and
prevents water loss
3. Thoracic breathing, which increases
lung capacity
4. ectothermic, cold-blooded
Includes turtles & tortoises, tuataras, lizards &
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snakes, crocodiles & alligators
Modern Reptiles
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Birds (Aves)
Birds are the most diverse of all land vertebrates
-28 orders, 166 families, about 8600 species
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Birds
Birds still retain many reptilian traits
-Amniotic eggs and scales on legs
Two major traits distinguish them
1. Feathers
-Provide lift for flight and conserve heat
2. Flight skeleton
-Bones are thin and hollow
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Adaptations providing energy for flight
1. Efficient respiration
-Air passes all the way through lungs in a
single direction
2. Efficient circulation
-Muscles receive fully oxygenated blood
-Rapid heartbeat
3. Endothermy
-Body temperature (40-42oC) permits
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higher metabolic rate
Mammals (Mammalia)
There are about 4500 species of mammals
(class Mammalia)
-includes monotremes, marsupials, placentals
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Mammals
Key characteristics:
1. Hair
-Insulation, camouflage, sensory structure
2. Mammary glands
-secrete milk
3. endothermic (warm-blooded)
-depends on more efficient circulatory
system
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