Chapter 34

Front 1

Bilaterian

Back 1

member of a clade of animals with bilateral symmetry and three germ layers
ex: t-rex

Front 2

Deuterostrome

Back 2

organisms in which the anus develops from the blastopore, radial cleavage occurs in the embryo, and the body cavity develops as outpockets of mesodermal tissue

Front 3

Derived chordate characteristics

Back 3

1. Pharyngeal slits or clefts
a) In aquatic vertebrates (sharks, fish) – gas exchanging gills
b) In terrestrial vertebrates (reptiles, birds) – ear development and other structures in the head and neck
2. Dorsal, hollow nerve cord: unique to vertebrates; develops from ectoderm into drain and spinal cord
3. Notchord: long flexible rod present in chordate embryos, some adults, but usually replaced by a jointed skeleton for muscle attachment
4. Post-anal tail: a tail containing muscle and skeletal elements extending beyond the anus; provides propulsion in fish

Front 4

Characteristics of tunicates

Back 4

1. Oldest lineage of chordates
2. Resemble motile larva chordate
3. Swim to substrate and settle, then lose chordate characteristics

Front 5

Characteristics of lancelets

Back 5

1. Oldest retain the chordate traits
2. Musculature is similar to fish
3. Feed by burrowing into substrate with only their anterior end exposed

Front 6

Craniates

Back 6

chordate with well-defined heads
ex: hagfish

Front 7

Derived characteristics of craniates

Back 7

1. Gills slits in aquatic craniates
2. 2+ chambered heart; red blood cells with hemoglobin
3. Higher metabolism
4. Greater musculature
5. Kidneys

Front 8

Major classes of chordates

Back 8

1. Agnatha
2. Chondrichthyes
3. Osteichthyes
4. Amphibian
5. Reptilia
6. Aves
7. Mammalia

Front 9

Sharks General Characteristics

Back 9

1. Cartilaginous skeleton impregnated with Ca streamlines body built for speed, not very maneuverable through
2. Predatory
3. 750 spp mostly marine
4. Buoyancy due to a large oily liver

Front 10

Sharks Nutrition

Back 10

1. Large sharks tend to be suspension-feeders
2. Multiple rows of self-regenerating teeth
3. Short digestive tract with a spiral valve – increases surface area while slowing digestion

Front 11

Sharks Sensory Organs

Back 11

1. Electroreceptor system
2. Sharp senses of vision and smell
3. Lateral line system

Front 12

Sharks Reproduction

Back 12

1. Internal fertilization
2. Male claspers transfer sperm into the female reproductive tract
3. Female lay eggs
4. Eggs hatch in uterus
5. Young are born live

Front 13

Fish

Back 13

A) Ray finned fishes
1. Fins are supported by long, flexible rays modified for defense and maneuvering
B) Lobe finned fishes
1. In pectoral and levic fins, rod-shaped are surrounded by a thick layer of muscle

Front 14

Tetrapods Derived Characteristics

Back 14

a) four legs- limbs with digits
b) fusion of pelvic girdle to spine
c) pharyngeal clefts giving rise to parts of the ear and other structures (not gills)
d) ears adapted to airborne sounds
ex: acanthostega

Front 15

Tetrapod Origins

Back 15

a) body plan- modified version of lobe-finned lung fish
b) adapted to aquatic/terrestrial habitats
c) most spp require water for reproduction
ex: ichthyostega

Front 16

Amphibia General Characteristics

Back 16

a) some spp strictly aquatic, some terrestrial
b) require water for reproduction
c) developmental metamorphosis
d) moist skin allows for gas exchange
ex: tiger salamander

Front 17

Amphibia Reproduction

Back 17

a) external fertilization
b) eggs laid in water to prevent desiccation
c) amphibians are oviparous, ovoviviparous, or viviparous
ex: frogs

Front 18

Amniotes General Characteristics

Back 18

a) organisms which begin inside an amniotic egg; contains specialized membrane to protect embryo
b) include reptiles, birds, and mammals
c) specialized membrane nutrition, gas exchange, and waste removal
d) shell prevents dehydration
i) reptile= leathery shell
ii) bird= calcaneous shell
ex: turtle hatching

Front 19

Reptilia General Characteristics

Back 19

a) earliest reptiles emerged 320 mya
b) do not require water for reproduction
c) no developmental metamorphosis
d) keratinized scales are water proof; prevents dehydration
e) ectothermic: cannot maintain constant body temperature; dependent upon external heat

Front 20

Reptilia Reproduction

Back 20

a) internal fertilization
b) eggs laid on land due to amniotic egg
c) oviparous and viviparous

Front 21

Reptilia Origins

Back 21

diapsids: marine reptiles, pterosaurs, and dinosaurs
i) ornithischians: sluggish, cold blooded
ii) saurischians: active, warm blooded

Front 22

Reptilia: Testudine

Back 22

-turtles, tortoises
a) upper and lower shell fused to skeleton
b) carnivorous and herbivores
c) inhabit dry, moist, and aquatic habitats

Front 23

Reptilia: Crocodilia

Back 23

-crocodiles, alligators
a) upturned nose for aquatic existence
b) carnivorous
c) inhabit warm, aquatic habitats

Front 24

Reptilia: Lepidosaurus

Back 24

-squamate (snakes)
a) adapted to predation by chemo and heat receptors and sensitivity to vibrations
b) kill by venom or constriction

Front 25

Aves General Characteristics

Back 25

a) internal fertilization and oviparous (egg layers)
b) 4 chambered heart
c) endothermic- maintains constant body temperature; dependent on internal heat

Front 26

Adaptation for flight

Back 26

1) wings and feathers (2)
2) pneumatic bones (air filled bones)
3) keeled sternum and flight muscles (2)
4) four chambered heart and endothermic
5) well developed vision centers (brain)
6) reduction of urogenital (urinating ) organs

Front 27

Aves origins

Back 27

a) evolved from the theropod dinosaurs (T.Rex)
b) feathers evolved before flight (purpose)
c) archaeopteryx emeerged 150 mya