CH 34

Question 1

Phylum Chordata

Answer 1

• bilateral deuterostomes
  -2 invertebrate groups and 1 vertebrate group
• 4 derived traits: notochord, dorsal hollow nerve cord, pharyngeal slits, and muscular post-anal tail

Question 2

Cephalochordata

Answer 2

• lancelets: marine suspension feeders
• life long chordate characteristics

Question 3

Urochordata “tail chord”

Answer 3

• marine tunicates and sea squirts
• adult has pharyngeal slits for suspension

Question 4

Craniata: “head”

Answer 4

• head with brain, eyes, other sensory organs
• other derived traits:
• 2 sets of hox genes (earlier animals)
• high metabolism and muscle than lower chordates
• heart with 2+ chambers
  -RBCs with hemoglobin
• kidneys

Question 5

Myxini: “slimy”

Answer 5

• hagfishes
  -cartilaginous skull and rod
• no jaws, but teeth like structures
• small brain and sensory organs

Question 6

Vertebrata: “joint of the spine”

Answer 6

-craniates with a backbone:
-successful because of complex organ systems and endoskeleton that allows for lots of growth
- derived characteristics;
- bony or cartilaginous vertebrae protect spinal cord
- well developed skull

Question 7

Petromyzontida “stone suckers”

Answer 7

• jawless marine & fw lampreys
• cartilaginous skeleton:
  -small prong like vertebrae along notochord

Question 8

Origins of bone and teeth

Answer 8

• after lampreys diverged: mineralized skeletons
• probably began with mouthparts:
• then skull and eventually entire endoskeleton

Question 10

Gnathostoma “jawed mouth”

Answer 10

• vertebrates with hinged jaws (grip and tear)
• likely from pharyngeal slits
• other characters:
• 4 sets of hox genes
• enlarged forebrain: olfaction & vision
  -aquatic: lateral lines, paired fins and tail

Question 11

Chondrichthyes: “cartilage fish”

Answer 11

• elasmobranchs and chimaeras
• cartilaginous skeleton:
• some mineralization (teeth and scales)
• external and internal fertilization and dev.
• sharks
  -rays and skates
• chimaeras

Question 12

Osteichthyes “bony fish”

Answer 12

• bony fish and tetrapods:
• calcium phosphate endoskeleton
• aquatic orgs: bony scales, swim bladder, and slime coat
• external and internal fert and dev.

Question 13

Actinopterygii “ray wing”

Answer 13

• fw and marine ray finned fishes
• fins have bony rays
• economically and ecologically important

Question 14

Sarcopterygii “fleshy wing”

Answer 14

• lobe finned: muscular pelvic and pectoral fins
• coelacanths, lungfishes and tetrapods

Question 15

Actinistia “ hollow spine”

Answer 15

-coelocanths

Question 16

Dipnoi “double breathing”

Answer 16

• lungfishes:
  6 spp in stagnant fw
• use lungs to gulp air and has gills

Question 17

Tetrapoda “4 feet”

Answer 17

• gnathostomes with 4 limbs and feet with digits:
• support weight on land
• other adaptations for terrestrial life:
• pelvic girdle fused to backbone
• neck that moves up/down, and side to side

Question 18

Amphibia “both ways of life”

Answer 18

• first terrestrial group
• life is tied to water:
• moist skin (& lungs in some) for gas exchange
  -most: external fert and dev
• v sensitive to pollutants

Question 19

Order urodela

Answer 19

• tailed ones
• salamanders and newts

Question 20

Order apoda

Answer 20

• without legs
• tropical caecilians
• look like earthworms

Question 21

Order Anura

Answer 21

• without tails
• frogs and toads
• specialized hopping legs

Question 22

Amniotes

Answer 22

• liquid collection vessel
• tetrapods with terrestrially adapted eggs
• amniotic egg with 4 extra embryonic membranes
• other adaptations:
• relatively impermeable keratinized skin
• rib cage to ventilate lungs

Question 23

Reptilia

Answer 23

• “ creeping”
• highly adapted for terrestrial life:
• thick keratinized scales
• internal fertilization and lay shelled eggs on land
• except for birds, are ectothermic
• appeared 310 mya
• turtles, lepidosaurs, archosaurs, birds

Question 24

Birds are. . .

Answer 24

• modified for flight:
• wings feathers, flight muscles
• air sacs in bone
• no bladder or teeth, small gonads
  -highly efficient:
  -endothermic
• specialized lungs
• excellent vision and big brain

Question 25

Mammalia “breasts”

Answer 25

- 3 lineages Derived traits: - mammary glands - hair/fur - 3 inner ear bones - placenta - diaphragm - endothermic; - internal fertilization & parental care - large brains - specialized teeth

Question 26

3 mammalia lineages

Answer 26

- monotremes - marsupials - eutherians

Question 27

4 extraembryonic membranes for amniotes

Answer 27

-amnion, chorion, allantois, yolk sac