Chordates (E2)

Question 1

Characteristics of Chordata

Answer 1

Notochord
Pharyngeal Slits or Clefts
Dorsal, Hollow Nerve Cord
Post-Anal Tail

Question 2

Cephalochordate

Answer 2

Lancelets
Undergo metamorphosis
Retain all chordate traits into adulthood

Question 3

Urochordata

Answer 3

Tunicates
Undergoes metamorphosis, tail and notochord are reabsorbed, and the nervous system degenerates

Question 4

Characteristics of Vertebrates

Answer 4

Development of skull and backbone composed of vertebrae
Neural Crest - gives rise to teeth, bones, cartilage of the skull, neurons, sensory capsules.

Question 5

Myxini and Petromyzontida

Answer 5

Hagfish and Lampreys
Only vertebrates that lack a jaw and backbone
Rudimentary vertebrae made of cartilage

Question 6

Gnathostomes Characteristics

Answer 6

Vertebrates with Jaws
Duplication of Hox genes
Enlarged forebrain
Lateral line system

Question 7

Chondrichthyans

Answer 7

Cartilage fish
Oviparous - lay eggs that hatch outside the mother’s body
Ovoviviparous - retain fertilized eggs in the oviduct, nourished by egg yolk
Viviparous - young develop in the uterus, nourishment from the mother’s blood (placenta)

Question 8

Osteichthyans

Answer 8

Hard bony endoskeleton w/ hard calcium phosphate matrix
Breath with 4-5 pairs of gills
Maintain buoyancy with swim bladder

Question 9

Tetrapod characteristics

Answer 9

Vertebrates
Limbs with digits, head separated from the body by a neck, pelvis bones are fused to backbone
pharyngeal clefts give rise to ears and other structures

Question 10

Characteristics of Amniotes

Answer 10

Tetrapod that include reptiles, mammals, and birds.
Have an amniotic egg - contains four different membranes around the egg (amnion, chorion, yolk sac, allantois)
Ventilate their lunges with a rib cage

Question 11

Reptiles

Answer 11

Have scales that contain keratin, protecting the skin from damage
Lay their shelled eggs on land (shell prevents drying out)
Ectothermic, they absorb external heat as the main source of body heat
Birds are endothermic

Question 12

Bird Characteristics

Answer 12

Flight
Lack of Urinary Bladder
One ovary
Small gonads
Toothless
Endothermic
4 chambered heart

Question 13

Mammal Characteristics

Answer 13

Have mammary glands that produce milk
Kidneys
Endothermic and high metabolic rate
Efficient respiratory and circulatory system (4 chambered heart)
Heterodontric - have different kinds of teeth

Question 14

Monotremes

Answer 14

Mammals - platypus, echidnas
Lay eggs, produce milk, and have hair
Found in Australia and New Guinea

Question 15

Marsupials

Answer 15

North and South America and Australia, opossums, kangaroos, koalas
High metabolic rates, give birth to live young, and have nipples that provide milk
Has a placenta, but is born early in embryonic development
Nurse and finish development in the marsupium

Question 16

Eutherians

Answer 16

Placental Mammals
High metabolic rates, give birth to live young, have nipples that provide milk
Has a placenta and has a longer pregnancy tahn marsupials
Complete embryonic development in the uterus.

Question 17

Primate Characteristics

Answer 17

Hands and feet designed for grasping, digits have flat nails, skin ridges on fingers, large brain, short jaws, complex social behavior
opposable thumbs that can move separately from fingers.