Ch. 34

Question 1

Chordates are bilaterian animals that belong to the clade of animals known as ________.

Answer 1

Deuterostomia.

Question 2

Chordates comprise all vertebrates and 2 groups of invertebrates:

Answer 2

Urochordates and Cephalochordates.

Question 3

4 Key characters of chordates:

Answer 3

1. Notochord
2. Dorsal, hollow nerve chord
3. Pharyngeal slits or cleft
4. Muscular, post-anal tail

Question 4

The __________ is a longitudinal, flexible rod between the digestive tube and nerve chord.

Answer 4

Notochord.

Question 5

The ________ develops into the Central Nervous System: the brain and the spinal chord.

Answer 5

Nerve Chord.

Question 6

Functions of the pharyngeal slits (3):

Answer 6

• Suspension-feeding structures in many invertebrate chordates
• gas exchange in vertebrates (except vertebrates with limbs, the tetrapods)
• Develop into parts of the ear, and neck in tetrapods

Question 7

________ (Urochordata) are more closely related to other chordates than are lancelets.

Answer 7

Tunicates.

Question 8

________ share some characteristics: a skull, a brain, eyes and other sensory organs.

Answer 8

Craniates.

Question 9

One feature unique to craniates is the _________, a collection of cells near the dorsal–these give rise to a variety of structures, including some of the bones and cartilage of the skull.

Answer 9

Neural Crest.

Question 10

_______ were the first vertebrates with mineralized skeletal elements in their mouth and pharynx.

Answer 10

Conodonts.

Question 11

_______ are vertebrates that have jaws; include: sharks, ray-finned fishes, lobe-finned fishes, amphibians, reptiles, birds and mammals.

Answer 11

Gnathostomes.

Question 12

In aquatic gnathostomes, the ________, which is sensitive to vibrations is present.

Answer 12

Lateral Line System.

Question 13

The earliest gnathostomes in the fossil record are an extinct lineage of armored vertebrates called ________.

Answer 13

Placoderms.

Question 14

Group of jawed vertebrates that radiated during the Silurian and Devonian periods (444 to 359 MYA)?

Answer 14

Acanthodians.

Question 15

__________ (sharks, rays, relatives) have a skeleton composed primarily of cartilage.

Answer 15

Chondrichthyans.

Question 16

________: eggs that hatch outside the mother’s body.

Answer 16

Oviparous.

Question 17

________: The embryo develops within the uterus and is nourished in the egg yolk.

Answer 17

Ovoviviparous.

Question 18

_______: The embryo develops within the uterus and is nourished through a yolk sac placenta from the mother’s blood.

Answer 18

Viviparous.

Question 19

Nearly all living _______ have bony endoskeleton; include bony fish and tetrapods.

Answer 19

Osteichthyans.

Question 20

Most fishes breathe by drawing water over gills protected by an ________.

Answer 20

Operculum.

Question 21

Fish control their buoyancy with an air sac known as a ___________.

Answer 21

Swim Bladder.

Question 22

The ______ (Sarcopterygii) have muscular pelvic and pectoral fins.

Answer 22

Lobe-Fins

Question 23

Tetrapods have specific adaptations (5):

Answer 23

• 4 limbs and feet w/ digits
• Neck, which allows separate movement of the head
• Fusion of the pelvic girdle to the backbone
• The absence of gills
• Ears for detecting airborne sounds

Question 24

________ are a group of tetrapods whose living members are the reptiles, including birds and mammals.

Answer 24

Amniotes.

Question 25

Most reptiles are _______, absorbing external heat as the main source of body heat.

Answer 25

Ectothermic.

Question 26

Birds are _________, capable of keeping the body warm through metabolism.

Answer 26

Endothermic.

Question 27

Birds descended from the group, _______, whom were bipedal carnivores.

Answer 27

Theropods.

Question 28

______ are amniotes that have hair and produce milk.

Answer 28

Mammals.

Question 29

Mammals have (5):

Answer 29

• Mammary glands, which produce milk
• Hair
• A higher metabolic rate, due to endothermy
• A larger brain than other vertebrates of equivalent size
• Differentiated teeth

Question 30

Mammals evolved from ________.

Answer 30

Synapsids.

Question 31

________ are a small group of egg-laying mammals consisting of echidnas and the platypus.

Answer 31

Monotremes.

Question 32

________ include opossums, kangaroos, and koalas.

Answer 32

Marsupials.

Question 33

The embryo develops within a ________ in the mother’s uterus.

Answer 33

Placenta.