1) Which of the following is a characteristic of all chordates at some point during their life cycle?
A) jaws
B) post-anal tail

C) four-chambered heart
D) vertebrae

B

2) Why do adult urochordates (tunicates) lack notochords, even though larval urochordates have them? Larvae use notochords to ________.
A) aid in swimming; adults are sessile and thus no longer propel themselves
B) stiffen their bodies; in adults, the notochord is replaced by a column of bone

C) induce tissue differentiation; in adults, tissue is already differentiated
D) organize their nervous systems; adults' nervous systems are fully developed and do not change

A

3) If a tunicate's pharyngeal gill slits were suddenly blocked, the animal would have trouble ________.
A) respiring
B) feeding

C) moving
D) respiring and feeding

D

4) Chordate pharyngeal slits appear to have functioned first as ________.

A) the digestive system's opening
B) suspension-feeding devices
C) components of the jaw

D) sites of respiration

B

6) Which extant chordates are postulated to be most like the earliest chordates in appearance?

A) lancelets
B) adult tunicates
C) amphibians

D) chondrichthyans

A

7) Vertebrates and tunicates share ________.
A) jaws adapted for feeding
B) a high degree of cephalization
C) the formation of structures from the neural crest

D) a notochord and a dorsal, hollow nerve cord

D

8) All chordates studied to date, except tunicates, share a set of ________.

A) 13 Hox genes
B) 5 Dlx genes
C) 9 Otx genes

D) 7 FOXP2 genes

A

9) Which of the following characteristics is shared by a hagfish and a lamprey?

A) a rasping tongue
B) paired fins
C) jaws

D) a well-developed notochord

D

14) Why do skates and rays have flattened bodies, while sharks are torpedo shaped?
A) Sharks are more closely related to the tube-like lampreys than are skates and rays.
B) Skates and rays need enlarged pectoral fins to help them stay level in turbulent water, while sharks do not.
C) Skates and rays exchange gases across their skin and thus require a high surface-area-to- volume ratio, while sharks use gills to respire.
D) Sharks are streamlined for active swimming at mid-depths, while skates move about mostly on the ocean bed.

D

19) How did the evolution of the jaw contribute to diversification of early vertebrate lineages?

A) It allowed for smaller body size.
B) It was the first stage in the development of a bony skull.
C) It made additional food sources available.

D) It increased the surface area for respiration and feeding.

C

22) Which of these might have been observed in the common ancestor of chondrichthyans and osteichthyans?
A) a mineralized, bony skeleton
B) opercula

C) a spiral valve intestine
D) a swim bladder

A

23) Arrange these groups in order from most inclusive (most general) to least inclusive (most specific).
A) osteichthyans, gnathostomes, lobe-fins, tetrapods, amphibians
B) osteichthyans, gnathostomes, amphibians, tetrapods, lobe-fins

C) gnathostomes, osteichthyans, lobe-fins, tetrapods, amphibians

D) gnathostomes, osteichthyans, tetrapods, lobe-fins, amphibians

C

29) Which of the following characteristics allowed early gnathostomes to become successful predators?
A) fins stiffened with bone that increased maneuverability and improved gas exchange through the skin

B) fins stiffened with bone that increased maneuverability and improved gas exchange in the gills
C) lobe fins that allowed temporary access to land and improved gas exchange through the skin

D) lobe fins that allowed temporary access to land and improved gas exchange in the gills

B

34) A trend first observed in the evolution of the earliest tetrapods was ________.

A) the appearance of jaws
B) feet with digits
C) the mineralization of the endoskeleton

D) the amniotic egg

B

38) What is believed to be the most significant result of the evolution of the amniotic egg?

A) Tetrapods are no longer tied to the water for reproduction.
B) Tetrapods can now function with just lungs.
C) Newborns are much less dependent on their parents.

D) Embryos are protected from predators.

A

39) Which structure of the amniotic egg most closely surrounds the embryo?

A) the chorion
B) the yolk sac
C) the allantois

D) the amnion

D

40) The evolution of similar insulating skin coverings such as fur, hair, and feathers in mammals and birds is a result of ________.
A) shared ancestry
B) convergent evolution

C) homology
D) evolutionary divergence

B

43) Mammals and birds eat more often than reptiles. Which of the following traits shared by mammals and birds best explains this habit?
A) endothermy
B) ectothermy

C) amniotic egg
D) terrestrial habitat

A

44) Which characteristic is common to all the modern representatives of all major reptilian lineages (turtles, lepidosaurs, crocodilians, and birds)?
A) presence of teeth
B) presence of four walking limbs

C) ectothermy
D) presence of a notochord

D

45) Which of these are amniotes?

A) amphibians
B) fishes
C) turtles

D) lungfish

C

48) Which of these characteristics contributed the most to vertebrate success in relatively dry environments?
A) the shelled, amniotic egg
B) the ability to maintain a constant body temperature

C) two pairs of appendages
D) a four-chambered heart

A