Mastering Bio: Chapter 34

Which of the following structures do vertebrates and tunicates both possess?

a notochord and a dorsal hollow nerve cord

Which of the following organisms is considered the most recent common ancestor of living tetrapods?

a sturdy-finned, shallow-water lobe fun whose appendages had skeletal supports similar to those of terrestrial vertebrates

Which of the following statements best describes the overall process of descent with modification?

a trait present in an ancestral organism is modified by natural selection over time in descendants of that ancestor

Based on this phylogeny, which vertebrae groups would you expect to have lungs or lung derivatives?

actinopterygii actinistia dipnoi amphibia reptilia mammalia

Which choice is a characteristic only of truly terrestrial animals with no need to return to water at any stage of the life cycle?

amniotic eggs

Most members of the which of the following groups are most closely associated with a wet (or moist) environment?

amphibians

The diagnostic feature of Chondrichthyes is:

an endoskeleton of cartilage

Which of the following are the only extant animals that descended directly from dinosaurs?

birds

Jaws evolved:

by modification of the skeletal rods that previously supported the anterior pharyngeal slits

At one time, Chondrichthyes were thought to have diverged from other vertebrates before the evolution of bone. Now we have concluded that the Chondrichthyes diverged after the evolution of bone had started. What does this change demonstrate about the evolution of fishes?

characteristics can be lost in evolution

The evolution of similar insulating skin coverings such as fur, hair, and feathers in mammals and birds is a result of which of the following evolutionary processes?

convergent evolution

Mammals and birds eat more often than reptiles. Which of the following traits shared by mammals and bird best explains this habit?

endothermy

What group of mammals display the following characteristics? -embryos that spend more time feeding through the placenta than the mother's nipples -young that feed on milk -a prolonged period of maternal care after leaving the placenta

eutheria

Which of the following was a trend first observed in the evolution of the earliest tetrapods?

feet with digits

Ancient fossils that seem to be an intermediate stage in the evolution from fish to tetrapods had which of the following characteristics?

fins and scales like a fish but ribs to support the body and bone structure in the front limb like tetrapods

Which of the following groups includes the greatest number of organisms?

gnathostomes

Which of the following characteristics is exhibited by both monotremes and marsupials?

have some embryonic development outside the uterus

In which of the following ways did the evolution of the jaw contribute to diversification of early vertebrate lineages?

it made additional food sources available

Which extant chordates are most like the earliest chordates in appearance?

lancelets

There are 3 major groups of mammals, categorized on the basis of their ________________

method of reproduction

A new species of aquatic chordate is discovered that closely resembles an ancient form. It has the following characteristics: external armor of bony plates, no paired lateral fins, and a suspension-feeding mode of nutrition. In addition to these, which of the following characteristics is it most likely to exhibit?

no jaws

Which of the following is a characteristic of all chordates at some point during their life cycle?

post-anal tail

Which of the following statements is correct regarding lancelets?

recent work in molecular systematics supports the hypothesis that lancelets are the basal clade of chordates

In a typical ray-finned fish, the swim bladder allows individuals to perform which of the following processes?

remain neutrally buoyant

In early chordates, the primitive pharyngeal slits carried out which of the following functions?

suspension-feeding devices

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

tetrapods are no linger tied to the water for reproduction

Which of these characteristics contributed the most to vertebrate success in relatively dry environments?

the shelled, amniotic egg

Which of these groups or organisms are amniotes?

turtles

All of the following represent diagnostic features of chordates except for which one?

vertebrae

In the phylogenetic tree shown, which of the following are shared ancestral characters for members of the turtle-leopard group?

vertebral column; four limbs