Exam 34: The Origin and Evolution of Vertebrates

Which of the following could be considered the most recent common ancestor of living tetrapods?

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

Use the following figure and information to answer the question. Fishes that have swim bladders can regulate their density and, thus, their buoyancy. There are two types of swim bladder: physostomous and physoclistous. The ancestral version is the physostomous version, in which the swim bladder is connected to the esophagus via a short tube (see the figure). The fish fills this version by swimming to the surface, taking gulps of air, and directing them into the swim bladder. Air is removed from this version by "belching." The physoclistous version is more derived and has lost its connection to the esophagus. Instead, gas enters and leaves the swim bladder via special circulatory mechanisms within the wall of the swim bladder. Which shark structure is closest in function to a swim bladder full of gas?

Living vertebrates can be divided into two major clades. Select the appropriate pair.

Vertebrates and tunicates share

Which of the following statements about the geographic distribution of marsupials is accurate?

The earliest known mineralized structures in vertebrates are associated with ________.

Many sentences in this chapter include the words "may suggest." This phrase indicates that ________.

Which of these might have been observed in the common ancestor of chondrichthyans and osteichthyans?

Use the following information to answer the question. While on an intersession course in tropical ecology, Kris pulls a large, snakelike organism from a burrow (the class was granted a collecting permit). The 1-meter-long organism has smooth skin, which appears to be segmented. It has two tiny eyes that are hard to see because they seem to be covered by skin. Kris brings it back to the lab at the field station, where it is a source of puzzlement to the class. Kris says that it is a giant oligochaete worm; Shaun suggests it is a legless amphibian; Kelly proposes it belongs to a snake species that is purely fossorial (lives in a burrow). The class decided to humanely euthanize the organism and subsequently dissect it. Having decided that it was probably not a reptile, two of their original hypotheses regarding its identity remained. Which of the following, if observed, should help them arrive at a conclusive answer?

Guppies are a common aquarium fish. They have internal fertilization, and females give birth to young that can swim immediately. Which of the following statements is correct?

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

Scientific views are based on evidence rather than an appeal to authority. Which of the following statements demonstrates a conclusion based on an appeal to authority?

A team of researchers has developed a poison that has proven effective against lamprey larvae in freshwater cultures. The poison is ingested and causes paralysis by detaching segmental muscles from the skeletal structures. The team wants to test the poison's effectiveness in streams flowing into Lake Michigan, but one critic worries about potential effects on lancelets, which are similar to lampreys in many ways. Why is this concern misplaced?

Use the following figure and information to answer the question. Fishes that have swim bladders can regulate their density and, thus, their buoyancy. There are two types of swim bladder: physostomous and physoclistous. The ancestral version is the physostomous version, in which the swim bladder is connected to the esophagus via a short tube (see the figure). The fish fills this version by swimming to the surface, taking gulps of air, and directing them into the swim bladder. Air is removed from this version by "belching." The physoclistous version is more derived and has lost its connection to the esophagus. Instead, gas enters and leaves the swim bladder via special circulatory mechanisms within the wall of the swim bladder. If a ray-finned fish is to both hover (remain stationary) in the water column and ventilate its gills effectively, then what other structure besides its swim bladder will it use?

At one time, birds held the same taxonomic rank as Reptilia and Mammalia. Now, however, they are considered as part of the reptile clade. Without this change, ________.

What group of mammals have (a) embryos that spend more time feeding through the placenta than the mother's nipples, (b) young that feed on milk, and (c) a prolonged period of maternal care after leaving the placenta?

During chordate evolution, what is the sequence (from earliest to most recent) in which the following structures arose?

At one time, Chondrichthyes were thought to have split off from other vertebrates before the evolution of bone. Now we have concluded that the Chondrichthyes split off after the evolution of bone had started. This change demonstrates ________.

With which of the following statements would a biologist be most inclined to agree?