Exam 34: The Origin and Evolution of Vertebrates

Use the following information to answer the question. Due to its system of air sacs connected to the lungs, the respiratory system of birds is arguably the most effective respiratory system of all air-breathers. Upon inhalation, air first flows into posterior air sacs, then into the lungs, and then into anterior air sacs on the way to being exhaled. Thus, there is one-way flow of air through the lungs, along thousands of tubules called parabronchi. The one-way flow of air along parabronchi makes what type of gas exchange mechanism possible, at least theoretically?

Chordate pharyngeal slits appear to have functioned first as ________.

Which characteristic is common to all the modern representatives of all major reptilian lineages (turtles, lepidosaurs, crocodilians, and birds)?

Female birds lay their eggs, thereby facilitating flight by reducing weight. Which "strategy" seems most likely for female bats to use to achieve the same goal?

Jaws first occurred in which extant group of fishes?

Vertebrates and tunicates share ________.

As hominins diverged from other primates, which of the following appeared first?

Which of the following statements would be most acceptable to most zoologists?

On the back of your skull you can feel a small bump, below which is an opening where the spinal cord enters the skull. The location of this opening toward the bottom of the skull is significant in evolutionary biology for what reason?

Why do adult urochordates (tunicates) lack notochords, even though larval urochordates have them? Larvae use notochords to ________.

Which clade does not include humans?

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

Birds are descended from species that laid eggs in water. It could be argued that embryos of birds still develop in water because ________.

Suppose, while out camping in a forest, you found a chordate with a long, slender, limbless body slithering across the ground near your tent. This critter could be ________.

It is believed that the coelacanths and lungfish represent a crucial link between other fishes and tetrapods. What is the major feature in these fish in support of this hypothesis?

Which of the following is the most inclusive (most general) group in which all of the members have fully opposable thumbs?

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. The presence of a swim bladder allows the typical ray-finned fish to stop swimming and still ________.

Which of the following types of evidence would be useful in understanding if the impact of a comet caused the extinction of the dinosaurs?

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

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