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? its operculum
If a tunicate's pharyngeal gill slits were blocked by a foreign object, which of the following processes would the organism have trouble performing? respiring and feeding
Which of these groups of organisms are amniotes? turtles
The ancestors of amniotes laid eggs in water. It could be argued that embryos of amniotes still develop in water for which of the following reasons? the amnion encases each embryo in water
Which of the following characteristics is exhibited by both monotremes and marsupials? have some embryonic development outside the uterus
While hiking in a tropical rainforest, you find a large, snakelike organism that is 1-meter-long, has smooth skin, and appears to be segmented. You think it might be a snake or an amphibian. Which of the following characteristics, if observed, should help you arrive at a conclusive answer? presence of scales
Which extant chordates are most like the earliest chordates in appearance? lancelets
In vertebrates, the earliest known mineralized structures were associated with body parts involved in which of the following processes? feeding
Mammals and birds eat more often than reptiles. Which of the following traits shared by mammals and birds best explains this habit? B) amniotic egg
Suppose, while out camping in a forest, you found a chordate with a long, slender, limbless body slithering across the ground near your tent. The organism is most likely ________. an amphibian
During chordate evolution, which of the following structures arose first? paired fins
Which structure of the amniotic egg most closely surrounds the embryo? the amnion
The respiratory system of birds is one of the most effective respiratory systems of all air-breathing organisms, due to its system of air sacs connected to the lungs. Which of the following can be inferred about the air sacs given the observation that they are neither thin nor highly vascularized? They are not efficient sites of gas exchange between air and blood.
Which of these characteristics contributed the most to vertebrate success in relatively dry environments? the shelled, amniotic egg
Which of the following analyses would best help to determine if a fossil represents a reptile or a mammal? examine the teeth
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 statements about the geographic distribution of marsupials is accurate? they occur in Australia and the Americas
Which of these traits is most strongly associated with the evolution of bipedalism? repositioning of foramen magnum
Which of the following organisms is considered the most recent common ancestor of living tetrapods? a sturdy-finned, shallow-water lobe-fin whose appendages had skeletal supports similar to those of terrestrial vertebrates