32. Vertebrates

Which of the following animals is an amphibian?

Habitat loss, the spread of a fungal disease, climate change, and pollution are causing severe population declines and extinction in __________.

Vertebrates and tunicates sharea. jaws adapted for feeding.b. a high degree of cephalization.c. an endoskeleton that includes a skull.d. a notochord and a dorsal, hollow nerve cord.

True or false? Both echinoderms and vertebrates have endoskeletons. Explain.

Living vertebrates can be divided into two major clades. Select the appropriate pair.a. the chordates and the tetrapodsb. the urochordates and the cephalochordatesc. the cyclostomes and the gnathostomesd. the marsupials and the eutherians

What trait(s) characterize the vertebrates?a. vertebrae and a craniumb. jaws and a spinal cordc. bony endoskeletond. notochord and post-anal tail

"In the chordate phylogenetic tree below, fill in the shared derived character that defines each clade.a. Notochordb. Vertebral columnc. Jawsd. Bony skeletone. Four limbsf. Amniotic eggg. Hairs"

What trait(s) characterize the vertebrates?a. vertebrae and a craniumb. jaws and a spinal cordc. bony endoskeletond. notochord and post-anal tail

A lamprey, a shark, a lizard, and a rabbit share all the following characteristics excepta. pharyngeal slits in the embryo or adult.b. vertebrae.c. hinged jaws.d. a dorsal, hollow nerve cord.

In Figure 34.25, which of the following is the sister taxon to the archosaurs? (A) synapsids (B) crocodilians (C) turtles (D) lepidosaurs

Which clade does not include humans?a. synapsidsb. lobe-finsc. diapsidsd. osteichthyans

Two black female mice are crossed with a brown male. In several litters, female I produced 9 black offspring and 7 brown; female II produced 57 black offspring. What deductions can you make about the inheritance of black and brown coat color in mice? What are the genotypes of the parents?

Why were the Tiktaalik fossils an exciting discovery for scientists studying tetrapod evolution?a. They are the earliest frog-like animal discovered to date.b. They show that tetrapods successfully colonized land much earlier than previously thought.c. They have a roughly equal combination of fishlike and tetrapod-like characteristics.d. They demonstrate conclusively that limbs evolved as lobe-fins dragged themselves from pond to pond during droughts.

Which of the following could be considered the most recent common ancestor of living tetrapods?a. a sturdy-finned, shallow-water lobe-fin whose appendages had skeletal supports similar to those of terrestrial vertebratesb. an armored, jawed placoderm with two pairs of appendagesc. an early ray-finned fish that developed bony skeletal supports in its paired finsd. a salamander that had legs supported by a bony skeleton but moved with the side-to-side bending typical of fishes

To estimate the relative abundance of the major phyla, calculate how many named species of arthropods, mollusks, and nematode worms exist per named species of chordate (the phylum containing vertebrates, including humans; see Table 30.1). Do you think these calculations are likely to be underestimates or overestimates? Why?