20. Three common characteristics of adult vertebrates are

Question

a. skull, notochord, and complex organ system
b. backbone, segmentation, and open circulatory system
c. two pairs of jointed appendages, cephalization, and internal skeleton
d. hydrostatic skeleton, bilateral symmetry, and true coelom
D?

24. A backbone, gills, and single-loop blood circulation are characteristics of
a. cartilaginous fish
b. gelatinous fish
c. jawless fishes
d. all of the above
D?

31. Endothermic metabolism, complete ventricle division in heart, and a very efficient respiratory system are characteristics of
a. reptiles
b. birds
c. amphibians
d. fish
B?

-MC