The island fox shares a common ancestor with the gray fox, Urocyon cinereoargenteus, which is found on the mainland.

A. Both species have similar coloration and a diploid chromosome number of 66.
B. One structural difference between the two species is the reduced size of the island fox, a feature known as dwarfism.
C. The various island subspecies also differ from each other in size, number of tail vertebrae, and other characteristics.
D. The phylogenetic tree below shows the evolutionary relationships between the island fox subspecies and the gray fox.
E. Drag the labels to their appropriate locations on the tree.

Penicillin is hydrolyzed and thereby rendered inactive by penicillinase (also known as β-lactamase), an enzyme present in some resistant bacteria. the mass of this enzyme in staphylococcus aureus is 29.6 kd. the amount of penicillin hydrolyzed in 1 minute in a 10-ml solution containing 10-9 g of purified penicillinase was measured as a function of the concentration of penicillin. assume that the concentration of penicillin does not change appreciably during the assay. penicillin(μm) amount hydrolyzed(nmol) 1 0.11 3 0.25 5 0.34 10 0.45 30 0.58 50 0.61 (a) plot v0 versus [s] and 1/v0 versus 1/[s] for these data. does penicillinase appear to obey michaelis-menten kinetics? if so, what is the value of km? (b) what is the value of vmax? (c) what is the turnover number of penicillinase under these experimental conditions? assume one active site per enzyme molecule.