The following five growth curves are lettered (A to E) corresponding to an expected growth curve if certain antibiotics were added to an exponentially growing culture of E.coli. The arrow indicates when antibiotics were added to the growing culture.

 

a) Pencicillin                                                                            1) 'A' Curve

b) Chloramphenicol                                                                2) 'B' Curve

c) Sulfoniamides                                                                     3) 'C' Curve

d) No antibiotics                                                                     4) 'D' Curve

                                                                                                  5) 'E' Curve