Question

in a study of the evolution of dpta and dptb - diptericin genes encoding antimicrobial peptides that combat pathogens and foster beneficial microbes in fruit flies (drosophila) - researchers assessed drosophila melanogaster resistance to pathogenic infections by providencia rettgeri and acetobacter sicerae. bacteria common in the flies environments. subjects included flies identified by mutations silencing dpta, dptb, or both dpta and dptb (termed types a, b, and ab, respectively). in conjunction with the observation that resistance to p. rettgeri correlates with dpta activity but is not significantly affected by dptb activity, data in the graph of survival rates post - 1 - stercus infection suggest that. which completion of the text is best supported by data in the graph? a) dpta confers defense against a. sicerae regardless of the presence of dptb. b) dptb protects against only one bacteria species, whereas dpta protects against multiple species. c) dptb may have developed as a specific defense against a. sicerae. d) dpta and dptb are present.

Explanation:

The graph shows survival - rate data of different types of flies after infection. Type A flies (which likely have DptA) have better survival against A. sicerae, suggesting DptA confers defense against A. sicerae regardless of DptB presence. There is no clear indication for other options from the graph data.

Answer:

A. DptA confers defense against A. sicerae regardless of the presence of DptB.