Question

1. propose reasons why an antibiotic may not be as effective at inhibiting e. coli as it is against b. cereus. 4. classify each of the tested antibiotics as limited spectrum or broad spectrum. explain your responses.

Explanation:

For question 3, possible reasons include differences in cell - wall structure (E. coli is Gram - negative with an outer membrane that can act as a barrier to antibiotics, while B. cereus is Gram - positive), presence of antibiotic - resistance genes in E. coli, and differences in metabolic pathways that the antibiotic targets. For question 4, limited - spectrum antibiotics target a narrow range of bacteria (usually either Gram - positive or Gram - negative), while broad - spectrum antibiotics target a wide range of both Gram - positive and Gram - negative bacteria. Classification would depend on the specific bacteria the antibiotic is effective against. If it works mainly on one type (e.g., only Gram - positive), it's limited - spectrum; if it works on both, it's broad - spectrum.

Answer:

1. Reasons: Cell - wall structure differences (E. coli has outer membrane), presence of resistance genes in E. coli, different metabolic targets.
2. Classification depends on bacteria targeted. Limited - spectrum: Works mainly on one type (e.g., only Gram - positive). Broad - spectrum: Works on both Gram - positive and Gram - negative.