(Form 5) 1.9.2 Useful Microorganisms (Structured Questions)

Question 1:
Figure 1 shows the result of an experiment to study the effect of different concentrations of an antibiotic on bacteria growth.

(a) State one hypothesis for this experiment. [1 mark]

(b) State the variables in this experiment.
(i) Manipulated variable [1 mark]
(ii) Responding variable [1 mark]

(c) Write down one observation for this experiment. [1 mark]

(d) What is meant by antibiotic based on this experiment (operational definition). [1 mark]

A higher concentration of an antibiotic will kill more bacteria.

Concentration of an antibiotic.

Clear area

The clear area that surrounds the antibiotic disc of high concentration is larger/ wider than the clear area that surrounds the antibiotic disc of low concentration.

Antibiotic is a substance that produces a clear area around the nutrient agar that contains bacteria.

Leave a Comment