1.1. Extended Only

Microbiologists test strains of bacteria for antibiotic resistance.

They do this by soaking paper discs in antibiotics and placing them on bacteria growing in Petri dishes.

The paper discs in the centre of Petri dishes E and F in Fig. 1 have been soaked in penicillin. 

Fig. 1

State the type of microorganism that produces penicillin.

1.2. Extended Only

State and explain the evidence from Fig. 1 that suggests that the bacteria in dish F are resistant to penicillin.

1.3. Extended Only

(i)

Explain how bacteria become resistant to antibiotics and how humans can reduce the problem of antibiotic resistance. 

[6]

(ii)

Explain why viral infections cannot be treated with antibiotics.

[1]

1.4. Extended Only

Some bacteria and viruses cause disease but many are useful to the biotechnology industry.

Explain why bacteria are useful in biotechnology.