Microbiologists check strains of bacteria for antibiotic resistance by soaking paper discs in antibiotics and then placing them onto bacteria growing in Petri dishes. In Fig. 2.1, the paper discs in the middle of dishes E and F have been soaked with penicillin. Fig. 2.1 includes the labels “paper disc soaked in penicillin”, “zone where bacteria are growing”, and “zone where bacteria are no longer growing”. The dishes are labelled E and F.
(a)[1]
State the type of microorganism that makes penicillin.
(b)[2]
State and explain the evidence from Fig. 2.1 that indicates the bacteria in dish F are resistant to penicillin.
(c(i))[6]
Explain how bacteria become resistant to antibiotics and how people can reduce the issue of antibiotic resistance.
(c(ii))[1]
Explain why viral infections cannot be treated with antibiotics.
(d)[3]
Explain why bacteria are useful in biotechnology.
Worked solution & mark scheme
This 13-mark question has a full step-by-step worked solution and mark scheme. One marking point: “a fungus” …