Question 1
Unit 4 style
A Level only (what this means)
A Level only: only in the full A Level, not the AS Level. AS Level students can skip it. What the labels meanWhich statement describes a bacteriostatic antibiotic?
- It kills bacteria by making holes in the cell-surface membrane
- It prevents bacteria multiplying without necessarily killing them
- It kills viruses in infected cells
- It destroys the immune cells that target bacteria
Show mark scheme for question 1
Question 2
Unit 4 style
A Level only (what this means)
A Level only: only in the full A Level, not the AS Level. AS Level students can skip it. What the labels meanPenicillin is a bactericidal antibiotic that prevents the formation of cross-links in the bacterial cell wall. Explain why penicillin kills bacteria but does not harm human cells, and why it does not kill viruses.
Show mark scheme for question 2
Question 3
Unit 6 style
A Level only (what this means)
A Level only: only in the full A Level, not the AS Level. AS Level students can skip it. What the labels meanA student investigated the effect of four antibiotics on a bacterium using discs on an agar plate. Disc E was a control. (a) Calculate the area of the zone of inhibition around antibiotic C. (2) (b) State which antibiotic was most effective and give a reason. (2) (c) Explain the purpose of disc E, and suggest what it contained. (2)
| Disc | Diameter of zone / mm |
|---|---|
| A | 18 |
| B | 0 |
| C | 11 |
| D | 25 |
| E (control) | 0 |
Show mark scheme for question 3
Question 4
Unit 6 style
A Level only (what this means)
A Level only: only in the full A Level, not the AS Level. AS Level students can skip it. What the labels meanDescribe how the risks are reduced when an investigation into the effect of antibiotics on bacteria is carried out in a school laboratory.
Show mark scheme for question 4
Question 5
Unit 4 style
A Level only (what this means)
A Level only: only in the full A Level, not the AS Level. AS Level students can skip it. What the labels meanMRSA is a common cause of hospital-acquired infection. Explain how an understanding of the causes of hospital-acquired infections has led to changes in hospital practice and in the prescription of antibiotics.
Show mark scheme for question 5
Question 6
Unit 4 style
A Level only (what this means)
A Level only: only in the full A Level, not the AS Level. AS Level students can skip it. What the labels meanA doctor refuses to prescribe antibiotics to a patient with a cold. Give three reasons that support the doctor's decision.