Antibiotics, culturing microorganisms and monoclonal antibodies

EasyMediumHard
123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566
Question 29
Easy

A student investigated the antimicrobial properties of a newly isolated compound from a soil fungus.

They placed a filter paper disc soaked in the compound dissolved in dimethyl sulfoxide (Disc A) on one half of an agar plate spread with Staphylococcus aureus bacteria.

A control filter paper disc soaked only in dimethyl sulfoxide (Disc C) was placed on the other half of the agar plate.

The plate was incubated at 25 °C for 48 hours. The results are shown below.

An agar plate showing a lawn of bacterial growth. On the left side, Disc A has a distinct, clear circular zone of inhibition around it. On the right side, Disc C has no clear zone around it.

The diameter of the zone of inhibition around Disc A is 19 mm.

Calculate the area of this zone of inhibition. Use the equation:

Area=πr2 \text{Area} = \pi r^2 Area=πr2

Use a value of 3.14 for π\piπ.

Give your answer to 1 decimal place and include the unit.

[3]

Antibiotics, culturing microorganisms and monoclonal antibodies Questions

  1. GCSE
  2. /Biology
  3. /Antibiotics, culturing microorganisms and monoclonal antibodies