Q1. A scientist investigated the effect of three different antibiotics
on three different types of bacteria, A, B and C.
This is the method used.
1. Grow bacteria A on an agar plate.
2. Put three separate paper discs each containing one of
the antibiotics (1, 2 and 3) onto the agar plate
3. Put the agar plate into an incubator for 48 hours.
4. Repeat steps 1-3 for bacteria B and for bacteria C.
Figure 1 shows the scientist's results.
Figure 1
Bacteria growing
Paper disc
Area where bacteria
are killed
Agar plate containing
bacteria A
Agar plate containing
bacteria B
Agar plate containing
bacteria C
(a) Compare the effectiveness of the three antibiotics at
killing the different types of bacteria.
