Date | November 2018 | Marks available | 4 | Reference code | 18N.3.SL.TZ0.11 |
Level | Standard level | Paper | Paper 3 | Time zone | TZ0 / no time zone |
Command term | Discuss | Question number | 11 | Adapted from | N/A |
Question
The micrograph shows a T4 bacteriophage.
Discuss the use of bacteriophages in water systems.
Markscheme
a. bacteriophages are viruses of bacteria/prokaryotes ✔
b. each bacteriophage is specific to certain bacterial groups
OR
they can be used to target specific bacteria ✔
c. can be used in sewage plants
OR
can kill bacteria that cause water contamination/disinfect water
OR
can kill bacteria that form biofilms at water purification plants ✔
d. can kill strains resistant to antibiotics
OR
can kill strains resistant to chlorine/chemical disinfectants ✔
e. «presence of» bacteriophages also act as indicators of bacteria present ✔
f. generally not harmful to humans ✔