Date | November 2017 | Marks available | 1 | Reference code | 17N.2.SL.TZ0.02 |
Level | Standard level | Paper | Paper 2 | Time zone | TZ0 / no time zone |
Command term | State | Question number | 02 | Adapted from | N/A |
Question
The figure shows a transmission electron micrograph of rotavirus particles. Each rotavirus is about 70 nanometres in diameter.
[Source: CDC / Dr. Erskine L. Palmer]
State a reason for using an electron microscope to view this virus rather than a light microscope.
Rotavirus causes diarrhea and vomiting. Explain why viral diseases cannot be treated using antibiotics.
State an application of plasmids in biotechnology.
Markscheme
electron microscope has greater resolution/magnification
OR
70 nm is too small/viruses are too small to be viewed by a light microscope
a. viruses are not living
b. viruses lack metabolism/lack enzymes «for metabolism»/lack cell walls
c. antibiotics target metabolic «pathways»/cell wall production
[Max 2 Marks]
transfer/vector of genetic material/genes/DNA fragments
OR
to produce insulin/useful protein