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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.

[1]
a.

Rotavirus causes diarrhea and vomiting. Explain why viral diseases cannot be treated using antibiotics.

[2]
b.

State an application of plasmids in biotechnology.

[1]
c.

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.

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]

b.

transfer/vector of genetic material/genes/DNA fragments

OR

to produce insulin/useful protein

c.

Examiners report

[N/A]
a.
[N/A]
b.
[N/A]
c.

Syllabus sections

Core » Topic 1: Cell biology » 1.2 Ultrastructure of cells
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Core » Topic 1: Cell biology
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