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Question 19N.3.SL.TZ0.9d

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Date November 2019 Marks available [Maximum mark: 3] Reference code 19N.3.SL.TZ0.9d
Level SL Paper 3 Time zone TZ0
Command term Outline Question number d Adapted from N/A
d.
[Maximum mark: 3]
19N.3.SL.TZ0.9d

A study was carried out in Brazil on the transfer of pollen (cross-pollination) from transgenic strains to non-transgenic strains of soybean (Glycine max). The transgenic crop was resistant to the herbicide glyphosate. The graph below shows the percentage of cross-pollination between transgenic and non-transgenic crops in fields separated by different distances.

[Source: S Abud, et al., (2007), Gene flow from transgenic to nontransgenic soybean plants in the Cerrado region of Brazil,
Genetics and Molecular Research, 6 (2), pages 445–452]

(d)

Outline how A. tumefaciens is used to introduce genes into soybeans.

[3]

Markscheme

a. genes to be transferred are introduced into a tumour-inducing/Ti plasmid/vector ✔

b. ‹embryo, seedling leaf› tissue is damaged/wounded / callus formed ✔

c. A. tumefaciens recognizes/is chemically attracted to damaged/wounded tissue ✔

d. A. tumefaciens transfers tumour-inducing/Ti plasmid/vector into plant cell ✔

e. plasmid integrates into plant cell genome ✔