Question 19N.3.SL.TZ0.9
| Date | November 2019 | Marks available | [Maximum mark: 6] | Reference code | 19N.3.SL.TZ0.9 |
| Level | SL | Paper | 3 | Time zone | TZ0 |
| Command term | Deduce, Outline, Suggest | Question number | 9 | Adapted from | N/A |
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]
Suggest one undesirable consequence of cross-pollination involving glyphosate resistant crop plants with other plants.
[1]
transfer of resistance genes to non-transgenic/organic crops
OR
transfer of resistance genes to wild relatives/development of weed resistance ✔
Using the data, suggest one recommendation to farmers who plant transgenic soybeans.
[1]
separate fields by at least 5m because at this distance no cross pollination occurs ✔
Needs a reason.
Agrobacterium tumefaciens stains pink or red with the Gram stain. Deduce from this result what type of bacterium A. tumefaciens is.
[1]
«Gram» negative ✔
Outline how A. tumefaciens is used to introduce genes into soybeans.
[3]
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 ✔
