Date | November 2016 | Marks available | 1 | Reference code | 16N.3.HL.TZ0.10 |
Level | Higher level | Paper | Paper 3 | Time zone | TZ0 / no time zone |
Command term | State | Question number | 10 | Adapted from | N/A |
Question
Crop genetic engineering was performed to improve drought tolerance in tomato plants (Solanum lycopersicum) by adding a gene from an edible fungus (Flammulina velutipes). The cotyledons of tomato plants were cut and co-cultivated with Agrobacterium tumefaciens containing the transgenic Ti plasmid. Plates containing kanamycin were used to select for transgenic cotyledons. The graph shows concentrations of three constituents of the wax that coats wild type plants (control) and transgenic tomato plants.
Outline the use of kanamycin in the selection of transgenic cotyledons.
State how the sequence of the target gene from the fungus could be identified using a bioinformatics tool.
Suggest whether the results of this experiment show that these transgenic tomato plants are more resistant to drought.
Markscheme
a. kanamycin resistance as marker gene
b. when organisms grown in kanamycin, only resistant survive
OR
those that took up resistance/cloned ones survive
database/NCBI search to find target gene/OWTTE
OR
search for target gene in other/related organisms
Allow other named database.
Please check unfamiliar names for authenticity.
a. more wax deposition constituents «in leaves» of transgenic than control plants
b. wax is waterproof
c. less evaporation from «waxy» leaves «protects from drought»