| Date | November 2016 | Marks available | 1 | Reference code | 16N.3.SL.TZ0.9 |
| Level | Standard level | Paper | Paper 3 | Time zone | TZ0 |
| Command term | State | Question number | 9 | Adapted from | N/A |
Question
One method of inserting new genes into plants is by gene gun.
Outline how a gene gun inserts genes into plants.
Marker genes are often inserted together with the new gene. State the function of the marker genes.
Outline the characteristics of an open reading frame.
Explain, using an example, how gene transfer to a plant could help increase crop yield.
Markscheme
a. metal/tungsten/gold/bullet is coated with DNA/gene
Biolistics on its own not accepted.
b. «this DNA is» fired in to a leaf containing the target cells
Accept any plant part, plant suspension, etc.
c. DNA is released and incorporated in to some of the cells
marker genes can be detected easily and show the gene has been inserted
Allow a specific example (eg, green fluorescent protein).
a. a length of DNA that codes for a polypeptide/protein
OR
length of DNA that can be translated
b. begins with start codon/TAC/ATG/DNA for methionine
c. stop codon occurs after sufficient length OWTTE.
a. name of GM plant eg: Soybean.
b. source of the inserted gene eg: (Cry1Ac gene) from Bacillus thuringiensis.
OR
organism used for transfer eg: plasmid from Agrobacterium tumefaciens.
c. purpose of the transfer eg: increased resistance to glyphosate herbicide.
d. how it increases yield eg: reduced competition with weeds killed by glyphosate.
