Question 19M.3.SL.TZ2.9
| Date | May 2019 | Marks available | [Maximum mark: 7] | Reference code | 19M.3.SL.TZ2.9 |
| Level | SL | Paper | 3 | Time zone | TZ2 |
| Command term | Outline, State | Question number | 9 | Adapted from | N/A |
The diagram shows a method of production of transgenic plants and some of their uses.
[Source: Jian Yao, et al., (2015), International Journal of Molecular Science, 2015, 16(12),
28549–28565; https://doi.org/10.3390/ijms161226122]
Outline how the target gene is found using bioinformatics.
[2]
a. open reading frame finder «ORF finder» detects sections of a DNA molecule likely to be genes
OR
search for significant length of DNA coding from a start codon to a stop codon ✔
b. BLASTn used to compare gene sequences coding for similar proteins in other organisms/databases ✔
c. BLASTp used to detect similar proteins in other organisms/databases ✔
Accept methionine/AUG as start codon and UAA/UAG/UGA as stop codon.
Accept any other verified software program.
The question showed a diagram of the production of transgenic plants. Parts (a) and (c) proved difficult due to lack of specific vocabulary.
In this method of producing transgenic plants, state the name of the vector.
[1]
plasmid / Ti ✔
Part (b) was well answered.
In this method of producing transgenic plants, state how to detect successful uptake of the gene.
[1]
a. antibiotic resistance ✔
b. presence of a marker gene ✔
c. B galactosidase ✔
Accept green fluorescent protein/GFP or other example of a marker gene.
Part (b) was well answered.
In this method of producing transgenic plants, state one method used to introduce the vector into a plant.
[1]
a. infection by Agrobacterium tumefaciens
b. modification by calcium chloride / liposomes / electroporation / microinjection /gunshot / biolistics ✔
Part (b) was well answered.
Another method of plant transformation can be used to produce the hepatitis B vaccine. Outline the production of hepatitis B vaccine in tobacco plants.
[2]
a. tobacco mosaic virus/TMV modified to carry gene of hepatitis B «surface antigen/HBsAg» ✔
b.«tobacco mosaic» virus infects tobacco plants
OR
its genetic material is incorporated into plant cells ✔
c. tobacco plants produce hepatitis B antigen ✔
d. «antigen» induces formation of antibodies/immune response «in humans» ✔
Parts (a) and (c) proved difficult due to lack of specific vocabulary.