Question 20N.3.HL.TZ0.13c
| Date | November 2020 | Marks available | [Maximum mark: 1] | Reference code | 20N.3.HL.TZ0.13c |
| Level | HL | Paper | 3 | Time zone | TZ0 |
| Command term | Define | Question number | c | Adapted from | N/A |
Plant-derived proteins are likely to be safer for human use than those derived from mammalian cell cultures, as plant pathogens are not harmful to humans. The hepatitis B vaccine has been produced in tobacco plants.
In an experiment, soybean (Glycine max) cells were transformed using Agrobacterium tumefaciens to produce hepatitis B surface antigen (HBsAg). The amount of HBsAg made by the transformed soybean cells was measured at different times after transformation. The results are shown in the bar chart.
[Source: Reprinted by permission from Springer Nature from Plant Cell Reports.
Analysis of the limitations of hepatitis B surface antigen expression in soybean cell suspension cultures.
Ganapathi, T.R., Sunil Kumar, G.B., Srinivas, L., Revathi, C.J. and Bapat, V.A., © 2007. https://doi.org/10.1007/s00299-007-0379-7.]
The open reading frame (ORF) of HBsAg used in tobacco plants was the same one used in soybean plants. Define ORF.
[1]
DNA/nucleotide sequence with a start codon and stop codon coding for a polypeptide chain;
It was difficult for many candidates to specify that a start and a stop codon were necessary in the definition of an open reading frame.
