DP Biology (last assessment 2024)
Question 20N.3.HL.TZ0.a
Date | November 2020 | Marks available | [Maximum mark: 3] | Reference code | 20N.3.HL.TZ0.a |
Level | HL | Paper | 3 | Time zone | TZ0 |
Command term | Describe | Question number | a | Adapted from | N/A |
a.
[Maximum mark: 3]
20N.3.HL.TZ0.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.
Describe how the tobacco mosaic virus is used in the production of hepatitis B vaccine.
[3]
Markscheme
a. fusion between genes of (viral) capsid and hepatitis B antigen/HBsAg;
b. (transformed) virus infects tobacco plant;
c. tobacco plant expresses antigen/HBsAg;
d. HBsAg producing plants fed to animals;
e. animals produce anti-HBsAg antibodies;
Examiners report
Most have some knowledge of the usage of the tobacco mosaic virus but had difficulty in providing clear answers.
