Question 18N.3.HL.TZ0.c
| Date | November 2018 | Marks available | [Maximum mark: 3] | Reference code | 18N.3.HL.TZ0.c |
| Level | HL | Paper | 3 | Time zone | TZ0 |
| Command term | Explain | Question number | c | Adapted from | N/A |
Golden rice (Oryza sativa, GR) is the generic name given to genetically modified rice that produces beta-carotene (provitamin A). Golden rice was created by transforming rice with the gene coding for the PSY protein (phytoene synthase) from daffodil (Narcissus pseudonarcissus) or from corn (Zea mays).
The picture shows variations of rice.
A White wild-type rice
B Yellow Golden rice expressing the gene coding for PSY from daffodil
C Orange Golden rice expressing the gene coding for PSY from corn
[Reprinted from TRENDS in Plant Science, 10(12), S. Al-Babili and P. Beyer, 'Golden Rice – five years on the road – five years to go?',
pp. 565--573, Copyright (2005), with permission from Elsevier. https://www.sciencedirect.com/journal/trends-in-plant-science]
Agrobacterium tumefaciens was used in the production of Golden rice varieties. Explain how this bacterium is used to produce genetically modified crop plants.
[3]
a. «Ti/tumour inducing» plasmid of A. tumefaciens/bacterium causes tumours/galls ✔
b. Ti incorporates genes «of β-carotene synthesis»
OR
Ti is used as a vector of the gene «for β-carotene» ✔
c. recombinant plasmids reintroduced into A. tumefaciens/bacterial cells ✔
d. bacteria infect rice plant cells ✔
e. the newly incorporated gene produces β-carotene/Golden Rice ✔
