A-LevelBiologyGenetic technology9700/41 · Oct/Nov 2025 · Q89 Marks

LibertyLink® soybean is a genetically modified crop. It was first grown in 1996 and used in food products from 1998. It has been grown in 6 countries and used in food products in 21 countries. Table 8.1 summarises the modifications made to the soybean plant to produce LibertyLink® soybean. Table 8.1 name of introduced gene pat gene donor organism Streptomyces viridochromogenes gene product phosphinothricin N-acetyltransferase function of gene product stops action of glufosinate, a herbicide

(a)Explain how the modification made to produce LibertyLink® soybean may help to solve the global demand for food.[4]
(b)(i)Name the type of enzyme that could be used to cut out the pat gene from S. viridochromogenes.[1]
(b)(ii)Name the enzyme that could be used to join the pat gene to a plasmid by forming phosphodiester bonds.[1]
(c)Suggest reasons why LibertyLink® soybean is used in food products in 21 countries but only grown in 6 countries.[3]

Mark scheme

Marking points from the official mark scheme (Oct/Nov 2025). The mark or mark type is shown in brackets.

[4] (a) any four from: 1 (Liberty Link soybean / it, is) not harmed by / not killed by / resistant to, herbicide / glufosinate ; 2 herbicide / glufosinate, kills, weeds / unwanted plants ; 3 reduces / removes / less / no, competition (with, weeds / unwanted plants) ; 4 ref. to (sun)light / water / (named) soil minerals ; 5 higher yield or more crop, harvested / produced ; 6 AVP ;
[1] (b)(i) restriction, enzyme / endonuclease ;
[1] (b)(ii) (DNA) ligase ;
[3] (c) any three from: some/other/21, countries: 1 may, have, unsuitable / described problem in, climate / weather / soil ; 2 no regulatory approval / may have banned (GM / Liberty Link) ; 3 may have, (activist) groups / people, opposed to GM crops ; 4 may not have land space available ; 5 may have banned, herbicide / glufosinate ; 6 AVP ;

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