A biotechnology company is developing a genetically modified (GM) variety of rice that expresses high levels of human lactoferrin (an iron-binding protein) in its grains to help treat iron-deficiency anaemia.
Which of the following is not a valid or necessary step in the production and identification of these GM rice plants?
Synthesising the lactoferrin gene using reverse transcriptase on mature mRNA isolated from human cells, rather than using genomic DNA.
Inserting a plant promoter sequence upstream of the human lactoferrin cDNA that is specifically activated by transcription factors in rice endosperm cells.
Designing PCR primers that are complementary to human tRNA molecules to amplify the lactoferrin cDNA from the transformed plant tissue during screening.
Using a marker gene, such as one conferring resistance to a specific herbicide, to identify and select the rice cells that have successfully integrated the plasmid.
14 exam-style questions on OCR A A Level Biology Manipulating genomes. Each one has a worked solution and a mark scheme showing where the marks go.