Biology 9700 · AS & A Level · Principles of genetic technology

Principles of genetic technology — practice question

Oil seed rape (canola), Brassica napus, has been genetically altered so that it is resistant to herbicides containing glufosinate ammonium. The genetically modified (GM) oil seed rape carries the bar gene, which came from a soil bacterium. This gene codes for an enzyme that changes glufosinate ammonium into a non-toxic compound.
(a)[2]

Outline the advantages to farmers of growing glufosinate-resistant oil seed rape.

(b(i))[2]

The bar gene was inserted into the oil seed rape by means of plasmids. The plasmids also carried a promoter taken from thale cress, Arabidopsis thaliana. Outline the structure of a plasmid.

(b(ii))[3]

Explain how the properties of plasmids make them suitable for use during genetic modification programmes.

(b(iii))[2]

Describe the role of a promoter in gene expression.

(iii)[2]

Describe the role of a promoter in gene expression.

(c)

The pollen of oil seed rape is moved from one flower to another by insects. After pollination, fertilisation and seed formation may occur. One possible problem with growing glufosinate-resistant oil seed rape is that pollen from these plants could be carried to the flowers of wild relatives, such as wild radish, $\textit{Raphanus raphanistrum}$. This could cause genetic changes in these wild species. An experiment was carried out to find out whether glufosinate-resistant hybrids between GM oil seed rape and wild radish plants are likely to compete successfully with non-hybrid or non-resistant plants in the natural environment.

(c(i))[1]

Predict the diploid number of chromosomes in a hybrid between oil seed rape and wild radish.

(c(ii))[1]

Suggest how the researchers could have determined whether or not the $bar$ gene was present in the plants.

(c(iii))[3]

Many varieties of GM oil seed rape are male sterile, so they do not produce pollen. With reference to Table 3.1, suggest the environmental advantages of growing male sterile varieties of GM oil seed rape instead of GM varieties that produce pollen.

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