CAIE IGCSE Biology 21.3.2 Examples of Genetic Modification

Practise linking inserted genes to human proteins or crop traits such as herbicide resistance, pest resistance and improved nutrition.

Exam points

link a human gene inserted into bacteria with production of the corresponding human protein
identify inserted crop genes for herbicide resistance, insect resistance or improved nutrition
state a specific benefit such as reduced crop damage, lower pesticide use or improved food quality

[Maximum number: 4]

A DNA molecule has two strands as shown in Fig. 6.1.

Fig. 6.1

A modern method for improving crop productivity is to cut out sections of DNA carrying a useful gene from one organism and place them into another organism.

A gene for producing a vaccine has been inserted into banana plants.

Give two other examples in which crop plants have been changed by inserting genes. State one advantage for each example.
example 1
advantage
example 2
advantage

drought/salt/pollution/metal/frost/stress/cold, resistant; increased, yield / productivity; extend range where crops can be grown;

herbicide resistance; increased yield / productivity;

pesticide resistance; increased yield / productivity;

crop plants produce own insecticides; less insecticide used; increased yield;

vitamin / nutrient, enrichment / $\beta$ carotene (Golden rice); increased nutritional value;

pathogen resistant/Bt; increased productivity / less pesticide use;

antigens / vaccines / pharmaceuticals; e.g. insulin cheap production of medicines;

flavour/texture/ripening;

Improved customer satisfaction/shelf life;

linked marking points 2+2

R bacteria (as not a crop plant)

A 'more profit' once.

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21.3.2—Genetic modification: (a) question 1