The diagram shows one approach being tested to protect maize plants from leaf-eating caterpillars. A gene from the bacterium Bacillus thuringiensis is place...
Question 1 Report
The diagram shows one approach being tested to protect maize plants from leaf-eating caterpillars. A gene from the bacterium Bacillus thuringiensis is placed into DNA in maize cells. The modified cells are grown into whole plants. When a caterpillar eats a leaf, the plant-made protein can damage the caterpillar's gut. Farmers may then need to use less insecticide, but scientists must consider effects on other organisms.
(a) Name the type of organism produced when maize cells contain a gene from a bacterium. [1]
(b) Describe the stages that transfer the bacterial gene into maize plants, using Fig. 1. [4]
(c) Explain how the transferred gene can result in death of a caterpillar that eats the maize leaf. [4]
(d) Use the information to explain one benefit and two possible concerns of growing these genetically modified plants. [4]
Answer Details
(a) Maize containing a gene from a bacterium is a transgenic organism, or a genetically modified organism. [1 mark]
(b) Scientists identify and isolate the required gene from Bacillus thuringiensis. [1 mark] They insert it into maize-cell DNA using a vector. [1 mark] They select maize cells that have received the gene. [1 mark] The selected modified cells are grown or regenerated into complete maize plants. [1 mark]
(c) The transferred gene is expressed in maize leaf cells. [1 mark] The cells make the bacterial protein. [1 mark] A caterpillar eats leaf tissue containing this protein. [1 mark] The protein damages the caterpillar's gut and can kill it. [1 mark]
(d) A benefit is that less insecticide may be needed, or crop damage is reduced so yield can increase. [1 mark] Two concerns are that caterpillars may evolve resistance [1 mark] and that the protein could affect non-target insects. [1 mark] Spread of the gene to related plants and effects on food chains are also acceptable concerns.
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